CREDIT AGREEMENT Dated as of March 31, 2006 Among TC PIPELINES, LP as Borrower (By itsGeneral Partner TC PipeLines GP, Inc.) and THE INITIAL LENDERS NAMED HEREIN asInitial Lenders and CITICORP NORTH AMERICA, INC. asAdministrative Agent and MIZUHO CORPORATE BANK, LTD. and THE BANK OF TOKYO-MITSUBISHI UFJ, LTD., HOUSTON AGENCY asCo-Documentation Agents and CITICORP NORTH AMERICA, INC. asAdministrative Agent and CITIGROUP GLOBAL MARKETS INC. and UBS LOAN FINANCE LLC asJoint Lead Arrangers and Joint Book Managers

Exhibit 10.5

CREDIT AGREEMENT

Dated as of March 31, 2006

Among

TC PIPELINES, LP

as Borrower

(By its General Partner TC PipeLines GP, Inc.)

and

THE INITIAL LENDERS NAMED HEREIN

as Initial Lenders

and

CITICORP NORTH AMERICA, INC.

as Administrative Agent

and

MIZUHO CORPORATE BANK, LTD.

and

THE BANK OF TOKYO-MITSUBISHI UFJ, LTD., HOUSTON AGENCY

as Co-Documentation Agents

and

CITICORP NORTH AMERICA, INC.

as Administrative Agent

and

CITIGROUP GLOBAL MARKETS INC.

and

UBS LOAN FINANCE LLC

as Joint Lead Arrangers and Joint Book Managers

TABLE OF CONTENTS

Schedules

Schedule I - List of Applicable Lending Offices

[Schedule 3.01(b) - Disclosed Litigation]

Schedule 5.02(a) - Existing Liens

Exhibits

CREDIT AGREEMENT

Dated as of March 31, 2006

TC PIPELINES, LP, a Delaware limited partnership (the “Borrower”), by its General Partner TC PipeLines GP, Inc., the banks, financial institutions and other institutional lenders (the “Initial Lenders”) listed on the signature pages hereof, and CITICORP NORTH AMERICA, INC. (“CNAI”), as agent (the “Agent”) for the Lenders (as hereinafter defined), agree as follows:

ARTICLE I

DEFINITIONS AND ACCOUNTING TERMS

SECTION 1.01.  Certain Defined Terms.  As used in this Agreement, the following terms shall have the following meanings (such meanings to be equally applicable to both the singular and plural forms of the terms defined):

“Acquisition” means the Borrower’s acquisition of an additional 20% interest in the Northern Border Pipeline Company.

“Adjusted Cash Flow” means, with reference to any period (i) the net income (or loss) of the Borrower and its consolidated Subsidiaries for such period calculated on a consolidated basis in accordance with GAAP, plus (ii) to the extent taken into account in determining such net income (or loss), the sum of interest expense, expense for taxes paid or accrued, depreciation, amortization and extraordinary losses incurred other than in the ordinary course of business, minus (iii) to the extent taken into account in determining such net income (or loss), extraordinary gains realized other than in the ordinary course of business, minus (iv) to the extent taken into account in determining such net income (or loss), equity earnings of any Person in which the Borrower or any of its consolidated Subsidiaries has an interest (which interest does not cause the net income of such Person to be consolidated with the net income of the Borrower and its consolidated Subsidiaries in accordance with GAAP), plus (v) the aggregate amount of all cash dividends and other distributions of cash actually received by the Borrower or any of its consolidated Subsidiaries during such period from any Person in which the Borrower or any of its consolidated Subsidiaries has an interest (which interest does not cause the net income of such other Person to be consolidated with the net income of the Borrower and its consolidated Subsidiaries in accordance with GAAP).

“Advance” means an advance by a Lender to the Borrower as part of a Borrowing under Section 2.01 and refers to a Base Rate Advance or a Eurodollar Rate Advance (each of which shall be a “Type” of Advance).

“Affiliate” means, as to any Person, any other Person that, directly or indirectly, controls, is controlled by or is under common control with such Person or is a director or officer of such Person. For purposes of this definition the term “control” (including the terms “controlling”, “controlled by” and “under common control with”) of a Person means the possession, direct or indirect, of the power to direct or cause the direction of the management and policies of such Person, whether through the ownership of Voting Stock, by contract or otherwise, provided, that, for purposes of Section 5.01(h), each of Northern Border and Tuscarora shall be deemed to be an Affiliate of the Borrower as long as it qualifies as a Significant Subsidiary.

“Agent” has the meaning specified in the recitals hereto.

“Agent’s Account” means the account of the Agent maintained by the Agent at Citibank at its office at 388 Greenwich Street, New York, New York 10013, Account No. 36852248, Attention:  Bank Loan Syndications.

“Applicable Lending Office” means, with respect to each Lender, such Lender’s Domestic Lending Office in the case of a Base Rate Advance and such Lender’s Eurodollar Lending Office in the case of a Eurodollar Rate Advance.

“Applicable Margin” means as of any date, a percentage per annum determined by reference to the Leverage Ratio in effect on such date as set forth below:

provided, that the Applicable Margin will be increased by 0.125% per annum on the date that is 12 months after the Effective Date and will be further increased by 0.25% per annum on the date that is 18 months after the Effective Date. The Applicable Margin shall be determined by reference to the Leverage Ratio in effect from time to time; provided, that no reduction in the Applicable Margin shall be effective until three Business Days after the date on which the Agent receives the financial statements required to be delivered pursuant to Section 5.01(i)(i) or (ii), as the case may be, and a certificate of the Chief Financial Officer or Controller of the General Partner of the Borrower demonstrating such ratio.

“Applicable Percentage” means, as of any date, a percentage per annum determined by reference to the Leverage Ratio in effect on such date as set forth below:

The Applicable Percentage shall be determined by reference to the Leverage Ratio in effect from time to time; provided, that no reduction in the Applicable Percentage shall be effective until three Business Days after the date on which the Agent receives the financial statements required to be delivered pursuant to Section 5.01(i)(i) or (ii), as the case may be, and a certificate of the Chief Financial Officer of the Borrower demonstrating such ratio.

“Assignment and Acceptance” means an assignment and acceptance entered into by a Lender and an Eligible Assignee, and accepted by the Agent, in substantially the form of Exhibit C hereto.

“Base Rate” means a fluctuating interest rate per annum in effect from time to time, which rate per annum shall at all times be equal to the higher of:

(a)           the rate of interest announced publicly by Citibank in New York, New York, from time to time, as Citibank’s base rate; and

(b)           ½ of one percent per annum above the Federal Funds Rate.

“Base Rate Advance” means an Advance that bears interest as provided in Section 2.06(a)(i).

“Borrower” has the meaning specified in the recitals hereto.

“Borrower Information” has the meaning specified in Section 8.08.

“Borrowing” means a borrowing consisting of simultaneous Advances of the same Type made by the Lenders.

“Business Day” means a day of the year on which banks are not required or authorized by law to close in New York City, Calgary, Canada and, if the applicable Business Day relates to any Eurodollar Rate Advances, on which dealings are carried on in the London interbank market.

“Change in Accounting Principles” means changes in accounting principles required by the promulgation of any rule, regulation, pronouncement or opinion by the Financial Accounting Standards Board of the American Institute of Certified Public Accountants or any successor thereto, the SEC or, if applicable, the Public Company Accounting Oversight Board.

“Citibank” means Citibank, N.A.

“Commitment” means as to any Lender (a) the amount set forth opposite such Lender’s name on Schedule I hereto as such Lender’s “Commitment” or (b) if such Lender has entered into any Assignment and Acceptance, the amount set forth for such Lender in the Register maintained by the Agent pursuant to Section 8.07(d), as such amount may be reduced pursuant to Section 2.04.

“Consolidated” refers to the consolidation of accounts in accordance with GAAP.

“Convert”, “Conversion” and “Converted” each refers to a conversion of Advances of one Type into Advances of the other Type pursuant to Section 2.07 or 2.08.

“Covenant Indebtedness” of any Person means all items that, in accordance with GAAP, would be classified as indebtedness on a Consolidated balance sheet of such Person.

“Debt” of any Person means, without duplication, (a) all indebtedness of such Person for borrowed money, (b) all obligations of such Person for the deferred purchase price of property or services (other than trade payables incurred in the ordinary course of such Person’s business), (c) all obligations of such Person evidenced by notes, bonds, debentures or other similar instruments, (d) all obligations of such Person created or arising under any conditional sale or other title retention agreement with respect to property acquired by such Person (even though the rights and remedies of the seller or lender under such agreement in the event of default are limited to repossession or sale of such property), (e) all obligations of such Person as lessee under leases that have been or should be, in accordance with GAAP, recorded as capital leases, (f) all obligations, contingent or otherwise, of such Person in respect of acceptances, letters of credit or similar extensions of credit, (g) all Debt of others referred to in clauses (a) through (f) above or clause (h) below and other payment obligations (collectively, “Guaranteed Debt”) guaranteed directly or indirectly in any manner by such Person, or in effect guaranteed directly or indirectly by such Person through an agreement (1) to pay or purchase such Guaranteed Debt or to advance or supply funds for the payment or purchase of such Guaranteed Debt, (2) to purchase, sell or lease (as lessee or lessor) property, or to purchase or sell services, primarily for the purpose of enabling the debtor to make payment of such Guaranteed Debt or to assure the holder of such Guaranteed Debt against loss, (3) to supply funds to or in any other manner invest in the debtor (including any agreement to pay for property or services irrespective of whether such property is received or such services are rendered) or (4) otherwise to assure a creditor against loss, and (h) all Debt referred to in clauses (a) through (g) above (including Guaranteed Debt)

secured by (or for which the holder of such Debt has an existing right, contingent or otherwise, to be secured by) any Lien on property (including, without limitation, accounts and contract rights) owned by such Person, even though such Person has not assumed or become liable for the payment of such Debt, provided, that if such Person is not liable for such obligation, the amount of such Person’s Debt with respect thereto shall be deemed to be the lesser of the stated amount of such obligation and the value of the property subject to such Lien.

“Default” means any Event of Default or any event that would constitute an Event of Default but for the requirement that notice be given or time elapse or both.

“Disclosed Litigation” has the meaning specified in Section 3.01(b).

“Domestic Lending Office” means, with respect to any Lender, the office of such Lender specified as its “Domestic Lending Office” opposite its name on Schedule I hereto or in the Assignment and Acceptance pursuant to which it became a Lender, or such other office of such Lender as such Lender may from time to time specify to the Borrower and the Agent.

“Effective Date” has the meaning specified in Section 3.01.

“Eligible Assignee” means (i) a Lender; (ii) an Affiliate of a Lender; and (iii) any other Person approved by the Agent and, unless an Event of Default has occurred and is continuing at the time any assignment is effected in accordance with Section 8.07, the Borrower, such approval not to be unreasonably withheld or delayed; provided, however, that neither the Borrower nor an Affiliate of the Borrower shall qualify as an Eligible Assignee.

“Environmental Action” means any action, suit, demand, demand letter, claim, notice of non-compliance or violation, notice of liability or potential liability, investigation, proceeding, consent order or consent agreement relating in any way to any Environmental Law, Environmental Permit or Hazardous Materials or arising from alleged injury or threat of injury to health, safety or the environment, including, without limitation, (a) by any governmental or regulatory authority for enforcement, cleanup, removal, response, remedial or other actions or damages and (b) by any governmental or regulatory authority or any third party for damages, contribution, indemnification, cost recovery, compensation or injunctive relief.

“Environmental Law” means any federal, state, local or foreign statute, law, ordinance, rule, regulation, code, order, judgment, decree or judicial or agency interpretation, policy or guidance relating to pollution or protection of the environment, health, safety or natural resources, including, without limitation, those relating to the use, handling, transportation, treatment, storage, disposal, release or discharge of Hazardous Materials.

“Environmental Permit” means any permit, approval, identification number, license or other authorization required under any Environmental Law.

“ERISA” means the Employee Retirement Income Security Act of 1974, as amended from time to time, and the regulations promulgated and rulings issued thereunder.

“ERISA Affiliate” means any Person that for purposes of Title IV of ERISA is a member of the Borrower’s controlled group, or under common control with the Borrower, within the meaning of Section 414 of the Internal Revenue Code.

“ERISA Event” means (a) (i) the occurrence of a reportable event, within the meaning of Section 4043 of ERISA, with respect to any Plan unless the 30-day notice requirement with respect to such event has been waived by the PBGC, or (ii) the requirements of subsection (1) of Section 4043(b) of ERISA (without regard to subsection (2) of such Section) are met with respect to a contributing sponsor, as

defined in Section 4001(a)(13) of ERISA, of a Plan, and an event described in paragraph (9), (10), (11), (12) or (13) of Section 4043(c) of ERISA is reasonably expected to occur with respect to such Plan within the following 30 days; (b) the application for a minimum funding waiver with respect to a Plan; (c) the provision by the administrator of any Plan of a notice of intent to terminate such Plan pursuant to Section 4041(a)(2) of ERISA (including any such notice with respect to a plan amendment referred to in Section 4041(e) of ERISA); (d) the cessation of operations at a facility of the Borrower or any ERISA Affiliate in the circumstances described in Section 4062(e) of ERISA; (e) the withdrawal by the Borrower or any ERISA Affiliate from a Multiple Employer Plan during a plan year for which it was a substantial employer, as defined in Section 4001(a)(2) of ERISA; (f)  the conditions for the imposition of a lien under Section 302(f) of ERISA shall have been met with respect to any Plan; (g) the adoption of an amendment to a Plan requiring the provision of security to such Plan pursuant to Section 307 of ERISA; or (h) the institution by the PBGC of proceedings to terminate a Plan pursuant to Section 4042 of ERISA, or the occurrence of any event or condition described in Section 4042 of ERISA that constitutes grounds for the termination of, or the appointment of a trustee to administer, a Plan.

“Eurocurrency Liabilities” has the meaning assigned to that term in Regulation D of the Board of Governors of the Federal Reserve System, as in effect from time to time.

“Eurodollar Lending Office” means, with respect to any Lender, the office of such Lender specified as its “Eurodollar Lending Office” opposite its name on Schedule I hereto or in the Assignment and Acceptance pursuant to which it became a Lender (or, if no such office is specified, its Domestic Lending Office), or such other office of such Lender as such Lender may from time to time specify to the Borrower and the Agent.

“Eurodollar Rate” means, for any Interest Period for each Eurodollar Rate Advance comprising part of the same Borrowing, an interest rate per annum equal to the rate per annum obtained by dividing (a) the rate per annum (rounded upward to the nearest whole multiple of 1/16 of 1% per annum) appearing on Moneyline Telerate Markets Page 3750 (or any successor page) as the London interbank offered rate for deposits in U.S. dollars at approximately 11:00 A.M. (London time) two Business Days prior to the first day of such Interest Period for a term comparable to such Interest Period or, if for any reason such rate is not available, the average (rounded upward to the nearest whole multiple of 1/16 of 1% per annum, if such average is not such a multiple) of the rate per annum at which deposits in U.S. dollars are offered by the principal office of each of the Reference Banks in London, England to prime banks in the London interbank market at 11:00 A.M. (London time) two Business Days before the first day of such Interest Period in an amount substantially equal to such Reference Bank’s Eurodollar Rate Advance comprising part of such Borrowing to be outstanding during such Interest Period and for a period equal to such Interest Period by (b) a percentage equal to 100% minus the Eurodollar Rate Reserve Percentage for such Interest Period. If the Moneyline Telerate Markets Page 3750 (or any successor page) is unavailable, the Eurodollar Rate for any Interest Period for each Eurodollar Rate Advance comprising part of the same Borrowing shall be determined by the Agent on the basis of applicable rates furnished to and received by the Agent from the Reference Banks two Business Days before the first day of such Interest Period, subject, however, to the provisions of Section 2.07.

“Eurodollar Rate Advance” means an Advance that bears interest as provided in Section 2.06(a)(ii).

“Eurodollar Rate Reserve Percentage” for any Interest Period for all Eurodollar Rate Advances comprising part of the same Borrowing means the reserve percentage applicable two Business Days before the first day of such Interest Period under regulations issued from time to time by the Board of Governors of the Federal Reserve System (or any successor) for determining the maximum reserve requirement (including, without limitation, any emergency, supplemental or other marginal reserve requirement) for a member bank of the Federal Reserve System in New York City with respect to liabilities or assets consisting of or including Eurocurrency Liabilities (or with respect to any other category of liabilities that

includes deposits by reference to which the interest rate on Eurodollar Rate Advances is determined) having a term equal to such Interest Period.

“Events of Default” has the meaning specified in Section 6.01.

“Federal Funds Rate” means, for any period, a fluctuating interest rate per annum equal for each day during such period to the weighted average of the rates on overnight Federal funds transactions with members of the Federal Reserve System arranged by Federal funds brokers, as published for such day (or, if such day is not a Business Day, for the next preceding Business Day) by the Federal Reserve Bank of New York, or, if such rate is not so published for any day that is a Business Day, the average of the quotations for such day on such transactions received by the Agent from three Federal funds brokers of recognized standing selected by it.

“GAAP” has the meaning specified in Section 1.03.

“General Partner” means TC PipeLines GP, Inc.

“Hazardous Materials” means (a) petroleum and petroleum products, byproducts or breakdown products, radioactive materials, asbestos-containing materials, polychlorinated biphenyls and radon gas and (b) any other chemicals, materials or substances designated, classified or regulated as hazardous or toxic or as a pollutant or contaminant under any Environmental Law.

“Hedge Agreements” means interest rate swap, cap or collar agreements, interest rate future or option contracts, currency swap agreements, currency future or option contracts and other similar agreements.

“Hedge Termination Value” means, in respect of any one or more Hedge Agreements, after taking into account the effect of any legally enforceable netting agreement relating to such Hedge Agreements, (a) for any date on or after the date such Hedge Agreements have been closed out and termination value(s) determined in accordance therewith, such termination value(s), and (b) for any date prior to the date referenced in clause (a) the amount(s) determined as the mark-to-market value(s) for such Hedge Agreements, as determined based upon one or more mid-market or other readily available quotations provided by any recognized dealer in such Hedge Agreements (which may include any Lender).

“Information Memorandum” means the confidential information memorandum dated March 13, 2006 used by the Agent in connection with the syndication of the Commitments.

“Initial Lenders” has the meaning specified in the recitals hereto.

“Interest Expense” means, for any period, total interest expense determined in accordance with GAAP.

“Interest Period” means, for each Eurodollar Rate Advance comprising part of the same Borrowing, the period commencing on the date of such Eurodollar Rate Advance or the date of the Conversion of any Base Rate Advance into such Eurodollar Rate Advance and ending on the last day of the period selected by the Borrower pursuant to the provisions below and, thereafter, each subsequent period commencing on the last day of the immediately preceding Interest Period and ending on the last day of the period selected by the Borrower pursuant to the provisions below. The duration of each such Interest Period shall be one, two, three or six months, and subject to clause (c) of this definition, nine or twelve months, as the Borrower may, upon notice received by the Agent not later than 11:00 A.M. (New York City time) on the third Business Day prior to the first day of such Interest Period, select; provided, however, that:

(a)           the Borrower may not select any Interest Period that ends after the Termination Date;

(b)           Interest Periods commencing on the same date for Eurodollar Rate Advances comprising part of the same Borrowing shall be of the same duration;

(c)           the Borrower shall not be entitled to select an Interest Period having duration of nine or twelve months unless, by 2:00 P.M. (New York City time) on the third Business Day prior to the first day of such Interest Period, each Lender notifies the Agent that such Lender will be providing funding for such Borrowing with such Interest Period (the failure of any Lender to so respond by such time being deemed for all purposes of this Agreement as an objection by such Lender to the requested duration of such Interest Period); provided that, if any or all of the Lenders object to the requested duration of such Interest Period, the duration of the Interest Period for such Borrowing shall be one, two, three or six months, as specified by the Borrower requesting such Borrowing in the applicable Notice of Borrowing as the desired alternative to an Interest Period of nine or twelve months;

(d)           whenever the last day of any Interest Period would otherwise occur on a day other than a Business Day, the last day of such Interest Period shall be extended to occur on the next succeeding Business Day, provided, however, that, if such extension would cause the last day of such Interest Period to occur in the next following calendar month, the last day of such Interest Period shall occur on the next preceding Business Day; and

(e)           whenever the first day of any Interest Period occurs on a day of an initial calendar month for which there is no numerically corresponding day in the calendar month that succeeds such initial calendar month by the number of months equal to the number of months in such Interest Period, such Interest Period shall end on the last Business Day of such succeeding calendar month.

“Internal Revenue Code” means the Internal Revenue Code of 1986, as amended from time to time, and the regulations promulgated and rulings issued thereunder.

“Lenders” means the Initial Lenders and each Person that shall become a party hereto pursuant to Section 8.07.

“Leverage Ratio” means, as of any date, the ratio of Covenant Indebtedness of the Borrower on such date to Adjusted Cash Flow of the Borrower for the period of four fiscal quarters most recently ended on or immediately prior to such date.

“Lien” means any lien, security interest or other charge or encumbrance of any kind, or any other type of preferential arrangement, including, without limitation, the lien or retained security title of a conditional vendor and any easement, right of way or other encumbrance on title to real property.

“Material Adverse Change” means any material adverse change in the business, condition (financial or otherwise), operations, performance or properties of the Borrower, its Subsidiaries, Northern Border and Tuscarora taken as a whole.

“Material Adverse Effect” means a material adverse effect on (a) the business, condition (financial or otherwise), operations, performance or properties of the Borrower, its Subsidiaries, Northern Border and Tuscarora taken as a whole, (b) the rights and remedies of the Agent or any Lender under this Agreement or any Note or (c) the ability of the Borrower to perform its obligations under this Agreement or any Note.

“Maturity Date” means the second anniversary of the Effective Date.

“Multiemployer Plan” means a multiemployer plan, as defined in Section 4001(a)(3) of ERISA, to which the Borrower or any ERISA Affiliate is making or accruing an obligation to make contributions, or has within any of the preceding five plan years made or accrued an obligation to make contributions.

“Multiple Employer Plan” means a single employer plan, as defined in Section 4001(a)(15) of ERISA, that (a) is maintained for employees of the Borrower or any ERISA Affiliate and at least one Person other than the Borrower and the ERISA Affiliates or (b) was so maintained and in respect of which the Borrower or any ERISA Affiliate could have liability under Section 4064 or 4069 of ERISA in the event such plan has been or were to be terminated.

“Net Cash Proceeds” means, with respect to any sale, lease, transfer or other disposition of any asset or the incurrence or issuance of any Debt or the sale or issuance of any equity by the Borrower, the aggregate amount of cash received from time to time (whether as initial consideration or through payment or disposition of deferred consideration) by or on behalf of such Person in connection with such transaction after deducting therefrom only (without duplication) (a) reasonable and customary brokerage commissions, underwriting fees and discounts, legal and accounting fees, filing fees, finder’s fees and other similar fees and commissions, (b) the amount of taxes estimated in good faith by the Borrower to be payable by the Borrower or any of its Subsidiaries in connection with or as a result of such transaction, (c) the amount of any Debt secured by a Lien on such asset, (d) in the case of any receipt of proceeds by a Subsidiary of the Borrower, any amount required to be distributed to the holders of any minority equity interest in the respective Subsidiary (or in any other Subsidiary which directly or indirectly holds capital stock or equivalent interests in such Subsidiary), and (e) with respect to any sale, lease, transfer or other disposition of any asset, any amount of such Net Cash Proceeds set aside as a reserve established in good faith by the Borrower or such Subsidiary for indemnity or other potential claims in connection therewith until any unused reserves are no longer maintained in connection therewith, in each case to the extent, but only to the extent, that the amounts so deducted are at the time of receipt of such cash, actually paid to a Person that is not an Affiliate of the Borrower and are properly attributable to such transaction or to the asset that is the subject thereof, provided, that for purposes of determining the date of receipt of Net Cash Proceeds from the sale, lease, transfer or other disposition of any asset, such Net Cash Proceeds shall be deemed to have been received on the date that is six months after the date of such disposition.

“Northern Border” means Northern Border Pipeline Company, a Texas general partnership.

“Note” means a promissory note of the Borrower payable to the order of any Lender, delivered pursuant to a request made under Section 2.15 and in substantially the form of Exhibit A hereto, evidencing the aggregate indebtedness of the Borrower to such Lender resulting from the Advance made by such Lender.

“Notice of Borrowing” has the meaning specified in Section 2.02(a).

“Patriot Act” means the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001, Pub. L. 107-56, signed into law October 26, 2001.

“PBGC” means the Pension Benefit Guaranty Corporation (or any successor).

“Permitted Liens” means such of the following as to which no enforcement, collection, execution, levy or foreclosure proceeding shall have been commenced:  (a) Liens for taxes, assessments and governmental charges or levies to the extent not required to be paid under Section 5.01(b) hereof; (b) Liens imposed by law, such as materialmen’s, mechanics’, carriers’, workmen’s and repairmen’s Liens and other similar Liens arising in the ordinary course of business securing obligations that are not overdue for a period of more than 30 days unless being contested in good faith, provided that adequate reserves for the payment thereof have been established in accordance with GAAP and no property of the Borrower or any Subsidiary is subject to impending risk of loss or forfeiture by reason of nonpayment of the obligations

secured by such Liens; (c) pledges or deposits to secure obligations under workers’ compensation laws or similar legislation or to secure public or statutory obligations; and (d) easements, rights of way and other encumbrances on title to real property that do not render title to the property encumbered thereby unmarketable or materially adversely affect the use of such property for its present purposes.

“Person” means an individual, partnership, corporation (including a business trust), joint stock company, trust, unincorporated association, joint venture, limited liability company or other entity, or a government or any political subdivision or agency thereof.

“Plan” means a Single Employer Plan or a Multiple Employer Plan.

“Reference Banks” means CNAI, UBS Loan Finance LLC and Mizuho Corporate Bank, Ltd.

“Register” has the meaning specified in Section 8.07(d).

“Required Lenders” means at any time Lenders owed or holding at least a majority in interest of the Advances outstanding at such time or, if no Advances are then outstanding, Lenders holding at least a majority of the Commitments at such time.

“SEC” means the Securities and Exchange Commission, any successor thereto and any analogous governmental authority.

“Significant Subsidiary” has the meaning specified in Article 1, Rule 1-02(w) of Regulation S-X of the Securities Exchange Act of 1934 as of the Effective Date, provided, that, even if Northern Border and Tuscarora would not otherwise constitute a Subsidiary of the Borrower, each of Northern Border and Tuscarora shall be deemed to be a Significant Subsidiary of the Borrower if it would otherwise qualify as a Significant Subsidiary under Article 1, Rule 1-02(w) of Regulation S-X as of the Effective Date.

“Single Employer Plan” means a single employer plan, as defined in Section 4001(a)(15) of ERISA, that (a) is maintained for employees of the Borrower or any  ERISA Affiliate and no Person other than the Borrower and the ERISA Affiliates or (b) was so maintained and in respect of which the Borrower or any ERISA Affiliate could have liability under Section 4069 of ERISA in the event such plan has been or were to be terminated.

“Solvent” and “Solvency” mean, with respect to any Person on a particular date, that on such date (a) the fair value of the property of such Person is greater than the total amount of liabilities, including, without limitation, contingent liabilities, of such Person, (b) the present fair salable value of the assets of such Person is not less than the amount that will be required to pay the probable liability of such Person on its debts as they become absolute and matured, (c) such Person does not intend to, and does not believe that it will, incur debts or liabilities beyond such Person’s ability to pay such debts and liabilities as they mature and (d) such Person is not engaged in business or a transaction, and is not about to engage in business or a transaction, for which such Person’s property would constitute an unreasonably small capital. The amount of contingent liabilities at any time shall be computed as the amount that, in the light of all the facts and circumstances existing at such time, represents the amount that can reasonably be expected to become an actual or matured liability.

“Subsidiary” of any Person means any corporation, partnership, joint venture, limited liability company, trust or estate of which (or in which) more than 50% of (a) the issued and outstanding capital stock having ordinary voting power to elect a majority of the Board of Directors of such corporation (irrespective of whether at the time capital stock of any other class or classes of such corporation shall or might have voting power upon the occurrence of any contingency), (b) the interest in the capital or profits of such limited liability company, partnership or joint venture or (c) the beneficial interest in such trust or estate is at the time directly or indirectly owned or controlled by such Person, by such Person and one or more of its other Subsidiaries or by one or more of such Person’s other Subsidiaries.

“Termination Date” means the earlier of (a) March 31, 2008 and (b) the date of termination in whole of the Commitments pursuant to Section 2.04 or 6.01.

“Tuscarora” means Tuscarora Gas Transmission Company, a Nevada general partnership.

“Voting Stock” means capital stock issued by a corporation, or equivalent interests in any other Person, the holders of which are ordinarily, in the absence of contingencies, entitled to vote for the election of directors (or persons performing similar functions) of such Person, even if the right so to vote has been suspended by the happening of such a contingency.

SECTION 1.02.  Computation of Time Periods.  In this Agreement in the computation of periods of time from a specified date to a later specified date, the word “from” means “from and including” and the words “to” and “until” each mean “to but excluding”.

SECTION 1.03.  Accounting Terms.  All accounting terms not specifically defined herein shall be construed in accordance with generally accepted accounting principles consistent with those applied in the preparation of the financial statements referred to in Section 4.01(e) (“GAAP”). In the event that any Change in Accounting Principles shall occur and such change results in a change in the method of calculation of financial covenants, standards or terms in this Agreement, then, upon the request of the Borrower or the Required Lenders, the Borrower and the Agent agree to enter into negotiations in order to amend such provisions of this Agreement so as to reflect equitably such Change in Accounting Principles with the desired result that the criteria for evaluating the Borrower’s financial condition shall be the same after such Change in Accounting Principles as if such Change in Accounting Principles had not been made. Until such time as such an amendment shall have been executed and delivered by the Borrower, the Agent and the Required Lenders, all financial covenants, standards and terms in this Agreement shall continue to be calculated or construed as if such Change in Accounting Principles had not occurred.

ARTICLE II

AMOUNTS AND TERMS OF THE ADVANCES

SECTION 2.01.  The Advances.  Each Lender severally agrees, on the terms and conditions hereinafter set forth, to make an advance (its “Advance”) to the Borrower on the Effective Date in an amount not to exceed such Lender’s Commitment at such time. The Borrowing shall consist of Advances made simultaneously by the Lenders ratably according to their Commitments. Amounts borrowed under this Section 2.01 and repaid or prepaid may not be reborrowed.

SECTION 2.02.  Making the Advances.  (a)  Each Borrowing shall be made on notice, given not later than (x) 11:00 A.M. (New York City time) on the third Business Day prior to the date of the proposed Borrowing in the case of a Borrowing consisting of Eurodollar Rate Advances or (y) 11:00 A.M. (New York City time) on the date of the proposed Borrowing in the case of a Borrowing consisting of Base Rate Advances, by the Borrower to the Agent, which shall give to each Lender prompt notice thereof by telecopier. Each such notice of a Borrowing (a “Notice of Borrowing”) shall be by telephone, confirmed promptly in writing, or telecopier in substantially the form of Exhibit B hereto, specifying therein the requested (i) date of such Borrowing, (ii) Type of Advances comprising such Borrowing, (iii) aggregate amount of such Borrowing, and (iv) in the case of a Borrowing consisting of Eurodollar Rate Advances, initial Interest Period for each such Advance. Each Lender shall, before 1:00 P.M. (New York City time) on the date of such Borrowing, make available for the account of its Applicable Lending Office to the Agent at the Agent’s Account, in same day funds, such Lender’s ratable portion of such Borrowing. After the Agent’s receipt of such funds and upon fulfillment of the applicable conditions set forth in Article III, the Agent will make such funds available to the Borrower at the Agent’s address referred to in Section 8.02.

(b)           Anything in subsection (a) above to the contrary notwithstanding, (i) the Borrower may not select Eurodollar Rate Advances for any Borrowing if the aggregate amount of such Borrowing is less than $5,000,000 or if the obligation of the Lenders to make Eurodollar Rate Advances shall then be suspended pursuant

to Section 2.07 or 2.11 and (ii) the Eurodollar Rate Advances may not be outstanding as part of more than six separate Borrowings.

(c)           Each Notice of Borrowing shall be irrevocable and binding on the Borrower. In the case of any Borrowing that the related Notice of Borrowing specifies is to be comprised of Eurodollar Rate Advances, the Borrower shall indemnify each Lender as a result of any failure to fulfill on or before the date specified in such Notice of Borrowing for such Borrowing the applicable conditions set forth in Article III, including, without limitation, any loss (including loss of anticipated profits), cost or expense incurred by reason of the liquidation or reemployment of deposits or other acquired by such Lender to fund the Advance to be made by such Lender as part of such Borrowing when such Advance, as a result of such failure, is not made on such date.

(d)           Unless the Agent shall have received notice from a Lender prior to the time of any Borrowing that such Lender will not make available to the Agent such Lender’s ratable portion of such Borrowing, the Agent may assume that such Lender has made such portion available to the Agent on the date of such Borrowing in accordance with subsection (a) of this Section 2.02 and the Agent may, in reliance upon such assumption, make available to the Borrower on such date a corresponding amount. If and to the extent that such Lender shall not have so made such ratable portion available to the Agent, such Lender and the Borrower severally agree to repay to the Agent forthwith on demand such corresponding amount together with interest thereon, for each day from the date such amount is made available to the Borrower until the date such amount is repaid to the Agent, at (i) in the case of the Borrower, the interest rate applicable at the time to Advances comprising such Borrowing and (ii) in the case of such Lender, the Federal Funds Rate. If such Lender shall repay to the Agent such corresponding amount, such amount so repaid shall constitute such Lender’s Advance as part of such Borrowing for purposes of this Agreement.

(e)           The failure of any Lender to make the Advance to be made by it as part of any Borrowing shall not relieve any other Lender of its obligation, if any, hereunder to make its Advance on the date of such Borrowing, but no Lender shall be responsible for the failure of any other Lender to make the Advance to be made by such other Lender on the date of any Borrowing.

SECTION 2.03.  Fees.  (a)  Commitment Fee. The Borrower agrees to pay to the Agent for the account of each Lender a commitment fee on the aggregate amount of such Lender’s unused Commitment from the date hereof until the Effective Date at a rate per annum equal to the Applicable Percentage in effect from time to time, payable in arrears quarterly on the last day of each March, June, September and December, commencing June 30, 2006, and on the Effective Date.

(b)           Agent’s Fees. The Borrower shall pay to the Agent for its own account such fees as may from time to time be agreed between the Borrower and the Agent.

SECTION 2.04.  Termination or Reduction of the Commitments.  (a)  Optional. The Borrower shall have the right, upon at least three Business Days’ notice to the Agent, to terminate in whole or permanently reduce ratably in part the unused portions of the Commitments, provided that each partial reduction shall be in the aggregate amount of $1,000,000 or an integral multiple of $1,000,000 in excess thereof .

(b)           Mandatory. On the Effective Date, after giving effect to any Borrowing made on such date, and from time to time thereafter upon prepayment of the Advances, the aggregate Commitments shall be automatically and permanently reduced, on a pro rata basis, by an amount equal to the amount by which (i) the aggregate Commitments immediately prior to such reduction exceed (ii) the aggregate unpaid principal amount of the Advances then outstanding.

SECTION 2.05.  Repayment.  The Borrower shall repay to the Agent for the ratable account of the Lenders on the Maturity Date the aggregate principal amount of the Advances then outstanding.

SECTION 2.06.  Interest on Advances.  (a)  Scheduled Interest. The Borrower shall pay interest on the unpaid principal amount of each Advance owing to each Lender from the date of such Advance until such principal amount shall be paid in full, at the following rates per annum:

(i)            Base Rate Advances. During such periods as such Advance is a Base Rate Advance, a rate per annum equal at all times to the sum of (x) the Base Rate in effect from time to time plus (y) the Applicable Margin in effect from time to time, payable in arrears quarterly on the last day of each March, June, September and December during such periods and on the date such Base Rate Advance shall be Converted or paid in full.

(ii)           Eurodollar Rate Advances. During such periods as such Advance is a Eurodollar Rate Advance, a rate per annum equal at all times during each Interest Period for such Advance to the sum of (x) the Eurodollar Rate for such Interest Period for such Advance plus (y) the Applicable Margin in effect from time to time, payable in arrears on the last day of such Interest Period and, if such Interest Period has a duration of more than three months, on each day that occurs during such Interest Period every three months from the first day of such Interest Period and on the date such Eurodollar Rate Advance shall be Converted or paid in full.

(b)           Default Interest. Upon the occurrence and during the continuance of an Event of Default under Section 6.01(a), the Agent may, and upon the request of the Required Lenders shall, require the Borrower to pay interest (“Default Interest”) on (i) the unpaid principal amount of each Advance owing to each Lender, payable in arrears on the dates referred to in clause (a)(i) or (a)(ii) above, at a rate per annum equal at all times to 2% per annum above the rate per annum required to be paid on such Advance pursuant to clause (a)(i) or (a)(ii) above and (ii) to the fullest extent permitted by law, the amount of any interest, fee or other amount payable hereunder that is not paid when due, from the date such amount shall be due until such amount shall be paid in full, payable in arrears on the date such amount shall be paid in full and on demand, at a rate per annum equal at all times to 2% per annum above the rate per annum required to be paid on Base Rate Advances pursuant to clause (a)(i) above, provided, however, that following acceleration of the Advances pursuant to Section 6.01, Default Interest shall accrue and be payable hereunder whether or not previously required by the Agent.

SECTION 2.07.  Interest Rate Determination.  (a)  Each Reference Bank agrees to furnish to the Agent timely information for the purpose of determining each Eurodollar Rate. If any one or more of the Reference Banks shall not furnish such timely information to the Agent for the purpose of determining any such interest rate, the Agent shall determine such interest rate on the basis of timely information furnished by the remaining Reference Banks. The Agent shall give prompt notice to the Borrower and the Lenders of the applicable interest rate determined by the Agent for purposes of Section 2.06(a)(i) or (ii), and the rate, if any, furnished by each Reference Bank for the purpose of determining the interest rate under Section 2.06(a)(ii).

(b)           If, with respect to any Eurodollar Rate Advances, the Required Lenders notify the Agent that the Eurodollar Rate for any Interest Period for such Advances will not adequately reflect the cost to such Required Lenders of making, funding or maintaining their respective Eurodollar Rate Advances for such Interest Period, the Agent shall forthwith so notify the Borrower and the Lenders, whereupon (i) each Eurodollar Rate Advance will automatically, on the last day of the then existing Interest Period therefor, Convert into a Base Rate Advance, and (ii) the obligation of the Lenders to make, or to Convert Advances into, Eurodollar Rate Advances shall be suspended until the Agent shall notify the Borrower that such Lenders have determined that the circumstances causing such suspension no longer exist.

(c)           If the Borrower shall fail to select the duration of any Interest Period for any Eurodollar Rate Advances in accordance with the provisions contained in the definition of “Interest Period” in Section 1.01, the Agent will forthwith so notify the Borrower and the Lenders and such Advances will automatically, on the last day of the then existing Interest Period therefor, Convert into a Eurodollar Rate Borrowing having an Interest Period of one month.

(d)           On the date on which the aggregate unpaid principal amount of Eurodollar Rate Advances comprising any Borrowing shall be reduced, by payment or prepayment or otherwise, to less than $1,000,000, such Advances shall automatically Convert into Base Rate Advances.

(e)           Upon the occurrence and during the continuance of any Event of Default, (i) each Eurodollar Rate Advance will automatically, on the last day of the then existing Interest Period therefor, Convert

into a Base Rate Advance and (ii) the obligation of the Lenders to make, or to Convert Advances into, Eurodollar Rate Advances shall be suspended.

(f)            If Moneyline Telerate Markets Page 3750 is unavailable and fewer than two Reference Banks furnish timely information to the Agent for determining the Eurodollar Rate for any Eurodollar Rate Advances,

(i)            the Agent shall forthwith notify the Borrower and the Lenders that the interest rate cannot be determined for such Eurodollar Rate Advances,

(ii)           each such Advance will automatically, on the last day of the then existing Interest Period therefor, Convert into a Base Rate Advance (or if such Advance is then a Base Rate Advance, will continue as a Base Rate Advance), and

(iii)          the obligation of the Lenders to make Eurodollar Rate Advances or to Convert Advances into Eurodollar Rate Advances shall be suspended until the Agent shall notify the Borrower and the Lenders that the circumstances causing such suspension no longer exist.

SECTION 2.08.  Optional Conversion of Advances.  The Borrower may on any Business Day, upon notice given to the Agent not later than 11:00 A.M. (New York City time) on the third Business Day prior to the date of the proposed Conversion and subject to the provisions of Sections 2.07 and 2.11, Convert all or any portion of Advances of one Type comprising the same Borrowing into Advances of the other Type; provided, however, that any Conversion of Base Rate Advances into Eurodollar Rate Advances shall be in an amount not less than the minimum amount specified in Section 2.02(b), no Conversion of any Advances shall result in more separate Borrowings than permitted under Section 2.02(b) and each Conversion of Advances comprising part of the same Borrowing shall be made ratably among the Lenders in accordance with their Commitments and provided, further that for any Conversion of Eurodollar Rate Advances into Base Rate Advances made other than on the last day of an Interest Period for such Eurodollar Rate Advances the Borrower shall be obligated to reimburse the Lenders in respect thereof pursuant to Section 8.04(c). Each such notice of a Conversion shall, within the restrictions specified above, specify (i) the date of such Conversion, (ii) the Advances to be Converted, and (iii) if such Conversion is into Eurodollar Rate Advances, the duration of the initial Interest Period for each such Advance. Each notice of Conversion shall be irrevocable and binding on the Borrower.

SECTION 2.09.  Prepayments of Advances.  The Borrower may, upon notice at least two Business Days’ prior to the date of such prepayment, in the case of Eurodollar Rate Advances, and not later than 11:00 A.M. (New York City time) on the date of such prepayment, in the case of Base Rate Advances, to the Agent stating the proposed date and aggregate principal amount of the prepayment, and if such notice is given the Borrower shall, prepay the outstanding principal amount of the Advances comprising part of the same Borrowing in whole or ratably in part, together with accrued interest to the date of such prepayment on the principal amount prepaid; provided, however, that (x) each partial prepayment shall be in an aggregate principal amount of $10,000,000 or an integral multiple of $1,000,000 in excess thereof  and (y) in the event of any such prepayment of a Eurodollar Rate Advance made other than on the last day of an Interest Period for such Eurodollar Rate Advances, the Borrower shall be obligated to reimburse the Lenders in respect thereof pursuant to Section 8.04(c).

(b)           Mandatory. (i)  If the Borrower and its Subsidiaries shall have received Net Cash Proceeds in excess of $10,000,000 from (A) the sale, lease, transfer or other disposition of any assets of the Borrower (other than any sale, lease, transfer or other disposition of assets (1) in the ordinary course of business or (2) to the extent that the Net Cash Proceeds thereof are reinvested in similar assets within six months after the receipt of such Net Cash Proceeds), (B) the incurrence of or issuance by the Borrower or any of its Subsidiaries of any indebtedness for borrowed money, including indebtedness evidenced by notes, bonds, debentures or other similar instruments or (C) the sale or issuance by the Borrower of any of its equity interests, the Borrower shall be required to make a mandatory prepayment of Advances comprising a part of the same Borrowings in an aggregate amount equal to such Net Cash Proceeds. Any mandatory prepayment of Advances required to be made pursuant to this Section 2.09(b) shall be made on the earlier of (1) the last day of the Interest Period for any Advance ending after the date of receipt of such Net Cash Proceeds (until all such Net Cash Proceeds have been prepaid) and (2) the

30^th calendar day after the receipt thereof; provided, that, all such Net Cash Proceeds shall have been applied to prepay Advances not later than the 30^th calendar day after the date that such Net Cash Proceeds exceed $10,000,000.

(ii)           Each prepayment made pursuant to this Section 2.09(b) shall be made together with any interest accrued to the date of such prepayment on the principal amounts prepaid and, in the case of any prepayment of a Eurodollar Rate Advance on a date other than the last day of an Interest Period or at its maturity, any additional amounts which the Borrower shall be obligated to reimburse to the Lenders in respect thereof pursuant to Section 8.04(c).

SECTION 2.10.  Increased Costs.  (a)  If, due to either (i) the introduction of or any change in or in the interpretation of any law or regulation after the Effective Date or (ii) the compliance with any guideline or request adopted after the Effective Date from any central bank or other governmental authority (whether or not having the force of law), there shall be any increase in the cost to any Lender of agreeing to make or making, funding or maintaining Eurodollar Rate Advances (excluding for purposes of this Section 2.10 any  such increased costs resulting from (i) Taxes or Other Taxes (as to which Section 2.13 shall govern) and (ii) changes in the basis of taxation of overall net income or overall gross income by the United States or by the foreign jurisdiction or state under the laws of which such Lender is organized or has its Applicable Lending Office or any political subdivision thereof), then the Borrower shall from time to time, upon demand by such Lender (with a copy of such demand to the Agent), pay to the Agent for the account of such Lender additional amounts sufficient to compensate such Lender for such increased cost. A certificate as to the amount of such increased cost, submitted to the Borrower and the Agent by such Lender, shall be conclusive and binding for all purposes, absent manifest error.

(b)           If any Lender determines that compliance with any law or regulation or any guideline or request from any central bank or other governmental authority (whether or not having the force of law) adopted or issued after the Effective Date affects or would affect the amount of capital required or expected to be maintained by such Lender or any corporation controlling such Lender and that the amount of such capital is increased by or based upon the existence of such Lender’s commitment to lend hereunder and other commitments of this type, then, upon demand by such Lender (with a copy of such demand to the Agent), the Borrower shall pay to the Agent for the account of such Lender, from time to time as specified by such Lender, additional amounts sufficient to compensate such Lender or such corporation in the light of such circumstances, to the extent that such Lender reasonably determines such increase in capital to be allocable to the existence of such Lender’s commitment to lend hereunder. A certificate as to such amounts submitted to the Borrower and the Agent by such Lender shall be conclusive and binding for all purposes, absent manifest error.

(c)           Notwithstanding anything to the contrary in this Section 2.10, the Borrower shall not be required to compensate a Lender pursuant to this Section 2.10 for any amounts incurred more than six months prior to the date that such Lender notifies the Borrower of such Lender’s intention to claim compensation therefor; provided that, if the circumstances giving rise to such claim have a retroactive effect, then such six-month period shall be extended to include the period of such retroactive effect.

SECTION 2.11.  Illegality.  Notwithstanding any other provision of this Agreement, if any Lender shall notify the Agent that the introduction of or any change in or in the interpretation of any law or regulation makes it unlawful, or any central bank or other governmental authority asserts that it is unlawful, for any Lender or its Eurodollar Lending Office to perform its obligations hereunder to make Eurodollar Rate Advances or to fund or maintain Eurodollar Rate Advances hereunder, (a) each Eurodollar Rate Advance will automatically, upon the last day of the applicable Interest Period or, if required by applicable law, immediately upon such demand, Convert into a Base Rate Advance and (b) the obligation of the Lenders to make Eurodollar Rate Advances or to Convert Advances into Eurodollar Rate Advances shall be suspended until the Agent shall notify the Borrower that such Lender has determined that the circumstances causing such suspension no longer exist.

SECTION 2.12.  Payments and Computations.  (a)  The Borrower shall make each payment hereunder, irrespective of any right of counterclaim or set-off,  not later than 11:00 A.M. (New York City time) on the day when due in U.S. dollars to the Agent at the Agent’s Account in same day funds. The Agent will promptly thereafter cause to be distributed like funds relating to the payment of principal or interest or fees ratably (other than amounts payable pursuant to Section 2.10, 2.13 or 8.04(c)) to the Lenders for the account of their respective Applicable Lending Offices, and like funds relating to the payment of any other amount payable to any Lender to

such Lender for the account of its Applicable Lending Office, in each case to be applied in accordance with the terms of this Agreement. Upon its acceptance of an Assignment and Acceptance and recording of the information contained therein in the Register pursuant to Section 8.07(c), from and after the effective date specified in such Assignment and Acceptance, the Agent shall make all payments hereunder and under the Notes in respect of the interest assigned thereby to the Lender assignee thereunder, and the parties to such Assignment and Acceptance shall make all appropriate adjustments in such payments for periods prior to such effective date directly between themselves.

(b)           The Borrower hereby authorizes each Lender, if and to the extent payment owed to such Lender is not made when due hereunder or under the Note held by such Lender, to charge from time to time against any or all of the Borrower’s accounts with such Lender any amount so due.

(c)           All computations of interest based on the Base Rate shall be made by the Agent on the basis of a year of 365 or 366 days, as the case may be, and all computations of interest based on the Eurodollar Rate or the Federal Funds Rate and of fees shall be made by the Agent on the basis of a year of 360 days, in each case for the actual number of days (including the first day but excluding the last day) occurring in the period for which such interest or fees are payable. Each determination by the Agent of an interest rate hereunder shall be conclusive and binding for all purposes, absent manifest error.

(d)           Whenever any payment hereunder or under the Notes shall be stated to be due on a day other than a Business Day, such payment shall be made on the next succeeding Business Day, and such extension of time shall in such case be included in the computation of payment of interest or fee, as the case may be; provided, however, that, if such extension would cause payment of interest on or principal of Eurodollar Rate Advances to be made in the next following calendar month, such payment shall be made on the next preceding Business Day.

(e)           Unless the Agent shall have received notice from the Borrower prior to the date on which any payment is due to the Lenders hereunder that the Borrower will not make such payment in full, the Agent may assume that the Borrower has made such payment in full to the Agent on such date and the Agent may, in reliance upon such assumption, cause to be distributed to each Lender on such due date an amount equal to the amount then due such Lender. If and to the extent the Borrower shall not have so made such payment in full to the Agent, each Lender shall repay to the Agent forthwith on demand such amount distributed to such Lender together with interest thereon, for each day from the date such amount is distributed to such Lender until the date such Lender repays such amount to the Agent, at the Federal Funds Rate.

SECTION 2.13.  Taxes.  (a)  Any and all payments by the Borrower to or for the account of any Lender or the Agent hereunder or under the Notes or any other documents to be delivered hereunder shall be made, in accordance with Section 2.12 or the applicable provisions of such other documents, free and clear of and without deduction for any and all present or future taxes, levies, imposts, deductions, charges or withholdings, and all liabilities with respect thereto, excluding, in the case of each Lender and the Agent, any branch profits tax imposed by the United States and taxes imposed on its overall net income, and franchise taxes imposed on it in lieu of net income taxes, by the jurisdiction under the laws of which such Lender or the Agent (as the case may be) is organized or any political subdivision thereof and, in the case of each Lender, taxes imposed on its overall net income, and franchise taxes imposed on it in lieu of net income taxes, by the jurisdiction of such Lender’s Applicable Lending Office or any political subdivision thereof (all such non-excluded taxes, levies, imposts, deductions, charges, withholdings and liabilities in respect of payments hereunder or under the Notes being hereinafter referred to as “Taxes”). If the Borrower shall be required by law to deduct any Taxes from or in respect of any sum payable hereunder or under any Note or any other documents to be delivered hereunder to any Lender or the Agent, (i) the sum payable shall be increased as may be necessary so that after making all required deductions (including deductions applicable to additional sums payable under this Section 2.13) such Lender or the Agent (as the case may be) receives an amount equal to the sum it would have received had no such deductions been made, (ii) the Borrower shall make such deductions and (iii) the Borrower shall pay the full amount deducted to the relevant taxation authority or other authority in accordance with applicable law.

(b)           In addition, the Borrower shall pay any present or future stamp or documentary taxes or any other excise or property taxes, charges or similar levies that arise from any payment made hereunder or under the Notes or any other documents to be delivered hereunder or from the execution, delivery or registration of,

performing under, or otherwise with respect to, this Agreement or the Notes or any other documents to be delivered hereunder (hereinafter referred to as “Other Taxes”).

(c)           The Borrower shall indemnify each Lender and the Agent for and hold it harmless against the full amount of Taxes or Other Taxes (including, without limitation, taxes of any kind imposed or asserted by any jurisdiction on amounts payable under this Section 2.13) imposed on or paid by such Lender or the Agent (as the case may be) and any liability (including penalties, interest and expenses) arising therefrom or with respect thereto. This indemnification shall be made within 30 days from the date such Lender or the Agent (as the case may be) makes written demand therefor.

(d)           Within 30 days after the date of any payment of Taxes, the Borrower shall furnish to the Agent, at its address referred to in Section 8.02, the original or a certified copy of a receipt evidencing such payment to the extent such a receipt is issued therefor, or other written proof of payment thereof that is reasonably satisfactory to the Agent. In the case of any payment hereunder or under the Notes or any other documents to be delivered hereunder by or on behalf of the Borrower through an account or branch outside the United States or by or on behalf of the Borrower by a payor that is not a United States person, if the Borrower determines that no Taxes are payable in respect thereof, the Borrower shall furnish, or shall cause such payor to furnish, to the Agent, at such address, an opinion of counsel acceptable to the Agent stating that such payment is exempt from Taxes. For purposes of this subsection (d) and subsection (e), the terms “United States” and “United States person” shall have the meanings specified in Section 7701 of the Internal Revenue Code.

(e)           Each Lender organized under the laws of a jurisdiction outside the United States, on or prior to the date of its execution and delivery of this Agreement in the case of each Initial Lender and on the date of the Assignment and Acceptance pursuant to which it becomes a Lender in the case of each other Lender, and from time to time thereafter as reasonably requested in writing by the Borrower (but only so long as such Lender remains lawfully able to do so), shall provide each of the Agent and the Borrower with two original Internal Revenue Service Forms W-8BEN or W-8ECI, as appropriate, or any successor or other form prescribed by the Internal Revenue Service, certifying that such Lender is exempt from or entitled to a reduced rate of United States withholding tax on payments pursuant to this Agreement or the Notes and, in the case of any Lender claiming the benefits of the exemption for portfolio interest under section 881(c) of the Internal Revenue Code, a certificate to the effect that such Lender is not (A) a “bank” described in section 881(c)(3)(A) of the Internal Revenue Code, (B) a “10 percent shareholder” of the Borrower described in section 881(c)(3)(B) of the Internal Revenue Code, or (C) a “controlled foreign corporation” described in section 881(c)(3)(C) of the Internal Revenue Code. Each such Lender shall promptly notify the Borrower at any time it determines that it is no longer in a position to provide any previously delivered certificate to the Borrower (or any other form of certification adopted by the U.S. taxing authorities for such purpose). If the form provided by a Lender at the time such Lender first becomes a party to this Agreement indicates a United States interest withholding tax rate in excess of zero, withholding tax at such rate shall be considered excluded from Taxes unless and until such Lender provides the appropriate forms certifying that a lesser rate applies, whereupon withholding tax at such lesser rate only shall be considered excluded from Taxes for periods governed by such form; provided, however, that, if at the date of the Assignment and Acceptance pursuant to which a Lender assignee becomes a party to this Agreement, the Lender assignor was entitled to payments under subsection (a) in respect of United States withholding tax with respect to interest paid at such date, then, to such extent, the term Taxes shall include (in addition to withholding taxes that may be imposed in the future or other amounts otherwise includable in Taxes) United States withholding tax, if any, applicable with respect to the Lender assignee on such date. If any form or document referred to in this subsection (e) requires the disclosure of information, other than information necessary to compute the tax payable and information required on the date hereof by Internal Revenue Service Form W-8BEN or W-8ECI, that the Lender reasonably considers to be confidential, the Lender shall give notice thereof to the Borrower and shall not be obligated to include in such form or document such confidential information. If requested by the Borrower in order to obtain an exemption from or reduction from non-U.S. withholding taxes, a Lender shall deliver to the Borrower (with a copy to the Agent) at the time or times prescribed by applicable law, such properly completed and executed documentation prescribed by applicable law as will permit such payments to be made without withholding or at a reduced rate, provided that such Lender is legally entitled to complete, execute and deliver such documentation and in such Lender’s judgment such completion, execution or submission would not materially prejudice the legal position of such Lender.

(f)            For any period with respect to which a Lender has failed to provide the Borrower with the appropriate form, certificate or other document described in Section 2.13(e) (other than if such failure is due to a change in law, or in the interpretation or application thereof, occurring subsequent to the date on which a form, certificate or other document originally was required to be provided, or if such form, certificate or other document otherwise is not required under subsection (e) above), such Lender shall not be entitled to the additional payment or indemnification under Section 2.13(a) or (c) with respect to Taxes imposed by the United States by reason of such failure; provided, however, that should a Lender become subject to Taxes because of its failure to deliver a form, certificate or other document required hereunder, the Borrower shall take such steps as the Lender shall reasonably request to assist the Lender to recover such Taxes.

(g)           If the Agent or any Lender determines, in its sole discretion, that it has received a refund of any Taxes or Other Taxes as to which it has been indemnified by the Borrower or with respect to which the Borrower has paid amounts pursuant to this Section 2.13, it shall pay over such refund to the Borrower (but only to the extent of indemnity payments made, or additional amounts paid, by the Borrower under this Section 2.13 with respect to the Taxes or Other Taxes giving rise to such refund), net of all out-of-pocket expenses of the Agent or such Lender and without interest (other than any interest paid by the relevant governmental authority with respect to such refund); provided, that the Borrower, upon the request of the Agent or such Lender, agrees to repay the amount paid over to the Borrower (plus any penalties, interest or other charges imposed by the relevant governmental authority) to the Agent or such Lender in the event the Agent or such Lender is required to repay such refund to such governmental authority. This paragraph shall not be construed to require the Agent or any Lender to make available its tax returns (or any other information relating to its taxes which it deems confidential) to the Borrower or any other Person.

SECTION 2.14.  Sharing of Payments, Etc.  If any Lender shall obtain any payment (whether voluntary, involuntary, through the exercise of any right of set-off, or otherwise) on account of the Advances owing to it (other than pursuant to Section 2.10, 2.13 or 8.04(c)) in excess of its ratable share of payments on account of the Advances obtained by all the Lenders, such Lender shall forthwith purchase from the other Lenders such participations in the Advances owing to them as shall be necessary to cause such purchasing Lender to share the excess payment ratably with each of them; provided, however, that if all or any portion of such excess payment is thereafter recovered from such purchasing Lender, such purchase from each Lender shall be rescinded and such Lender shall repay to the purchasing Lender the purchase price to the extent of such recovery together with an amount equal to such Lender’s ratable share (according to the proportion of (i) the amount of such Lender’s required repayment to (ii) the total amount so recovered from the purchasing Lender) of any interest or other amount paid or payable by the purchasing Lender in respect of the total amount so recovered. The Borrower agrees that any Lender so purchasing a participation from another Lender pursuant to this Section 2.14 may, to the fullest extent permitted by law, exercise all its rights of payment (including the right of set-off) with respect to such participation as fully as if such Lender were the direct creditor of the Borrower in the amount of such participation.

SECTION 2.15.  Evidence of Debt.  (a)  Each Lender shall maintain in accordance with its usual practice an account or accounts evidencing the indebtedness of the Borrower to such Lender resulting from each Advance owing to such Lender from time to time, including the amounts of principal and interest payable and paid to such Lender from time to time hereunder in respect of Advances. The Borrower agrees that upon notice by any Lender to the Borrower (with a copy of such notice to the Agent) to the effect that a Note is required or appropriate in order for such Lender to evidence (whether for purposes of pledge, enforcement or otherwise) the Advances owing to, or to be made by, such Lender, the Borrower shall promptly execute and deliver to such Lender a Note, in substantially the form of Exhibit A hereto, respectively, payable to the order of such Lender in a principal amount equal to the Commitment of such Lender.

(b)           The Register maintained by the Agent pursuant to Section 8.07(d) shall include a control account, and a subsidiary account for each Lender, in which accounts (taken together) shall be recorded (i) the date and amount of each Borrowing made hereunder, the Type of Advances comprising such Borrowing and, if appropriate, the Interest Period applicable thereto, (ii) the terms of each Assignment and Acceptance delivered to and accepted by it, (iii) the amount of any principal or interest due and payable or to become due and payable from the Borrower to each Lender hereunder and (iv) the amount of any sum received by the Agent from the Borrower hereunder and each Lender’s share thereof.

(c)           Entries made in good faith by the Agent in the Register pursuant to subsection (b) above, and by each Lender in its account or accounts pursuant to subsection (a) above, shall be prima facie evidence of the amount of principal and interest due and payable or to become due and payable from the Borrower to, in the case of the Register, each Lender and, in the case of such account or accounts, such Lender, under this Agreement, absent manifest error; provided, however, that the failure of the Agent or such Lender to make an entry, or any finding that an entry is incorrect, in the Register or such account or accounts shall not limit or otherwise affect the obligations of the Borrower under this Agreement.

SECTION 2.16.  Use of Proceeds.  The proceeds of the Advances shall be available (and the Borrower agrees that it shall use such proceeds) solely for payment of the cash consideration of the Acquisition and the transaction fee related to the Acquisition.

SECTION 2.17  Change of Lending Office.  Each Lender agrees that, upon the occurrence of any event giving rise to the operation of Section 2.10 or 2.13(a) with respect to such Lender, it will, if requested by the Borrower, use reasonable efforts (consistent with its internal policy and legal and regulatory restrictions) to designate another lending office for any Advances affected by such event with the object of avoiding the consequences of such event; provided, that such designation would not, in the reasonable judgment of such Lender, be otherwise disadvantageous to such Lender, and provided, further, that nothing in this Section 2.18 shall affect or postpone any of the obligations of the Borrower or the rights of any Lender pursuant to Section 2.10 or 2.13(a).

ARTICLE III

CONDITIONS TO EFFECTIVENESS AND LENDING

SECTION 3.01.  Conditions Precedent to Effectiveness of Section 2.01.  Section 2.01 of this Agreement shall become effective on and as of the first date (the “Effective Date”) on which the following conditions precedent have been satisfied:

(a)           There shall have occurred no Material Adverse Change since December 31, 2005.

(b)           There shall exist no action, suit, investigation, litigation or proceeding affecting the General Partner, the Borrower or any of its Subsidiaries pending or threatened before any court, governmental agency or arbitrator that (i) would be reasonably likely to have a Material Adverse Effect other than the matters described on Schedule 3.01(b) hereto (the “Disclosed Litigation”) or (ii) purports to affect the legality, validity or enforceability of this Agreement or any Note or the consummation of the transactions contemplated hereby, and there shall have been no adverse change in the status, or financial effect on the Borrower or any of its Subsidiaries, of the Disclosed Litigation from that described on Schedule 3.01(b) hereto.

(c)           Nothing shall have come to the attention of the Lenders during the course of their due diligence investigation to lead them to believe that the Information Memorandum was or has become misleading, incorrect or incomplete in any material respect; without limiting the generality of the foregoing, the Lenders shall have been given such access to the management, records, books of account, contracts and properties of the Borrower and its Subsidiaries as they shall have reasonably requested.

(d)           All governmental and third party consents and approvals necessary in connection with the transactions contemplated hereby  and the Acquisition shall have been obtained (without the imposition of any conditions that are not acceptable to the Lenders) and shall remain in effect, and no law or regulation shall be applicable in the reasonable judgment of the Lenders that restrains, prevents or imposes materially adverse conditions upon the transactions contemplated hereby.

(e)           The Borrower shall have notified each Lender and the Agent in writing as to the proposed Effective Date.

(f)            The Borrower shall have paid all accrued fees and expenses of the Agent and the Lenders (including the accrued reasonable  fees and expenses of counsel to the Agent).

(g)           On the Effective Date, the following statements shall be true and the Agent shall have received for the account of each Lender a certificate of the Borrower, or on its behalf by the General Partner of the Borrower, signed on behalf of such Person by its President or a Vice President and its Secretary or any Assistant Secretary (or persons performing similar functions), dated the Effective Date, stating that:

(i)            The representations and warranties contained in Section 4.01 are correct on and as of the Effective Date,

(ii)           No event has occurred and is continuing that constitutes a Default,

(iii)          All governmental and third party consents and approvals necessary in connection with the transactions contemplated hereby have been obtained (without the imposition of any conditions that are not acceptable to the Lenders) and shall remain in effect, all applicable waiting periods in connection with the Acquisition shall have expired without any action being taken by any competent authority, and no law or regulation shall be applicable in the reasonable judgment of the Lenders, in each case that restrains, prevents or imposes materially adverse conditions upon the transactions contemplated hereby, and

(iv)          All conditions precedent to the consummation of the Acquisition (other than the payment of cash consideration from, among other sources, the proceeds of the initial Borrowing hereunder) have been satisfied substantially in accordance with the terms of the Partnership Interest Purchase and Sale Agreement dated as of December 31, 2005 between Northern Border Intermediate Limited Partnership, a Delaware limited partnership, and TC PipeLines Intermediate Limited Partnership, a Delaware limited partnership, without any waiver or amendment not consented to by the Required Lenders of any material term, provision or condition set forth therein, and in compliance with all applicable laws.

(h)           The Agent shall have received on or before the Effective Date the following, each dated such day, in form and substance satisfactory to the Agent and (except for the Notes) in sufficient copies for each Lender:

(i)            The Notes to the order of the Lenders to the extent requested by any Lender pursuant to Section 2.15.

(ii)           Certified copies of the resolutions of or on behalf of the Borrower approving this Agreement and the Notes, and/or authorizing the General Partner or officers, as applicable, to act on behalf of the Borrower, and of all documents evidencing other necessary action (including, without limitation, all necessary General Partner, board of directors or other similar action) and governmental and other third party approvals and consents, if any, with respect to this Agreement and the Notes.

(iii)          A certificate of the Secretary or an Assistant Secretary of the General Partner of the Borrower certifying the names and true signatures of the officers of such Person authorized to sign this Agreement and the Notes and the other documents to be delivered hereunder.

(iv)          A favorable opinion of Orrick, Herrington & Sutcliffe LLP, counsel for the Borrower, substantially in the form of Exhibit D hereto and as to such other matters as any Lender through the Agent may reasonably request.

(v)           A favorable opinion of Shearman & Sterling LLP, counsel for the Agent, in form and substance satisfactory to the Agent.

SECTION 3.02.  Conditions Precedent to Each Borrowing.  The obligation of each Lender to make an Advance on the occasion of each Borrowing shall be subject to the conditions precedent that the Effective Date shall have occurred and on the date of such Borrowing (a) the following statements shall be true (and each of the giving of the applicable Notice of Borrowing and the acceptance by the Borrower of the proceeds of such Borrowing shall constitute a representation and warranty by the Borrower that on the date of such Borrowing such statements are true):

(i)            the representations and warranties contained in Section 4.01 (other than the representation set forth in Section 4.01(f)) are correct on and as of such date, before and after giving effect to such Borrowing, and to the application of the proceeds therefrom, as though made on and as of such date, and

(ii)           no event has occurred and is continuing, or would result from such Borrowing or from the application of the proceeds therefrom, that constitutes a Default;

and (b) the Agent shall have received such other approvals, opinions or documents as any Lender through the Agent may reasonably request.

SECTION 3.03.  Determinations Under Section 3.01.  For purposes of determining compliance with the conditions specified in Section 3.01, each Lender shall be deemed to have consented to, approved or accepted or to be satisfied with each document or other matter required thereunder to be consented to or approved by or acceptable or satisfactory to the Lenders unless an officer of the Agent responsible for the transactions contemplated by this Agreement shall have received notice from such Lender prior to the date that the Borrower, by notice to the Lenders, designates as the proposed Effective Date, specifying its objection thereto. The Agent shall promptly notify the Lenders of the occurrence of the Effective Date.

ARTICLE IV

REPRESENTATIONS AND WARRANTIES

SECTION 4.01.  Representations and Warranties of the Borrower.  The Borrower represents and warrants as follows:

(a)           The Borrower is a limited partnership duly organized, validly existing and in good standing under the laws of the State of Delaware. The General Partner is a corporation duly organized, validly existing and in good standing under the laws of the State of Delaware.

(b)           The execution, delivery and performance by the Borrower of this Agreement and the Notes to be delivered by it, and the consummation of the transactions contemplated hereby, are within the Borrower’s partnership or the General Partner’s general corporate powers, have been duly authorized by all necessary action by or on behalf of the General Partner or the Borrower (including, without limitation, all necessary partner, managing member or other similar action), and do not contravene (i) the Borrower’s or the General Partner’s organizational documents or (ii) any material law or any material contractual restriction binding on or affecting the Borrower.

(c)           No material authorization or approval or other action by, and no notice to or filing with, any governmental authority or regulatory body or any other third party is required for the due execution, delivery and performance by the Borrower or any general partner or managing member of the Borrower of this Agreement or the Notes to be delivered by it.

(d)           This Agreement has been, and each of the Notes to be delivered by it when delivered hereunder will have been, duly executed and delivered by the Borrower. This Agreement is, and each of the Notes when delivered hereunder will be, the legal, valid and binding obligation of the Borrower enforceable against the Borrower in accordance with their respective terms, except as enforceability may be limited by applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the enforcement of creditors’ rights generally and by general equitable principles (whether enforcement is sought by proceedings in equity or at law).

(e)           The Consolidated balance sheet of the Borrower and its Subsidiaries as at December 31, 2005, and the related Consolidated statements of comprehensive income and cash flows of the Borrower and its Subsidiaries for the fiscal year then ended, accompanied by an opinion of KPMG LLP, independent public accountants, copies of which have been furnished to each Lender, fairly present the Consolidated financial condition of the Borrower and its Subsidiaries as at such date and the Consolidated results of the operations of the Borrower and its Subsidiaries for the period ended on such date, all in accordance with generally accepted accounting principles in the United States of America consistently applied.

(f)            Since December 31, 2005, there has been no Material Adverse Change.

(g)           There is no pending or, to the knowledge of the Borrower, threatened action, suit, investigation, litigation or proceeding, including, without limitation, any Environmental Action, against the General Partner, the Borrower or any of its Subsidiaries (other than the Disclosed Litigation) before any court, governmental agency or arbitrator that (i) is reasonably likely to have a Material Adverse Effect or (ii) purports to affect the legality, validity or enforceability of this Agreement or any Note or the consummation of the transactions contemplated hereby.

(h)           The Borrower is not engaged in the business of extending credit for the purpose of purchasing or carrying margin stock (within the meaning of Regulation U issued by the Board of Governors of the Federal Reserve System), and no proceeds of any Advance will be used to purchase or carry any margin stock or to extend credit to others for the purpose of purchasing or carrying any margin stock.

(i)            The Borrower is not an “investment company”, or a company “controlled” by an “investment company”, within the meaning of the Investment Company Act of 1940, as amended.

(j)            Neither the Information Memorandum nor any other information, exhibit or report furnished by or on behalf of the Borrower to the Agent or any Lender in connection with the negotiation and syndication of this Agreement or pursuant to the terms of this Agreement (other than projections, if any, and pro forma information) contained any untrue statement of a material fact or omitted to state a material fact necessary to make the statements made therein not materially misleading. The projections, if any, and pro forma financial information contained in the materials referenced above are based upon good faith estimates and assumptions believed by management of the Borrower to be reasonable at the time made, it being recognized by the Lenders that such financial information as it relates to future events is not to be viewed as fact and that actual results during the period or periods covered by such financial information may differ from the projected results set forth therein by a material amount.

(k)           The Borrower is, individually and together with its Subsidiaries, Solvent.

ARTICLE V

COVENANTS OF THE BORROWER

SECTION 5.01.  Affirmative Covenants.  So long as any Advance shall remain unpaid or any Lender shall have any Commitment hereunder, the Borrower will:

(a)           Compliance with Laws, Etc. Comply, and cause each of its Subsidiaries to comply with all applicable laws, rules, regulations and orders, such compliance to include, without limitation, compliance with ERISA, Environmental Laws and the Patriot Act except to the extent that failure to comply therewith would not reasonably be expected, individually or in the aggregate, to result in a Material Adverse Effect.

(b)           Payment of Taxes, Etc. Pay and discharge, and cause each of its Subsidiaries to pay and discharge, before the same shall become delinquent, (i) all taxes, assessments and governmental charges or levies imposed upon it or upon its property and (ii) all lawful claims that, if unpaid, might by law become a Lien upon its property; provided, however, that neither the Borrower nor any of its Subsidiaries shall be required to pay or discharge any such tax, assessment, charge or claim if (i) it is being contested in good faith and by proper proceedings and as to which appropriate reserves are being maintained or (ii) the nonpayment of all such taxes, assessments, charges or claims in the aggregate would not reasonably be expected, individually or in the aggregate, to result in a Material Adverse Effect.

(c)           Maintenance of Insurance. Maintain, and cause each of its Subsidiaries to maintain, insurance with responsible and reputable insurance companies or associations in such amounts and covering such risks as is usually carried by companies of comparable size and financial strength engaged in similar businesses and owning similar properties in the same general areas in which the Borrower or such Subsidiary operates, which may include self-insurance, if determined by the Borrower to be reasonably prudent and consistent with business practices as in effect on the date hereof.

(d)           Preservation of Existence, Etc. Preserve and maintain, and cause each of its Subsidiaries to preserve and maintain, its (i) legal existence; provided, however, that the Borrower and its Subsidiaries may consummate any merger or consolidation permitted under Section 5.02(b) and (ii) rights (charter and statutory) and franchises; provided further that neither the Borrower nor any of its Subsidiaries shall be required to preserve any right or franchise if the Board of Directors (or persons performing similar functions) of or on behalf of the Borrower or such Subsidiary shall determine that the preservation thereof is no longer desirable in the conduct of the business of the Borrower or such Subsidiary, as the case may be, and that the loss thereof is not reasonably likely to have a Material Adverse Effect.

(e)           Visitation Rights. At any reasonable time and from time to time and upon reasonable notice, permit the Agent or any of its agents or representatives, to (i) permit the Agent or any representatives thereof to examine and make copies of and abstracts from the records and books of account of, and visit the properties of, the Borrower and any of its Subsidiaries, and to discuss the affairs, finances and accounts of the Borrower and any of its Subsidiaries with any of their officers or directors and (ii) use commercially reasonable efforts to provide for the Agent or any representatives thereof (in the presence of representatives of the Borrower) to meet with the independent certified public accountants of the Borrower and its Subsidiaries; provided, that any such visits or inspections shall be subject to such conditions as the Borrower and each of its Subsidiaries shall deem necessary based on reasonable considerations of safety and security; and provided, further, that neither the Borrower nor any Subsidiary shall be required to disclose to the Agent or any representatives thereof any information which is subject to the attorney-client privilege or attorney work-product privilege properly asserted by the applicable Person to prevent the loss of such privilege in connection with such information or which is prevented from disclosure pursuant to a confidentiality agreement with third parties.

(f)            Keeping of Books. Keep, and cause each of its Subsidiaries to keep, proper books of record and account, in which full and correct entries shall be made of all financial transactions and the assets and business of the Borrower and each such Subsidiary in accordance with generally accepted accounting principles in effect from time to time.

(g)           Maintenance of Properties, Etc. Maintain and preserve, and cause each of its Subsidiaries to maintain and preserve, all of its properties that are used or useful in the conduct of its business in good

working order and condition, ordinary wear and tear excepted, except to the extent that failure to do so would not, in the aggregate, reasonably be expected to have a Material Adverse Effect.

(h)           Transactions with Affiliates. Conduct, and cause each of its Subsidiaries to conduct, all transactions otherwise permitted under this Agreement with any of their Affiliates on terms that are fair and reasonable and no less favorable to the Borrower or such Subsidiary than it would obtain in a comparable arm’s-length transaction with a Person not an Affiliate.

(i)            Reporting Requirements. Furnish to the Lenders:

(i)            as soon as available and in any event within 45 days after the end of each of the first three quarters of each fiscal year of the Borrower, the unaudited Consolidated balance sheet of the Borrower and its Subsidiaries as of the end of such quarter and unaudited Consolidated statements of income and cash flows of the Borrower and its Subsidiaries for the period commencing at the end of the previous fiscal year and ending with the end of such quarter, duly certified (subject to year-end audit adjustments) by the chief financial officer (or person performing similar functions) of the General Partner as having been prepared in accordance with generally accepted accounting principles and certificates of the chief executive officer, chief financial officer or controller of the Borrower (or the General Partner) as to compliance with the terms of this Agreement and setting forth in reasonable detail the calculations necessary to demonstrate compliance with Section 5.03, provided that in the event of any change in generally accepted accounting principles used in the preparation of such financial statements, the Borrower shall also provide, if necessary for the determination of compliance with Section 5.03, a statement of reconciliation conforming such financial statements to GAAP;

(ii)           as soon as available and in any event within 105 days after the end of each fiscal year of the Borrower, a copy of the annual audit report for such year for the Borrower and its Subsidiaries, containing the Consolidated balance sheet of the Borrower and its Subsidiaries as of the end of such fiscal year and Consolidated statements of income and cash flows of the Borrower and its Subsidiaries for such fiscal year, in each case accompanied by an opinion, without a “going concern” or like qualification or exception, or qualification arising out of the scope of the audit, by KPMG LLP or other independent public accountants of nationally recognized standing and certificates of the chief financial officer (or person performing similar functions) of the Borrower (or the General Partner) as to compliance with the terms of this Agreement and setting forth in reasonable detail the calculations necessary to demonstrate compliance with Section 5.03, provided that in the event of any change in generally accepted accounting principles used in the preparation of such financial statements, the Borrower shall also provide, if necessary for the determination of compliance with Section 5.03, a statement of reconciliation conforming such financial statements to GAAP;

(iii)          as soon as possible and in any event within five Business Days after the occurrence of each Default continuing on the date of such statement, a statement of the chief financial officer (or person performing similar functions) of the Borrower (or the General Partner) setting forth details of such Default and the action that the Borrower has taken and proposes to take with respect thereto;

(iv)          promptly after the sending or filing thereof, copies of all reports that the Borrower sends to any of its securityholders, and copies of all reports and registration statements that the Borrower or any Subsidiary files with the SEC;

(v)           promptly after the commencement thereof, notice of all actions and proceedings before any court, governmental agency or arbitrator affecting the General Partner, the Borrower or any of its Subsidiaries of the type described in Section 4.01(g); and

(vi)          such other information respecting the Borrower or any of its Subsidiaries as any Lender through the Agent may from time to time reasonably request.

Notwithstanding the foregoing, the Borrower shall be deemed to have delivered the reports and registration statements required to be delivered pursuant to the foregoing clause (iv) upon the filing of such financial statements, reports and registration statements by the Borrower through the SEC’s EDGAR system.

SECTION 5.02.  Negative Covenants.  So long as any Advance shall remain unpaid or any Lender shall have any Commitment hereunder, the Borrower will not:

(a)           Liens, Etc. Create or suffer to exist, or permit any of its Subsidiaries to create or suffer to exist, any Lien on or with respect to any of its properties, whether now owned or hereafter acquired, or assign, or permit any of its Subsidiaries to assign, any right to receive income, other than:

(i)            Permitted Liens,

(ii)           purchase money Liens upon or in any real property or equipment acquired or held by the Borrower or any Subsidiary in the ordinary course of business to secure the purchase price of such property or equipment or to secure Debt incurred solely for the purpose of financing the acquisition of such property or equipment, or Liens existing on such property or equipment at the time of its acquisition (other than any such Liens created in contemplation of such acquisition that were not incurred to finance the acquisition of such property) or extensions, renewals or replacements of any of the foregoing for the same or a lesser amount, provided, however, that no such Lien shall extend to or cover any properties of any character other than the real property or equipment being acquired, and no such extension, renewal or replacement shall extend to or cover any properties not theretofore subject to the Lien being extended, renewed or replaced, provided further that the aggregate principal amount of the indebtedness secured by the Liens referred to in this clause (ii) shall not exceed $10,000,000 at any time outstanding,

(iii)          the Liens existing on the Effective Date and described on Schedule 5.02(a) hereto,

(iv)          Liens on property of a Person existing at the time such Person is merged into or consolidated with the Borrower or any Subsidiary of the Borrower or becomes a Subsidiary of the Borrower; provided that such Liens were not created in contemplation of such merger, consolidation or acquisition and do not extend to any assets other than those of the Person so merged into or consolidated with the Borrower or such Subsidiary or acquired by the Borrower or such Subsidiary,

(v)           attachment or judgment Liens not constituting an Event of Default,

(vi)          banker’s liens, rights of setoff and similar Liens with respect to cash and cash equivalents on deposit in one or more bank accounts in the ordinary course of business,

(vii)         Liens in favor of collecting banks pursuant to Section 4-208 and Liens in favor of a buyer of goods arising pursuant to Section 2-711 of the applicable Uniform Commercial Code,

(viii)        Liens solely on any cash earnest money deposits made by the Borrower or any of its Subsidiaries in connection with any letter of intent or purchase agreement,

(ix)           other Liens securing Debt or Hedge Agreements in an aggregate principal amount not to exceed $5,000,000 at any time outstanding, and

(i)            the  replacement, extension or renewal of any Lien permitted by clause (iii) or (iv) above upon or in the same property theretofore subject thereto or the replacement, extension or renewal (without increase in the amount or change in any direct or contingent obligor) of the Debt secured thereby.

(b)           Mergers, Etc. Merge or consolidate with or into, or convey, transfer, lease or otherwise dispose of (whether in one transaction or in a series of transactions) all or substantially all of its assets (whether now owned or hereafter acquired) to, any Person, or permit any of its Subsidiaries to do so, except that any Subsidiary of the Borrower may merge or consolidate with or into, or dispose of assets to, any other Subsidiary of the Borrower, and except that any Subsidiary of the Borrower may merge into or dispose of assets to the Borrower and the Borrower may merge with any other Person so long as the Borrower is the surviving corporation, provided, in each case, that no Default shall have occurred and be continuing at the time of such proposed transaction or would result therefrom.

(c)           Change in Nature of Business. Engage, or permit any of its Subsidiaries to engage, in any business other than those businesses in which the Borrower and its Subsidiaries are engaged on the Effective Date or a business reasonably related thereto or such other lines of business as may be consented to by the Required Lenders.

SECTION 5.03.  Financial Covenants.  So long as any Advance shall remain unpaid or any Lender shall have any Commitment hereunder, the Borrower will:

(a)           Coverage Ratio. Maintain as of the last day of any fiscal quarter a ratio of Adjusted Cash Flow to Interest Expense, in each case, by the Borrower and its Subsidiaries for the period of four fiscal quarters then ended, of not less than 3.50 to 1.00.

(b)           Leverage Ratio. Maintain at all times a Leverage Ratio of not greater than 4.50 to 1.00.

ARTICLE VI

EVENTS OF DEFAULT

SECTION 6.01.  Events of Default.  If any of the following events (“Events of Default”) shall occur and be continuing:

(a)           The Borrower shall fail to pay any principal of any Advance when the same becomes due and payable; or the Borrower shall fail to pay any interest on any Advance or make any other payment of fees or other amounts payable under this Agreement or any Note within five Business Days after the same becomes due and payable; or

(b)           Any representation or warranty made by the Borrower herein or by the Borrower (or any of its officers (or persons performing similar functions)) in connection with this Agreement shall prove to have been incorrect in any material respect when made; or

(c)           (i) The Borrower shall fail to perform or observe any term, covenant or agreement contained in Section 5.01(d)(i), (e) or (i), 5.02 or 5.03, or (ii) the Borrower shall fail to perform or observe any other term, covenant or agreement contained in this Agreement on its part to be performed or observed if such failure shall remain unremedied for 30 days after written notice thereof shall have been given to the Borrower by the Agent or any Lender; or

(d)           (i) The Borrower or any of its Significant Subsidiaries shall fail to pay any principal of or premium or interest on any Debt that is outstanding in a principal or notional amount of at least $15,000,000 in the aggregate (but excluding Debt outstanding hereunder) of the Borrower or such Significant Subsidiary (as the case may be), when the same becomes due and payable (whether by

scheduled maturity, required prepayment, acceleration, demand or otherwise), and such failure shall continue after the applicable grace period, if any, specified in the agreement or instrument relating to such Debt; or any other event shall occur or condition shall exist under any agreement or instrument relating to any such Debt and shall continue after the applicable grace period, if any, specified in such agreement or instrument, if the effect of such event or condition is to accelerate, or to permit the acceleration of, the maturity of such Debt; or any such Debt shall be declared to be due and payable, or required to be prepaid or redeemed (other than by a regularly scheduled required prepayment or redemption), purchased or defeased, or an offer to prepay, redeem, purchase or defease such Debt shall be required to be made, in each case prior to the stated maturity thereof; or (ii) (A) there occurs under any Hedge Agreement an Early Termination Date (as defined in such Hedge Agreement) resulting from any event of default under such Hedge Agreement as to which the Borrower or any of its Significant Subsidiaries is the Defaulting Party (as defined in such Hedge Agreement) and the Hedge Termination Value owed by the Borrower or any of its Significant Subsidiaries as a result thereof is greater than (individually or collectively) $15,000,000, or (B) there occurs under any Hedge Agreement an Early Termination Date (as defined in such Hedge Agreement) resulting from any Termination Event (as so defined) under such Hedge Agreement as to which the Borrower or any of its Significant Subsidiaries is an Affected Party (as so defined) and the Swap Termination Value owed by the Borrower or any of its Significant Subsidiaries as a result thereof is greater than (individually or collectively) $15,000,000 and such amount is not paid when due under such Hedge Agreement; or

(e)           The General Partner, the Borrower or any of its Significant Subsidiaries shall generally not pay its debts as such debts become due, or shall admit in writing its inability to pay its debts generally, or shall make a general assignment for the benefit of creditors; or any proceeding shall be instituted by or against the General Partner, the Borrower or any of its Significant Subsidiaries seeking to adjudicate it a bankrupt or insolvent, or seeking liquidation, winding up, reorganization, arrangement, adjustment, protection, relief, or composition of it or its debts under any law relating to bankruptcy, insolvency or reorganization or relief of debtors, or seeking the entry of an order for relief or the appointment of a receiver, trustee, custodian or other similar official for it or for any substantial part of its property and, in the case of any such proceeding instituted against it (but not instituted by it), either such proceeding shall remain undismissed or unstayed for a period of 60 days, or the entry of an order for relief against, or the appointment of a receiver, trustee, custodian or other similar official for, it or for any substantial part of its property shall occur; or the General Partner, the Borrower or any of its Significant Subsidiaries shall take any corporate action to authorize any of the actions set forth above in this subsection (e); or

(f)            Judgments or orders for the payment of money in excess of $15,000,000 in the aggregate shall be rendered against the Borrower or any of its Significant Subsidiaries and either (i) enforcement proceedings shall have been commenced by any creditor upon such judgment or order or (ii) there shall be any period of 30 consecutive days during which a stay of enforcement of such judgment or order, by reason of a pending appeal or otherwise, shall not be in effect; provided, however, that any such judgment or order shall not be an Event of Default under this Section 6.01(f) if and for so long as (i) the amount of such judgment or order is covered (subject to customary deductibles) by a valid and binding policy of insurance between the defendant and the insurer covering payment thereof and (ii) such insurer, which shall be rated at least “A-” by A.M. Best Company, has been notified of, and has not denied coverage of, the amount of such judgment or order; or

(g)           Any non-monetary judgment or order shall be rendered against the Borrower or any of its Significant Subsidiaries that is reasonably expected to have a Material Adverse Effect, and there shall be any period of 30 consecutive days during which a stay of enforcement of such judgment or order, by reason of a pending appeal or otherwise, shall not be in effect; or

(h)           (i) Any Person or two or more Persons acting in concert (other than TransCanada Corporation or any of its Subsidiaries) shall have acquired beneficial ownership (within the meaning of Rule 13d-3 of the SEC under the Securities Exchange Act of 1934), directly or indirectly, of Voting Stock of the General Partner (or other securities convertible into such Voting Stock) (A) representing 50% or

more of the combined voting power of all Voting Stock of the General Partner or (B) representing the combined voting power of all Voting Stock of the General Partner more than that owned, directly or indirectly, by TransCanada Corporation; or (ii) any Person or two or more Persons acting in concert (other than TransCanada Corporation or any of its Subsidiaries or any other Person reasonably acceptable to the Required Lenders) shall have acquired by contract or otherwise, or shall have entered into a contract or arrangement that, upon consummation, will result in its or their acquisition of the power to exercise, directly or indirectly, a controlling influence over the management or policies of the General Partner; or (iii) the General Partner shall for any reason cease to be the managing general partner of the Borrower; or

(i)            The Borrower or any of its ERISA Affiliates shall incur, or shall be reasonably likely to incur liability in excess of $15,000,000 in the aggregate as a result of one or more of the following:  (i) the occurrence of any ERISA Event; (ii) the partial or complete withdrawal of the Borrower or any of its ERISA Affiliates from a Multiemployer Plan; or (iii) the reorganization or termination of a Multiemployer Plan;

then, and in any such event, the Agent (i) shall at the request, or may with the consent, of the Required Lenders, by notice to the Borrower, declare the obligation of each Lender to make Advances to be terminated, whereupon the same shall forthwith terminate, and (ii) shall at the request, or may with the consent, of the Required Lenders, by notice to the Borrower, declare the Advances, all interest thereon and all other amounts payable under this Agreement to be forthwith due and payable, whereupon the Advances, all such interest and all such amounts shall become and be forthwith due and payable, without presentment, demand, protest or further notice of any kind, all of which are hereby expressly waived by the Borrower; provided, however, that in the event of an actual or deemed entry of an order for relief with respect to the Borrower under the Federal Bankruptcy Code, (A) the obligation of each Lender to make Advances shall automatically be terminated and (B) the Advances, all such interest and all such amounts shall automatically become and be due and payable, without presentment, demand, protest or any notice of any kind, all of which are hereby expressly waived by the Borrower.

ARTICLE VII

THE AGENT

SECTION 7.01.  Authorization and Action.  Each Lender hereby appoints and authorizes the Agent to take such action as agent on its behalf and to exercise such powers and discretion under this Agreement as are delegated to the Agent by the terms hereof, together with such powers and discretion as are reasonably incidental thereto. As to any matters not expressly provided for by this Agreement (including, without limitation, enforcement or collection of the Notes), the Agent shall not be required to exercise any discretion or take any action, but shall be required to act or to refrain from acting (and shall be fully protected in so acting or refraining from acting) upon the instructions of the Required Lenders, and such instructions shall be binding upon all Lenders and all holders of Notes; provided, however, that the Agent shall not be required to take any action that exposes the Agent to personal liability or that is contrary to this Agreement or applicable law. The Agent agrees to give to each Lender prompt notice of each notice given to it by the Borrower pursuant to the terms of this Agreement.

SECTION 7.02.  Agent’s Reliance, Etc.  Neither the Agent nor any of its directors, officers, agents or employees shall be liable for any action taken or omitted to be taken by it or them under or in connection with this Agreement, except for its or their own gross negligence or willful misconduct. Without limitation of the generality of the foregoing, the Agent:  (i) may treat the Lender that made any Advance as the holder of the Debt resulting therefrom until the Agent receives and accepts an Assignment and Acceptance entered into by such Lender, as assignor, and an Eligible Assignee, as assignee, as provided in Section 8.07; (ii) may consult with legal counsel (including counsel for the Borrower), independent public accountants and other experts selected by it and shall not be liable for any action taken or omitted to be taken in good faith by it in accordance with  the advice of such counsel, accountants or experts; (iii) makes no warranty or representation to any Lender and shall not be responsible to any Lender for any statements, warranties or representations (whether written or oral) made in or in connection with this Agreement; (iv) shall not have any duty to ascertain or to inquire as to the performance, observance or satisfaction of any of the terms, covenants or conditions of this Agreement on the part of the Borrower or  the existence at any time of any Default or to inspect the property (including the books and records) of the Borrower;

(v) shall not be responsible to any Lender for the due execution, legality, validity, enforceability, genuineness, sufficiency or value of this Agreement or any other instrument or document furnished pursuant hereto; and (vi) shall incur no liability under or in respect of this Agreement by acting upon any notice, consent, certificate or other instrument or writing (which may be by telecopier) believed by it to be genuine and signed or sent by the proper party or parties.

SECTION 7.03.  CNAI and Affiliates.  With respect to its Commitment, the Advances made by it and the Note issued to it, CNAI shall have the same rights and powers under this Agreement as any other Lender and may exercise the same as though it were not the Agent; and the term “Lender” or “Lenders” shall, unless otherwise expressly indicated, include CNAI in its individual capacity. CNAI and its Affiliates may accept deposits from, lend money to, act as trustee under indentures of, accept investment banking engagements from and generally engage in any kind of business with, the Borrower, any of its Subsidiaries and any Person who may do business with or own securities of the Borrower or any such Subsidiary, all as if CNAI were not the Agent and without any duty to account therefor to the Lenders. The Agent shall have no duty to disclose any information obtained or received by it or any of its Affiliates relating to the Borrower or any of its Subsidiaries to the extent such information was obtained or received in any capacity other than as Agent.

SECTION 7.04.  Lender Credit Decision.  Each Lender acknowledges that it has, independently and without reliance upon the Agent or any other Lender and based on the financial statements referred to in Section 4.01 and such other documents and information as it has deemed appropriate, made its own credit analysis and decision to enter into this Agreement. Each Lender also acknowledges that it will, independently and without reliance upon the Agent or any other Lender and based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under this Agreement.

SECTION 7.05.  Indemnification.  The Lenders agree to indemnify the Agent (to the extent not reimbursed by the Borrower), from and against such Lender’s pro rata share (determined as provided below) of any and all liabilities, obligations, losses, damages, penalties, actions, judgments, suits, costs, expenses or disbursements of any kind or nature whatsoever that may be imposed on, incurred by, or asserted against the Agent in any way relating to or arising out of this Agreement or any action taken or omitted by the Agent under this Agreement (collectively, the “Indemnified Costs”), provided that no Lender shall be liable for any portion of the Indemnified Costs resulting from the Agent’s gross negligence or willful misconduct. Without limitation of the foregoing, each Lender agrees to reimburse the Agent promptly upon demand for its ratable share of any out-of-pocket expenses (including counsel fees) incurred by the Agent in connection with the preparation, execution, delivery, administration, modification, amendment or enforcement (whether through negotiations, legal proceedings or otherwise) of, or legal advice in respect of rights or responsibilities under, this Agreement, to the extent that the Agent is not reimbursed for such expenses by the Borrower. In the case of any investigation, litigation or proceeding giving rise to any Indemnified Costs, this Section 7.05 applies whether any such investigation, litigation or proceeding is brought by the Agent, any Lender or a third party. For purposes of this Section 7.05(a), the Lenders’ respective pro rata shares of any amount shall be determined, at any time, according to the aggregate principal amount of the Advances outstanding at such time and owing to the respective Lenders.

SECTION 7.06.  Successor Agent.  The Agent may resign at any time by giving written notice thereof to the Lenders and the Borrower and may be removed at any time with or without cause by the Required Lenders. Upon any such resignation or removal, the Required Lenders shall have the right to appoint a successor Agent, which successor Agent (unless an Event of Default shall have occurred and be continuing) shall be subject to the approval of the Borrower (which approval will not be unreasonably withheld or delayed). If no successor Agent shall have been so appointed by the Required Lenders, and if no successor Agent shall have accepted such appointment, within 30 days after the retiring Agent’s giving of notice of resignation or the Required Lenders’ removal of the retiring Agent, then the retiring Agent may, on behalf of the Lenders, appoint a successor Agent, which shall be a commercial bank organized under the laws of the United States of America or of any State thereof and having a combined capital and surplus of at least $500,000,000, which successor Agent (unless an Event of Default shall have occurred and be continuing) shall be subject to the approval of the Borrower (which approval will not be unreasonably withheld or delayed). Upon the acceptance of any appointment as Agent hereunder by a successor Agent, such successor Agent shall thereupon succeed to and become vested with all the rights, powers, discretion, privileges and duties of the retiring Agent, and the retiring Agent shall be discharged from its duties and

obligations under this Agreement. After any retiring Agent’s resignation or removal hereunder as Agent, the provisions of this Article VII shall inure to its benefit as to any actions taken or omitted to be taken by it while it was Agent under this Agreement.

SECTION 7.07.  Other Agents.  Each Lender hereby acknowledges that neither the documentation agent nor any other Lender designated as any “Agent” on the signature pages hereof has any liability hereunder other than in its capacity as a Lender.

ARTICLE VIII

MISCELLANEOUS

SECTION 8.01.  Amendments, Etc.  No amendment or waiver of any provision of this Agreement or the Notes, nor consent to any departure by the Borrower therefrom, shall in any event be effective unless the same shall be in writing and signed by the Required Lenders, and then such waiver or consent shall be effective only in the specific instance and for the specific purpose for which given; provided, however, that (a) no amendment, waiver or consent shall, unless in writing and signed by all the Lenders, do any of the following:  (i) waive any of the conditions specified in Section 3.01, (ii) change the percentage of the Commitments or of the aggregate unpaid principal amount of the Advances, or the number of Lenders, that shall be required for the Lenders or any of them to take any action hereunder or (iii) amend this Section 8.01 and (b) no amendment, waiver or consent shall, unless in writing and signed by the Required Lenders and each Lender that is directly affected by such amendment, waiver or consent, (i) reduce the principal of, or interest on, the Advances or any fees or other amounts payable hereunder to such Lender or (ii) postpone any date fixed for any payment of principal of, or interest on, the Advances or any fees or other amounts payable hereunder to such Lender; and provided further that no amendment, waiver or consent shall, unless in writing and signed by the Agent in addition to the Lenders required above to take such action, affect the rights or duties of the Agent under this Agreement or any Note.

SECTION 8.02.  Notices, Etc.  (a)  All notices and other communications provided for hereunder shall be either (x) in writing (including telecopier or telegraphic communication) and mailed, telecopied, telegraphed or delivered or (y) as and to the extent set forth in Section 8.02(b) and in the proviso to this Section 8.02(a), if to the Borrower, at its address at 450 - 1 Street SW, Calgary, AB  T2P 5H1, Attention: Secretary, Fax No. 403 ###-###-####; if  to any Initial Lender, at its Domestic Lending Office specified opposite its name on Schedule I hereto; if to any other Lender, at its Domestic Lending Office specified in the Assignment and Acceptance pursuant to which it became a Lender; and if to the Agent, at its address at Two Penns Way, New Castle, Delaware 19720, Attention: Bank Loan Syndications Department; or, as to the Borrower or the Agent, at such other address as shall be designated by such party in a written notice to the other parties and, as to each other party, at such other address as shall be designated by such party in a written notice to the Borrower and the Agent, provided that materials required to be delivered pursuant to Section 5.01(i)(i), (ii) or (iv) shall be delivered to the Agent as specified in Section 8.02(b) or as otherwise specified to the Borrower by the Agent. All such notices and communications shall, when mailed, telecopied or e-mailed, be effective when deposited in the mails, telecopied or confirmed by e-mail, respectively, except that notices and communications to the Agent pursuant to Article II, III or VII shall not be effective until received by the Agent. Delivery by telecopier of an executed counterpart of any amendment or waiver of any provision of this Agreement or the Notes or of any Exhibit hereto to be executed and delivered hereunder shall be effective as delivery of a manually executed counterpart thereof.

(b)           So long as CNAI or any of its Affiliates is the Agent, materials required to be delivered pursuant to Section 5.01(i)(i), (ii) and (iv) shall be delivered to the Agent in an electronic medium in a format acceptable to the Agent and the Lenders by e-mail at ***@***. The Borrower agrees that the Agent may make such materials, as well as any other written information, documents, instruments and other material relating to the Borrower, any of its Subsidiaries or any other materials or matters relating to this Agreement, the Notes or any of the transactions contemplated hereby (collectively, the “Communications”) available to the Lenders by posting such notices on Intralinks or a substantially similar electronic system (the “Platform”). The Borrower acknowledges that (i) the distribution of material through an electronic medium is not necessarily secure and that there are confidentiality and other risks associated with such distribution, (ii) the Platform is provided “as is” and “as available” and (iii) neither the Agent nor any of its Affiliates warrants the accuracy, adequacy or completeness of the Communications or the Platform and each expressly disclaims liability for errors or omissions in the

Communications or the Platform. No warranty of any kind, express, implied or statutory, including, without limitation, any warranty of merchantability, fitness for a particular purpose, non-infringement of third party rights or freedom from viruses or other code defects, is made by the Agent or any of its Affiliates in connection with the Platform.

(c)           Each Lender agrees that notice to it (as provided in the next sentence) (a “Notice”) specifying that any Communications have been posted to the Platform shall constitute effective delivery of such information, documents or other materials to such Lender for purposes of this Agreement; provided that if requested by any Lender the Agent shall deliver a copy of the Communications to such Lender by email or telecopier. Each Lender agrees (i) to notify the Agent in writing of such Lender’s e-mail address to which a Notice may be sent by electronic transmission (including by electronic communication) on or before the date such Lender becomes a party to this Agreement (and from time to time thereafter to ensure that the Agent has on record an effective e-mail address for such Lender) and (ii) that any Notice may be sent to such e-mail address.

SECTION 8.03.  No Waiver; Remedies.  No failure on the part of any Lender or the Agent to exercise, and no delay in exercising, any right hereunder or under any Note shall operate as a waiver thereof; nor shall any single or partial exercise of any such right preclude any other or further exercise thereof or the exercise of any other right. The remedies herein provided are cumulative and not exclusive of any remedies provided by law.

SECTION 8.04.  Costs and Expenses.  (a)  The Borrower agrees to pay on demand all reasonable costs and expenses of the Agent in connection with the preparation, execution, delivery, administration, modification and amendment of this Agreement, the Notes and the other documents to be delivered hereunder, including, without limitation, (A) all due diligence, syndication (including printing, distribution and bank meetings), transportation, computer, duplication, appraisal, consultant, and audit expenses and (B) the reasonable fees and expenses of counsel for the Agent with respect thereto and with respect to advising the Agent as to its rights and responsibilities under this Agreement. The Borrower further agrees to pay on demand all reasonable costs and expenses of the Agent and the Lenders, if any (including, without limitation, reasonable counsel fees and expenses), in connection with the enforcement (whether through negotiations, legal proceedings or otherwise) of this Agreement, the Notes and the other documents to be delivered hereunder, including, without limitation, reasonable fees and expenses of counsel for the Agent and each Lender in connection with the enforcement of rights under this Section 8.04(a).

(b)           The Borrower agrees to indemnify and hold harmless the Agent and each Lender and each of their Affiliates and their officers, directors, employees, agents and advisors (each, an “Indemnified Party”) from and against any and all claims, damages, losses, liabilities and expenses (including, without limitation, reasonable fees and expenses of counsel) incurred by or asserted or awarded against any Indemnified Party, in each case arising out of or in connection with or by reason of (including, without limitation, in connection with any investigation, litigation or proceeding or preparation of a defense in connection therewith) (i) the Notes, this Agreement, any of the transactions contemplated herein or the actual or proposed use of the proceeds of the Advances or (ii) the actual or alleged presence of Hazardous Materials on any property of the Borrower or any of its Subsidiaries or any Environmental Action relating in any way to the Borrower or any of its Subsidiaries, except to the extent such claim, damage, loss, liability or expense is found in a final, non-appealable judgment by a court of competent jurisdiction to have resulted from such Indemnified Party’s gross negligence or willful misconduct. In the case of an investigation, litigation or other proceeding to which the indemnity in this Section 8.04(b) applies, such indemnity shall be effective whether or not such investigation, litigation or proceeding is brought by the Borrower, its directors, equityholders or creditors or an Indemnified Party or any other Person, whether or not any Indemnified Party is otherwise a party thereto and whether or not the transactions contemplated hereby are consummated. The Borrower also agrees not to assert any claim for special, indirect, consequential or punitive damages against the Agent, any Lender, any of their Affiliates, or any of their respective directors, officers, employees, attorneys and agents, on any theory of liability, arising out of or otherwise relating to the Notes, this Agreement, any of the transactions contemplated herein or the actual or proposed use of the proceeds of the Advances.

(c)           If any payment of principal of, or Conversion of, any Eurodollar Rate Advance is made by the Borrower to or for the account of a Lender other than on the last day of the Interest Period for such Advance, as a result of a payment or Conversion pursuant to Section 2.07(d) or (e), 2.09 or 2.11, acceleration of the maturity of the Notes pursuant to Section 6.01 or for any other reason, or by an Eligible Assignee to a Lender other than on

the last day of the Interest Period for such Advance upon an assignment of rights and obligations under this Agreement pursuant to Section 8.07 as a result of a demand by the Borrower pursuant to Section 8.07(a), the Borrower shall, upon demand by such Lender (with a copy of such demand to the Agent), pay to the Agent for the account of such Lender any amounts required to compensate such Lender for any additional losses, costs or expenses that it may reasonably incur as a result of such payment or Conversion, including, without limitation, any loss (including loss of anticipated profits), cost or expense incurred by reason of the liquidation or reemployment of deposits or other funds acquired by any Lender to fund or maintain such Advance.

(d)           Without prejudice to the survival of any other agreement of the Borrower hereunder, the agreements and obligations of the Borrower contained in Sections 2.10, 2.13 and 8.04 shall survive the payment in full of principal, interest and all other amounts payable hereunder and under the Notes.

SECTION 8.05.  Right of Set-off.  Upon (i) the occurrence and during the continuance of any Event of Default and (ii) the making of the request or the granting of the consent specified by Section 6.01 to authorize the Agent to declare the Notes due and payable pursuant to the provisions of Section 6.01, each Lender and each of its Affiliates is hereby authorized at any time and from time to time, to the fullest extent permitted by law, to set off and apply any and all deposits (general or special, time or demand, provisional or final) at any time held and other indebtedness at any time owing by such Lender or such Affiliate to or for the credit or the account of the Borrower against any and all of the obligations of the Borrower now or hereafter existing under this Agreement and the Note held by such Lender, whether or not such Lender shall have made any demand under this Agreement or such Note and although such obligations may be unmatured. Each Lender agrees promptly to notify the Borrower after any such set-off and application, provided that the failure to give such notice shall not affect the validity of such set-off and application. The rights of each Lender and its Affiliates under this Section are in addition to other rights and remedies (including, without limitation, other rights of set-off) that such Lender and its Affiliates may have.

SECTION 8.06.  Binding Effect.  This Agreement shall become effective (other than Section 2.01, which shall only become effective upon satisfaction of the conditions precedent set forth in Section 3.01) when it shall have been executed by the Borrower and the Agent and when the Agent shall have been notified by each Initial Lender that such Initial Lender has executed it and thereafter shall be binding upon and inure to the benefit of the Borrower, the Agent and each Lender and their respective successors and assigns, except that the Borrower shall not have the right to assign its rights hereunder or any interest herein without the prior written consent of the Lenders.

SECTION 8.07.  Assignments and Participations.  (a)  Each Lender may and, if demanded by the Borrower (following a demand by such Lender pursuant to Section 2.10 or 2.13) upon at least five Business Days’ notice to such Lender and the Agent, will assign to one or more Persons all or a portion of its rights and obligations under this Agreement (including, without limitation, all or a portion of its Commitment, the Advances owing to it and the Note or Notes held by it); provided, however, that (i) each such assignment shall be of a constant, and not a varying, percentage of all rights and obligations under this Agreement, (ii) except in the case of an assignment to a Person that, immediately prior to such assignment, was a Lender or an assignment of all of a Lender’s rights and obligations under this Agreement, the amount of the Commitment of the assigning Lender being assigned pursuant to each such assignment (determined as of the date of the Assignment and Acceptance with respect to such assignment) shall in no event be less than $5,000,000 unless the Borrower and the Agent otherwise agree, (iii) each such assignment shall be to an Eligible Assignee, (iv) each such assignment made as a result of a demand by the Borrower pursuant to this Section 8.07(a) shall be arranged by the Borrower after consultation with the Agent and shall be either an assignment of all of the rights and obligations of the assigning Lender under this Agreement or an assignment of a portion of such rights and obligations made concurrently with another such assignment or other such assignments that together cover all of the rights and obligations of the assigning Lender under this Agreement, (v) no Lender shall be obligated to make any such assignment as a result of a demand by the Borrower pursuant to this Section 8.07(a) unless and until such Lender shall have received one or more payments from either the Borrower or one or more Eligible Assignees in an aggregate amount at least equal to the aggregate outstanding principal amount of the Advances owing to such Lender, together with accrued interest thereon to the date of payment of such principal amount and all other amounts payable to such Lender under this Agreement, and (vi) the parties to each such assignment shall execute and deliver to the Agent, for its acceptance and recording in the Register, an Assignment and Acceptance, together with any Note subject to such assignment and a processing and recordation fee of $3,500 payable by the parties to each such assignment, provided, however, that in the case of each

assignment made as a result of a demand by the Borrower, such recordation fee shall be payable by the Borrower except that no such recordation fee shall be payable in the case of an assignment made at the request of the Borrower to an Eligible Assignee that is an existing Lender. Upon such execution, delivery, acceptance and recording, from and after the effective date specified in each Assignment and Acceptance, (x) the assignee thereunder shall be a party hereto and, to the extent that rights and obligations hereunder have been assigned to it pursuant to such Assignment and Acceptance, have the rights and obligations of a Lender hereunder and (y) the Lender assignor thereunder shall, to the extent that rights and obligations hereunder have been assigned by it pursuant to such Assignment and Acceptance, relinquish its rights (other than its rights under Sections 2.10, 2.13 and 8.04 to the extent any claim thereunder relates to an event arising prior to such assignment) and be released from its obligations under this Agreement (and, in the case of an Assignment and Acceptance covering all or the remaining portion of an assigning Lender’s rights and obligations under this Agreement, such Lender shall cease to be a party hereto).

(b)           By executing and delivering an Assignment and Acceptance, the Lender assignor thereunder and the assignee thereunder confirm to and agree with each other and the other parties hereto as follows:  (i) other than as provided in such Assignment and Acceptance, such assigning Lender makes no representation or warranty and assumes no responsibility with respect to any statements, warranties or representations made in or in connection with this Agreement or the execution, legality, validity, enforceability, genuineness, sufficiency or value of this Agreement or any other instrument or document furnished pursuant hereto; (ii) such assigning Lender makes no representation or warranty and assumes no responsibility with respect to the financial condition of the General Partner or the Borrower or the performance or observance by the Borrower of any of its obligations under this Agreement or any other instrument or document furnished pursuant hereto; (iii) such assignee confirms that it has received a copy of this Agreement, together with copies of the financial statements referred to in Section 4.01 and such other documents and information as it has deemed appropriate to make its own credit analysis and decision to enter into such Assignment and Acceptance; (iv) such assignee will, independently and without reliance upon the Agent, such assigning Lender or any other Lender and based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under this Agreement; (v) such assignee confirms that it is an Eligible Assignee; (vi) such assignee appoints and authorizes the Agent to take such action as agent on its behalf and to exercise such powers and discretion under this Agreement as are delegated to the Agent by the terms hereof, together with such powers and discretion as are reasonably incidental thereto; and (vii) such assignee agrees that it will perform in accordance with their terms all of the obligations that by the terms of this Agreement are required to be performed by it as a Lender.

(c)           Upon its receipt of an Assignment and Acceptance executed by an assigning Lender and an assignee representing that it is an Eligible Assignee, together with any Note or Notes subject to such assignment, the Agent shall, if such Assignment and Acceptance has been completed and is in substantially the form of Exhibit C hereto, (i) accept such Assignment and Acceptance, (ii) record the information contained therein in the Register and (iii) give prompt notice thereof to the Borrower.

(d)           The Agent shall maintain at its address referred to in Section 8.02 a copy of each Assignment and Acceptance delivered to and accepted by it and a register for the recordation of the names and addresses of the Lenders and the Commitment of, and principal amount of the Advances owing to, each Lender from time to time (the “Register”). The entries in the Register shall be conclusive and binding for all purposes, absent manifest error, and the Borrower, the Agent and the Lenders may treat each Person whose name is recorded in the Register as a Lender hereunder for all purposes of this Agreement. The Register shall be available for inspection by the Borrower or any Lender at any reasonable time and from time to time upon reasonable prior notice.

(e)           Each Lender may sell participations to one or more banks or other entities (other than the Borrower or any of its Affiliates) in or to all or a portion of its rights and obligations under this Agreement (including, without limitation, all or a portion of its Commitment, the Advances owing to it and any Note or Notes held by it); provided, however, that (i) such Lender’s obligations under this Agreement (including, without limitation, its Commitment to the Borrower hereunder) shall remain unchanged, (ii) such Lender shall remain solely responsible to the other parties hereto for the performance of such obligations, (iii) such Lender shall remain the holder of any such Note for all purposes of this Agreement, (iv) the Borrower, the Agent and the other Lenders shall continue to deal solely and directly with such Lender in connection with such Lender’s rights and obligations under this Agreement and (v) no participant under any such participation shall have any right to approve any amendment or waiver of any provision of this Agreement or any Note, or any consent to any departure by the Borrower

therefrom, except to the extent that such amendment, waiver or consent would reduce the principal of, or interest on, the Notes or any fees or other amounts payable hereunder, in each case to the extent subject to such participation, or postpone any date fixed for any payment of principal of, or interest on, the Notes or any fees or other amounts payable hereunder, in each case to the extent subject to such participation. Notwithstanding anything to the contrary herein, a participant shall not be entitled to receive any greater payment under Section 2.10 or 2.13 than the applicable Lender would have been entitled to receive with respect to the participation sold to such participant. Any participant that is Lender organized under the laws of a jurisdiction outside the United States shall not be entitled to the benefits of Section 2.13 unless such participant complies with Section 2.13(e).

(f)            Any Lender may, in connection with any assignment or participation or proposed assignment or participation pursuant to this Section 8.07, disclose to the assignee or participant or proposed assignee or participant, any information relating to the Borrower furnished to such Lender by or on behalf of the Borrower; provided that, prior to any such disclosure, the assignee or participant or proposed assignee or participant shall agree to preserve the confidentiality of any Borrower Information relating to the Borrower received by it from such Lender to the standards set forth in Section 8.08.

(g)           Notwithstanding any other provision set forth in this Agreement, any Lender may at any time create a security interest in all or any portion of its rights under this Agreement (including, without limitation, the Advances owing to it and any Note or Notes held by it) in favor of any Federal Reserve Bank in accordance with Regulation A of the Board of Governors of the Federal Reserve System.

SECTION 8.08.  Confidentiality.  Neither the Agent nor any Lender may disclose to any Person any confidential, proprietary or non-public information of the Borrower furnished to the Agent or the Lenders by the Borrower (such information being referred to collectively herein as the “Borrower Information”), except that each of the Agent and each of the Lenders may disclose Borrower Information (i) to its and its affiliates’ employees, officers, directors, agents and advisors (it being understood that the Persons to whom such disclosure is made will be informed of the confidential nature of such Borrower Information and instructed to keep such Borrower Information confidential on substantially the same terms as provided herein), (ii) to the extent requested by any regulatory authority, (iii) to the extent required by applicable laws or regulations or by any subpoena or similar legal process, (iv) to any other party to this Agreement, (v) in connection with the exercise of any remedies hereunder or any suit, action or proceeding relating to this Agreement or the enforcement of rights hereunder, (vi) subject to an agreement containing provisions substantially the same as those of this Section 8.08, to any assignee, participant or swap counterparty or prospective assignee, participant or swap counterparty, (vii) to the extent such Borrower Information (A) is or becomes generally available to the public on a non-confidential basis other than as a result of a breach of this Section 8.08 by the Agent or such Lender, or (B) is or becomes available to the Agent or such Lender on a nonconfidential basis from a source other than the Borrower and (viii) with the consent of the Borrower; provided that, in the case of clauses (ii) or (iii), with the exception of disclosure to bank regulatory authorities, the Agent and each Lender agree, to the extent  practicable and legally permissible, to give the Borrower prompt prior notice so that it may seek a protective order or other appropriate remedy.

SECTION 8.09.  Governing Law.  This Agreement and the Notes shall be governed by, and construed in accordance with, the laws of the State of New York.

SECTION 8.10.  Execution in Counterparts.  This Agreement may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement. Delivery of an executed counterpart of a signature page to this Agreement by telecopier shall be effective as delivery of a manually executed counterpart of this Agreement.

SECTION 8.11.  Jurisdiction, Etc.  (a)  Each of the parties hereto hereby irrevocably and unconditionally submits, for itself and its property, to the nonexclusive jurisdiction of any New York State court or federal court of the United States of America sitting in New York City, and any appellate court from any thereof, in any action or proceeding arising out of or relating to this Agreement or the Notes, or for recognition or enforcement of any judgment, and each of the parties hereto hereby irrevocably and unconditionally agrees that all claims in respect of any such action or proceeding may be heard and determined in any such New York State court or, to the extent permitted by law, in such federal court. The Borrower hereby agrees that service of process in any such

action or proceeding brought in the any such New York State court or in such federal court may be made upon CT Corporation System at its offices at 1633 Broadway, New York, New York 10019 (the “Process Agent”) and the Borrower hereby irrevocably appoints the Process Agent its authorized agent to accept such service of process, and agrees that the failure of the Process Agent to give any notice of any such service shall not impair or affect the validity of such service or of any judgment rendered in any action or proceeding based thereon. The Borrower hereby further irrevocably consents to the service of process in any action or proceeding in such courts by the mailing thereof by any parties hereto by registered or certified mail, postage prepaid, to the Borrower at its address specified pursuant to Section 8.02. Each of the parties hereto agrees that a final judgment in any such action or proceeding shall be conclusive and may be enforced in other jurisdictions by suit on the judgment or in any other manner provided by law. Nothing in this Agreement shall affect any right that any party may otherwise have to bring any action or proceeding relating to this Agreement or the Notes in the courts of any jurisdiction.

(b)           Each of the parties hereto irrevocably and unconditionally waives, to the fullest extent it may legally and effectively do so, any objection that it may now or hereafter have to the laying of venue of any suit, action or proceeding arising out of or relating to this Agreement or the Notes in any New York State or federal court. Each of the parties hereto hereby irrevocably waives, to the fullest extent permitted by law, the defense of an inconvenient forum to the maintenance of such action or proceeding in any such court.

SECTION 8.12.  Patriot Act Notice.  Each Lender and the Agent (for itself and not on behalf of any Lender) hereby notifies the Borrower that pursuant to the requirements of the Patriot Act, it is required to obtain, verify and record information that identifies the Borrower, which information includes the name and address of the Borrower and other information that will allow such Lender or the Agent, as applicable, to identify the Borrower in accordance with the Patriot Act. The Borrower shall provide, to the extent commercially reasonable, such information and take such actions as are reasonably requested by the Agent or any Lenders in order to assist the Agent and the Lenders in maintaining compliance with the Patriot Act.

SECTION 8.13.  Judgment. (a)  If for the purposes of obtaining judgment in any court it is necessary to convert a sum due hereunder in U.S. dollars into another currency, the parties hereto agree, to the fullest extent that they may effectively do so, that the rate of exchange used shall be that at which in accordance with normal banking procedures the Agent could purchase U.S. dollars with such other currency at Citibank’s principal office in London at 11:00 A.M. (London time) on the Business Day preceding that on which final judgment is given.

(b)           The obligation of the Borrower in respect of any sum due from it in any currency (the “Primary Currency”) to any Lender or the Agent hereunder shall, notwithstanding any judgment in any other currency, be discharged only to the extent that on the Business Day following receipt by such Lender or the Agent (as the case may be), of any sum adjudged to be so due in such other currency, such Lender or the Agent (as the case may be) may in accordance with normal banking procedures purchase the applicable Primary Currency with such other currency; if the amount of the applicable Primary Currency so purchased is less than such sum due to such Lender or the Agent (as the case may be) in the applicable Primary Currency, the Borrower agrees, as a separate obligation and notwithstanding any such judgment, to indemnify such Lender or the Agent (as the case may be) against such loss, and if the amount of the applicable Primary Currency so purchased exceeds such sum due to any Lender or the Agent (as the case may be) in the applicable Primary Currency, such Lender or the Agent (as the case may be) agrees to remit to the Borrower such excess.

SECTION 8.14.  Non-Recourse to the General Partner and Associated Persons.  The Agent and each Lender agrees on behalf of itself and its successors, assigns and legal representatives, that neither the General Partner nor any Person which is a partner, shareholder, member, owner, officer, director, supervisor, trustee or other principal (collectively, “Associated Persons”) of the Borrower, the General Partner, or any of their respective successors or assigns, shall have any personal liability for the payment or performance of any of the Borrower’s obligations hereunder or under any of the Notes and no monetary or other judgment shall be sought or enforced against the General Partner or any of such Associated Persons or any of their respective successors or assigns. Notwithstanding the foregoing, neither the Agent nor any Lender shall be deemed barred by this Section 8.14 from asserting any claim against any Person based upon an allegation of fraud or misrepresentation.

SECTION 8.15.  Waiver of Jury Trial.  Each of the Borrower, the Agent and the Lenders hereby irrevocably waives all right to trial by jury in any action, proceeding or counterclaim (whether based on contract, tort or otherwise) arising out of or relating to this Agreement or the Notes or the actions of the Agent or any Lender in the negotiation, administration, performance or enforcement thereof.

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed by their respective officers thereunto duly authorized, as of the date first above written.

SCHEDULE I

TC PIPELINES, LP

CREDIT AGREEMENT

APPLICABLE LENDING OFFICES

Schedule 3.01(b)

Disclosed Litigation

On February 15, 2006, Northern Border Partners, L.P. (“Northern Border”)and ONEOK, Inc. issued a joint press release announcing certain transactions relating to (1) the sale of certain assets by ONEOK to Northern Border, (2) the increase of ONEOK’s general partnership interest in Northern Border to 100% and (3) the sale by Northern Border of 20% of its interest in Northern Border Pipeline Company to TC PipeLines Intermediate Limited Partnership (collectively, the “Transactions”).

On March 2, 2006, a holder of limited partnership units of Northern Border filed a class action and derivative complaint, Civil Action No. 1973-N, in the New Castle County Chancery Court in the State of Delaware, on behalf of a putative class of all holders of limited partnership units against Northern Border, ONEOK, Northern Plains Natural Gas Company, LLC, and related entities involved in the Transactions. The plaintiff claims the Transactions will constitute a breach of Northern Border’s partnership agreement and a breach of defendants’ fiduciary duties. The plaintiff seeks to enjoin the Transactions or to rescind the Transactions if the Transactions are completed prior to entry of a final judgment in the case. The plaintiff also seeks to recover on behalf of the class damages for the profits and any special benefits obtained by the defendants, as well as interest, costs, and attorney and expert fees.

Schedule 5.02(a)

Existing Liens

None

EXHIBIT A - FORM OF

PROMISSORY NOTE

FOR VALUE RECEIVED, the undersigned, TC PIPELINES, LP, a Delaware limited partnership (the “Borrower”) by its General Partner TC PipeLines GP, Inc., a Delaware corporation, HEREBY PROMISES TO PAY to                                             or its registered assigns (the “Lender”) for the account of its Applicable Lending Office (as defined in the Credit Agreement referred to below) the aggregate principal amount of the Advances (as defined below) owing to the Lender by the Borrower pursuant to the Credit Agreement dated as of March 31, 2006 among the Borrower, the Lender and certain other lenders parties thereto, and Citicorp North America, Inc., as Agent for the Lender and such other lenders (as amended or modified from time to time, the “Credit Agreement”); the terms defined therein being used herein as therein defined) on the date specified in the Credit Agreement.

The Borrower promises to pay interest on the unpaid principal amount of each Advance from the date of such Advance until such principal amount is paid in full, at such interest rates, and payable at such times, as are specified in the Credit Agreement.

Both principal and interest are payable in lawful money of the United States of America to CNAI, as Agent, at 388 Greenwich Street, New York, New York 10013, in same day funds. Each Advance owing to the Lender by the Borrower and the maturity thereof, and all payments made on account of principal thereof, shall be recorded by the Lender and, prior to any transfer hereof, endorsed on the grid attached hereto, which is part of this Promissory Note.

This Promissory Note is one of the Notes referred to in, and is entitled to the benefits of, the Credit Agreement. The Credit Agreement, among other things, (i) provides for the making of advances (the “Advances”) by the Lender to the Borrower in an amount not to exceed the U.S. dollar amount first above mentioned, the indebtedness of the Borrower resulting from such Advances being evidenced by this Promissory Note, and (ii) contains provisions for acceleration of the maturity hereof upon the happening of certain stated events and also for prepayments on account of principal hereof prior to the maturity hereof upon the terms and conditions therein specified. Any transfer of all or a portion of this Promissory Note shall be made only in accordance with the terms and conditions of Section 8.07 of the Credit Agreement and the Assignment and Acceptance attached to the Credit Agreement.

ADVANCES AND PAYMENTS OF PRINCIPAL

EXHIBIT B - FORM OF NOTICE OF

BORROWING

Citicorp North America, Inc., as Agent

for the Lenders parties

to the Credit Agreement

referred to below

Two Penns Way

New Castle, Delaware 19720

[Date]

Attention: Bank Loan Syndications Department

Ladies and Gentlemen:

The undersigned, TC Pipelines, LP, by its General Partner TC PipeLines GP, Inc., refers to the Credit Agreement, dated as of March 31, 2006 (as amended or modified from time to time, the “Credit Agreement”, the terms defined therein being used herein as therein defined), among the undersigned, certain Lenders parties thereto and  Citicorp North America, Inc., as Agent for said Lenders, and hereby gives you notice, irrevocably, pursuant to Section 2.02 of the Credit Agreement that the undersigned hereby requests a Borrowing under the Credit Agreement, and in that connection sets forth below the information relating to such Borrowing (the “Proposed Borrowing”) as required by Section 2.02(a) of the Credit Agreement:

(i)            The Business Day of the Proposed Borrowing is                             , 200   .

(ii)           The Type of Advances comprising the Proposed Borrowing is [Base Rate Advances] [Eurodollar Rate Advances].

(iii)          The aggregate amount of the Proposed Borrowing is $                              .

[(iv)         The initial Interest Period for each Eurodollar Rate Advance made as part of the Proposed Borrowing is                   month[s].]

The undersigned hereby certifies that the following statements are true on the date hereof, and will be true on the date of the Proposed Borrowing:

(A)          the representations and warranties contained in Section 4.01 of the Credit Agreement are correct, before and after giving effect to the Proposed Borrowing and to the application of the proceeds therefrom, as though made on and as of such date; and

(B)           no event has occurred and is continuing, or would result from such Proposed Borrowing or from the application of the proceeds therefrom, that constitutes a Default.

EXHIBIT C - FORM OF

ASSIGNMENT AND ACCEPTANCE

Reference is made to the Credit Agreement dated as of March 31, 2006 (as amended or modified from time to time, the “Credit Agreement”) among TC Pipelines, LP, a Delaware limited partnership (the “Borrower”) by its General Partner TC PipeLines GP, Inc., the Lenders (as defined in the Credit Agreement) and Citicorp North America, Inc., as agent for the Lenders (the “Agent”). Terms defined in the Credit Agreement are used herein with the same meaning.

The “Assignor” and the “Assignee” referred to on Schedule I hereto agree as follows:

1.             The Assignor hereby sells and assigns to the Assignee, and the Assignee hereby purchases and assumes from the Assignor, an interest in and to the Assignor’s rights and obligations under the Credit Agreement as of the date hereof equal to the percentage interest specified on Schedule 1 hereto of all outstanding rights and obligations under the Credit Agreement. After giving effect to such sale and assignment, the Assignee’s Commitments and the amount of the Advances owing to the Assignee will be as set forth on Schedule 1 hereto.

2.             The Assignor (i) represents and warrants that it is the legal and beneficial owner of the interest being assigned by it hereunder and that such interest is free and clear of any adverse claim; (ii) makes no representation or warranty and assumes no responsibility with respect to any statements, warranties or representations made in or in connection with the Credit Agreement or the execution, legality, validity, enforceability, genuineness, sufficiency or value of the Credit Agreement or any other instrument or document furnished pursuant thereto; (iii) makes no representation or warranty and assumes no responsibility with respect to the financial condition of the Borrower or the performance or observance by the Borrower of any of its obligations under the Credit Agreement or any other instrument or document furnished pursuant thereto; and (iv) attaches the Note, if any held by the Assignor and requests that the Agent exchange such Note for a new Note payable to the order of the Assignee in an amount equal to the Commitment assumed by the Assignee pursuant hereto or new Notes payable to the order of the Assignee in an amount equal to the Commitment assumed by the Assignee pursuant hereto and the Assignor in an amount equal to the Commitment retained by the Assignor under the Credit Agreement, respectively, as specified on Schedule 1 hereto.

3.             The Assignee (i) confirms that it has received a copy of the Credit Agreement, together with copies of the financial statements referred to in Section 4.01 thereof and such other documents and information as it has deemed appropriate to make its own credit analysis and decision to enter into this Assignment and Acceptance; (ii) agrees that it will, independently and without reliance upon the Agent, the Assignor or any other Lender and based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under the Credit Agreement; (iii) confirms that it is an Eligible Assignee; (iv) appoints and authorizes the Agent to take such action as agent on its behalf and to exercise such powers and discretion under the Credit Agreement as are delegated to the Agent by the terms thereof, together with such powers and discretion as are reasonably incidental thereto; (v) agrees that it will perform in accordance with their terms all of the obligations that by the terms of the Credit Agreement are required to be performed by it as a Lender; and (vi) attaches any U.S. Internal Revenue Service forms required under Section 2.13 of the Credit Agreement.

4.             Following the execution of this Assignment and Acceptance, it will be delivered to the Agent for acceptance and recording by the Agent. The effective date for this Assignment and Acceptance (the “Effective Date”) shall be the date of acceptance hereof by the Agent, unless otherwise specified on Schedule 1 hereto.

5.             Upon such acceptance and recording by the Agent in the Register and, if applicable issuance of a new Note to the Assignee pursuant to Section 2 hereof, as of the Effective Date, (i) the Assignee shall be a party to the Credit Agreement and, to the extent provided in this Assignment and Acceptance, have the rights

and obligations of a Lender thereunder and (ii) the Assignor shall, to the extent provided in this Assignment and Acceptance, relinquish its rights and be released from its obligations under the Credit Agreement.

6.             Upon such acceptance and recording by the Agent, from and after the Effective Date, the Agent shall make all payments under the Credit Agreement and the Notes in respect of the interest assigned hereby (including, without limitation, all payments of principal, interest and fees with respect thereto) to the Assignee. The Assignor and Assignee shall make all appropriate adjustments in payments under the Credit Agreement and the Notes for periods prior to the Effective Date directly between themselves.

7.             This Assignment and Acceptance shall be governed by, and construed in accordance with, the laws of the State of New York.

8.             This Assignment and Acceptance may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement. Delivery of an executed counterpart of Schedule 1 to this Assignment and Acceptance by telecopier shall be effective as delivery of a manually executed counterpart of this Assignment and Acceptance.

IN WITNESS WHEREOF, the Assignor and the Assignee have caused Schedule 1 to this Assignment and Acceptance to be executed by their officers thereunto duly authorized as of the date specified thereon.

Schedule 1

to

Assignment and Acceptance

*              This date should be no earlier than five Business Days after the delivery of this Assignment and Acceptance to the Agent.

EXHIBIT D - FORM OF

OPINION OF COUNSEL

FOR THE BORROWER

[Effective Date]

To each of the Lenders parties

to the Credit Agreement dated

as of March 31, 2006

among TC Pipelines, LP,

said Lenders and Citicorp North America, Inc.,

as Agent for said Lenders, and

to Citicorp North America, Inc., as Agent

TC Pipelines, LP

Ladies and Gentlemen:

Representation

This opinion is furnished to you pursuant to Section 3.01(h)(iv) of the Credit Agreement, dated as of April      , 2006 (the “Credit Agreement”), among TC Pipelines, LP (the “Borrower”) by its General Partner TC PipeLines GP, Inc. (the “GP”), the Lenders parties thereto and Citicorp North America, Inc., as Agent for said Lenders. Terms defined in the Credit Agreement are used herein as therein defined.

We have acted as special counsel for the Borrower in connection with the preparation, execution and delivery of the Credit Agreement.

Documents Reviewed

In that connection, we have examined:

(1)           The Credit Agreement.

(2)           The documents furnished by the Borrower pursuant to Article III of the Credit Agreement.

(3)           The Certificate of Limited Partnership and Amended and Restated Limited Partnership Agreement of the Borrower and all amendments thereto (the “Charter”).

(4)           A certificate of the Secretary of State of Delaware, dated April      , 2006, attesting to the continued partnership existence and good standing of the Borrower in that State (the “Good Standing Certificate”).

We have also examined the originals, or copies certified to our satisfaction, of the documents listed in a certificate of the President of the GP on behalf of the Borrower, dated the date hereof (the “Certificate”), certifying, among other things, that the documents listed in such certificate are all of the indentures, loan or credit agreements, leases, guarantees, mortgages, security agreements, bonds, notes and other agreements or instruments, and all of the orders, writs, judgments, awards, injunctions and decrees, that affect or purport to affect the Borrower’s right to borrow

money or the Borrower’s obligations under the Credit Agreement or the Notes. In addition, we have examined the originals, or copies certified to our satisfaction, of such other partnership records of the Borrower, certificates of public officials and of officers of the Borrower, and agreements, instruments and other documents, as we have deemed necessary as a basis for the opinions expressed below. As to questions of fact material to such opinions, we have relied upon certificates of the Borrower or its officers or of public officials.

Opinion

Based on the foregoing, having regard for the legal considerations that we deem relevant, and subject to the qualifications, assumptions and exceptions stated herein, we are of the following opinion:

1.             The Borrower is a limited partnership duly formed, validly existing and in good standing under the laws of the State of Delaware. The Borrower has taken all necessary partnership action to authorize the execution, delivery and performance by the Borrower of the Credit Agreement and the Notes (collectively, the “Credit Documents”).

2.             The execution, delivery and performance by the Borrower of the Credit Documents, and the consummation of the transactions contemplated thereby, are within the Borrower’s partnership powers, have been duly authorized by all necessary partnership action, and do not violate (i) the Charter or (ii) assuming that the proceeds of extensions of credit will be used in accordance with the terms of the Credit Agreement, any United States federal or State of New York law, rule or regulation applicable to the Borrower (including, without limitation, Regulation X of the Board of Governors of the Federal Reserve System) or (iii) any contractual or legal restriction contained in any document listed in the Certificate.

3.             No authorization, approval or other action by, and no notice to or filing with, any United States federal or State of New York governmental authority or regulatory body is required for the due execution, delivery and performance by the Borrower of the Credit Documents.

4.             The Credit Agreement is, and after giving effect to the initial Borrowing, the Notes will be, valid and binding obligations of the Borrower enforceable against the Borrower in accordance with their respective terms.

Negative Assurance

In addition, we advise you supplementally as a matter of fact and not opinion that based solely upon certifications contained in the Certificate, except to the extent set forth in the Certificate, to our knowledge, there are no pending or overtly threatened actions or proceedings against the Borrower or any of its Subsidiaries before any court, governmental agency or arbitrator that purport to affect the legality, validity, binding effect or enforceability of the Credit Agreement or any of the Notes or the consummation of the transactions contemplated thereby or that are likely to have a materially adverse effect upon the financial condition or operations of the Borrower or any of its Subsidiaries.

Assumptions, Qualifications and Exceptions

In rendering these opinions, we have, with your permission, assumed the following: (i) the authenticity of original documents and the genuineness of all signatures, and the conformity to the originals of all documents submitted to us as copies; (ii) the truth, accuracy and completeness of the information, representations and warranties contained in the records, documents, instruments and certificates we have reviewed; (iii) your due organization, valid existence and good standing; (iv) your due authorization, execution and delivery of the Credit Agreement; (v) the valid and binding effect of the Credit Agreement on, and the enforceability of the Credit Agreement against, you; (vi) the absence of any evidence extrinsic to the provisions of the written agreements among the parties that the parties intended a meaning contrary to that expressed by those provisions; and (vii) there has not been any mutual mistake of fact, fraud, duress or undue influence.

Our opinion in paragraph 1 that the Borrower is in good standing is based solely upon our review of the Good Standing Certificate. In rendering our opinions with respect to contractual obligations, we have assumed that the governing law of each contractual obligation is New York; and we have not reviewed the covenants in the contractual obligations that contain financial ratios or other similar financial restrictions, and no opinion is provided with respect thereto.

Certain Limitations and Qualifications

Whenever a statement herein is qualified by the phrases “known to us” or “to our knowledge,” it is intended to indicate that, during the course of our representation on behalf of the Borrower in this transaction, no information that would give us current actual knowledge of the inaccuracy of such statement has come to the attention of the attorneys presently in the firm who have rendered legal service in connection with our representation of the Borrower in this transaction. However, we have not undertaken any independent investigation or review to determine the accuracy of any such statement, and any limited inquiry undertaken by us during the preparation of this opinion letter should not be regarded as such an investigation or review; no inference as to our knowledge of any matters bearing on the accuracy of any such statement should be drawn from the fact of our representation on behalf of the Borrower in this transaction.

Our opinions are limited to the laws of the State of New York, the Delaware Revised Uniform Partnership Act and the federal laws of the United States. We express no opinion as to whether the laws of any particular jurisdiction apply, and no opinion to the extent that the laws of any jurisdiction other than those identified above are applicable to the Credit Agreement or the Notes or the transactions contemplated thereby. As you know, we are not licensed to practice law in the State of Delaware, and our opinions herein with respect to the partnership law of Delaware are based solely on our review of the Delaware Revised Uniform Partnership Act as found in a standard compilation of the official statutes of the State of Delaware.

Our opinion that any document is valid, binding or enforceable in accordance with its terms is qualified as to:

(a)           limitations imposed by bankruptcy, insolvency, reorganization, arrangement, fraudulent conveyance, moratorium, or other laws relating to or affecting the rights of creditors generally;

(b)           the unenforceability under certain circumstances of provisions imposing penalties, forfeiture, late payment charges, or an increase in interest rate upon delinquency in payment or the occurrence of any event of default; and

(c)           general principles of equity, including without limitation concepts of materiality, reasonableness, good faith and fair dealing, and the possible unavailability of specific performance or injunctive relief, regardless of whether such enforceability is considered in a proceeding in equity or at law.

Use of Opinion

This opinion letter is rendered to you solely for your benefit and the benefit of your permitted successors and assigns pursuant to the Credit Agreement in connection with the transaction covered in the first paragraph of this opinion letter and may not be relied upon or used by, circulated, quoted or referred to, nor may copies hereof be delivered to, any other person without our prior written approval, except that copies of this opinion letter may be furnished to your independent auditors and legal counsel in connection with their providing advice to you regarding such transaction and to your appropriate regulatory authorities or pursuant to an order or legal process of any relevant governmental authority and to your permitted successors and assigns and prospective successors and assigns. We disclaim any obligation to update this opinion letter for events occurring or coming to our attention after the date hereof.

Very truly yours,

ORRICK, HERRINGTON & SUTCLIFFE LLP