6,000,000 Shares PRA INTERNATIONAL Common Stock FORM OF UNDERWRITING AGREEMENT

Exhibit 1.1

6,000,000 Shares

PRA INTERNATIONAL

Common Stock

FORM OF UNDERWRITING AGREEMENT

May    , 2005

Dear Sirs:

     1. Introductory. The stockholders listed in Schedule A hereto (“Selling Stockholders”) propose severally to sell an aggregate of 6,000,000 outstanding shares (“Firm Securities”) of the common stock, par value $0.01 per share (“Securities”) of PRA International, a Delaware corporation (the “Company”), and the Selling Stockholders also propose to sell to the Underwriters, at the option of the Underwriters, an aggregate of not more than 900,000 additional outstanding shares (“Optional Securities”) of the Company’s Securities as set forth below. The Firm Securities and the Optional Securities are herein collectively called the “Offered Securities”. The Company and the Selling Stockholders hereby agree with the several Underwriters named in Schedule B hereto (“Underwriters”) as follows:

     2. Representations and Warranties of the Company and the Selling Stockholders. (a) The Company represents and warrants to, and agrees with, the several Underwriters that:

     (i) A registration statement (No. 333-124981) relating to the Offered Securities, including a form of prospectus, has been filed with the Securities and Exchange Commission (“Commission”) and either (A) has been declared effective under the Securities Act of 1933 (“Securities Act”) and is not proposed to be amended or (B) is proposed to be amended by amendment or post-effective amendment. If such registration statement (the “initial registration statement”) has been declared effective, either (A) an additional registration statement (the “additional registration statement”) relating to the Offered Securities may have been filed with the Commission pursuant to Rule 462(b) (“Rule 462(b)”) under the Securities Act and, if so filed, has become effective upon filing pursuant to such Rule and the Offered Securities all have been duly registered under the Securities Act pursuant to the initial registration statement and, if applicable, the additional registration statement or (B) such an additional registration statement is proposed to be filed with the Commission pursuant to Rule 462(b) and will become effective upon filing pursuant to such Rule and upon such filing the Offered Securities will all have been duly registered under the Securities Act pursuant to the initial registration statement and such additional registration statement. If the Company does not propose to amend the initial registration statement or if an additional registration statement has been filed and the Company does not propose to amend it, and if any post-effective amendment to either such registration statement has been filed with the Commission prior to the execution and delivery of this Agreement, the most recent amendment (if any) to each such registration statement has been declared effective by the Commission or has become effective upon filing pursuant to Rule 462(c) (“Rule 462(c)”) under the Securities Act or, in the case of the additional registration statement, Rule 462(b). For purposes of this Agreement, “Effective Time” with respect to the initial registration statement or, if filed prior to the execution and delivery of this Agreement, the additional registration statement

means (A) if the Company has advised the Representatives that it does not propose to amend such registration statement, the date and time as of which such registration statement, or the most recent post-effective amendment thereto (if any) filed prior to the execution and delivery of this Agreement, was declared effective by the Commission or has become effective upon filing pursuant to Rule 462(c), or (B) if the Company has advised the Representatives that it proposes to file an amendment or post-effective amendment to such registration statement, the date and time as of which such registration statement, as amended by such amendment or post-effective amendment, as the case may be, is declared effective by the Commission. If an additional registration statement has not been filed prior to the execution and delivery of this Agreement but the Company has advised the Representatives that it proposes to file one, “Effective Time” with respect to such additional registration statement means the date and time as of which such registration statement is filed and becomes effective pursuant to Rule 462(b). “Effective Date” with respect to the initial registration statement or the additional registration statement (if any) means the date of the Effective Time thereof. The initial registration statement, as amended at its Effective Time, including all information contained in the additional registration statement (if any) and deemed to be a part of the initial registration statement as of the Effective Time of the additional registration statement pursuant to the General Instructions of the Form on which it is filed and including all information (if any) deemed to be a part of the initial registration statement as of its Effective Time pursuant to Rule 430A(b) (“Rule 430A(b)”) under the Securities Act, is hereinafter referred to as the “Initial Registration Statement”. The additional registration statement, as amended at its Effective Time, including the contents of the initial registration statement incorporated by reference therein and including all information (if any) deemed to be a part of the additional registration statement as of its Effective Time pursuant to Rule 430A(b), is hereinafter referred to as the “Additional Registration Statement”. The Initial Registration Statement and the Additional Registration Statement are hereinafter referred to collectively as the “Registration Statements” and individually as a “Registration Statement”. The form of prospectus relating to the Offered Securities, as first filed with the Commission pursuant to and in accordance with Rule 424(b) (“Rule 424(b)”) under the Securities Act or (if no such filing is required) as included in a Registration Statement, is hereinafter referred to as the “Prospectus”. No document has been or will be prepared or distributed in reliance on Rule 434 under the Securities Act.

     (ii) If the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement: (A) on the Effective Date of the Initial Registration Statement, the Initial Registration Statement conformed in all material respects to the requirements of the Securities Act and the rules and regulations of the Commission (“Rules and Regulations”) and did not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, (B) on the Effective Date of the Additional Registration Statement (if any), each Registration Statement conformed or will conform, in all material respects to the requirements of the Securities Act and the Rules and Regulations and did not include, or will not include, any untrue statement of a material fact and did not omit, or will not omit, to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and (C) on the date of this Agreement, the Initial Registration Statement and, if the Effective Time of the Additional Registration Statement is prior to the execution and delivery of this Agreement, the Additional Registration Statement each conforms, and at the time of filing of the Prospectus pursuant to Rule 424(b) or (if no such filing is required) at the Effective Date of the Additional Registration Statement in which the Prospectus is included, each Registration Statement and the Prospectus will conform, in all material respects to the requirements of the Securities Act and the Rules and Regulations, and neither of such documents includes, or will include, any untrue statement of a material fact or omits, or will omit, to state any material fact required to be stated therein or necessary to make the statements therein not misleading. If the Effective Time of the Initial Registration Statement is subsequent to the execution and delivery of this Agreement: on the Effective Date of the Initial Registration Statement, the Initial Registration Statement and the Prospectus will conform in all material respects to the requirements of the Securities Act and the Rules and Regulations, neither of such

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documents will include any untrue statement of a material fact or will omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and no Additional Registration Statement has been or will be filed. The two preceding sentences do not apply to statements in or omissions from a Registration Statement or the Prospectus based upon written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information is that described as such in Section 7(c) hereof.

     (iii) The Company has been duly incorporated and is an existing corporation in good standing under the laws of the State of Delaware, with power and authority (corporate and other) to own its properties and conduct its business as described in the Prospectus; and the Company is duly qualified to do business as a foreign corporation in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified or in good standing would not have a material adverse effect on the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole (“Material Adverse Effect”).

     (iv) Each subsidiary of the Company required to be identified in the Registration Statement pursuant to Item 601(b)(21) of Regulation S-K under the Securities Act has been duly incorporated and is an existing corporation in good standing under the laws of the jurisdiction of its incorporation, with power and authority (corporate and other) to own its properties and conduct its business as described in the Prospectus, except where the failure to be in good standing would not have a Material Adverse Effect; and each subsidiary of the Company is duly qualified to do business as a foreign corporation in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure to be so qualified would not have a Material Adverse Effect; all of the issued and outstanding capital stock of each subsidiary of the Company has been duly authorized and validly issued and is fully paid and nonassessable; and the capital stock of each subsidiary owned by the Company, directly or through subsidiaries, is owned free from liens, encumbrances and defects, except pursuant to the Company’s senior credit facility described in the Prospectus.

     (v) The Offered Securities and all other outstanding shares of capital stock of the Company have been duly authorized, validly issued, fully paid and nonassessable and conform to the description thereof contained in the Prospectus; and the stockholders of the Company have no preemptive rights with respect to the Securities.

     (vi) Except as disclosed in the Prospectus, there are no contracts, agreements or understandings between the Company and any person that would give rise to a valid claim against the Company or any Underwriter for a brokerage commission, finder’s fee or other like payment in connection with this offering.

     (vii) Except as disclosed in the Prospectus, there are no contracts, agreements or understandings between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to a Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Securities Act.

     (viii) The Securities have been approved for listing on The Nasdaq Stock Market’s National Market.

     (ix) No consent, approval, authorization, or order of, or filing with, any governmental agency or body or any court is required to be obtained or made by the Company for the consummation of the transactions contemplated by this Agreement in connection with the sale of the Offered Securities, except (i) such as have been obtained and made under the Securities Act;

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(ii) such as have been obtained and made by the Underwriters with the National Association of Securities Dealers, Inc. (“NASD”) in connection with the Offered Securities; and (iii) such as may be required under state securities laws.

     (x) The execution, delivery and performance of this Agreement, and the consummation of the transactions herein contemplated will not result in a breach or violation of any of the terms and provisions of, or constitute a default under, any statute, any rule, regulation or order of any governmental agency or body or any court, domestic or foreign, having jurisdiction over the Company or any subsidiary of the Company or any of their properties, or any agreement or instrument to which the Company or any such subsidiary is a party or by which the Company or any such subsidiary is bound or to which any of the properties of the Company or any such subsidiary is subject, or the charter or by-laws of the Company or any such subsidiary, and the Company has full power and authority to authorize, issue and sell the Offered Securities as contemplated by this Agreement.

     (xi) This Agreement has been duly authorized, executed and delivered by the Company.

     (xii) Except as disclosed in the Prospectus, the Company and its subsidiaries have good and marketable title to all real properties and all other properties and assets owned by them, in each case free from liens, encumbrances and defects that would materially affect the value thereof or materially interfere with the use made or to be made thereof by them; and except as disclosed in the Prospectus, the Company and its subsidiaries hold any leased real or personal property under valid and enforceable leases with no exceptions that would materially interfere with the use made or to be made thereof by them.

     (xiii) The Company and its subsidiaries possess adequate certificates, authorities or permits issued by appropriate governmental agencies or bodies necessary to conduct the business now operated by them as described in the Prospectus and have not received any notice of proceedings relating to the revocation or modification of any such certificate, authority or permit that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a Material Adverse Effect.

     (xiv) No labor dispute with the employees of the Company or any subsidiary exists or, to the knowledge of the Company, is imminent that might have a Material Adverse Effect.

     (xv) The Company and its subsidiaries own, possess or can acquire on reasonable terms, adequate trademarks, trade names and other rights to inventions, know-how, patents, copyrights, confidential information and other intellectual property (collectively, “intellectual property rights”) necessary to conduct in all material respects the business now operated by them, or presently employed by them as described in the Prospectus, and have not received any notice of infringement of or conflict with asserted rights of others with respect to any intellectual property rights that could reasonably be expected to have a Material Adverse Effect.

     (xvi) Except as disclosed in the Prospectus, neither the Company nor any of its subsidiaries is in violation of any statute, any rule, regulation, decision or order of any governmental agency or body or any court, domestic or foreign, relating to the use, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “environmental laws”), owns or operates any real property contaminated with any substance that is subject to any environmental laws, is liable for any off-site disposal or contamination pursuant to any environmental laws, or is subject to any claim relating to any environmental laws, which violation, contamination, liability or claim would individually or in the aggregate have a Material Adverse Effect; and the Company is not aware of any pending investigation which might lead to such a claim.

     (xvii) Except as disclosed in the Prospectus, there are no pending actions, suits or proceedings against or affecting the Company, any of its subsidiaries or any of their respective

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properties that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a Material Adverse Effect, or would materially and adversely affect the ability of the Company to perform its obligations under this Agreement, or which are otherwise material in the context of the sale of the Offered Securities; and no such actions, suits or proceedings are threatened or, to the Company’s knowledge, contemplated.

     (xviii) The financial statements included in each Registration Statement and the Prospectus present fairly in all material respects the financial position of the Company and its consolidated subsidiaries as of the dates shown and their results of operations and cash flows for the periods shown, and such financial statements have been prepared in conformity with the generally accepted accounting principles in the United States applied on a consistent basis; all non-GAAP financial information included in each Registration Statement complies with the requirements of Regulation G and Item 10 of Regulation S-K under the Securities Act; and the schedules included in each Registration Statement present fairly in all material respects the information required to be stated therein.

     (xix) Except as disclosed in the Prospectus, since the date of the latest audited financial statements included in the Prospectus there has been no material adverse change, nor any development or event involving a prospective material adverse change, in the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole, and, except as disclosed in or contemplated by the Prospectus, there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock.

     (xx) The Company is subject to the reporting requirements of either Section 13 or Section 15(d) of the Securities Exchange Act of 1934 and files reports with the Commission on the Electronic Data Gathering, Analysis, and Retrieval (EDGAR) system.

     (xxi) The Company is not and, after giving effect to the offering and sale of the Offered Securities and the application of the proceeds thereof as described in the Prospectus, will not be an “investment company” as defined in the Investment Company Act of 1940.

     (b) Each Selling Stockholder severally and not jointly represents and warrants to, and agrees with, the several Underwriters that:

     (i) Such Selling Stockholder has and on each Closing Date hereinafter mentioned will have (in the case of Offered Securities to be issued upon exercise of options deposited with the Custodian, after giving effect to the exercise of such options pursuant to the applicable option exercise notice delivered to the Custodian and payment of the exercise price therefor, in accordance with the Custody Agreement) valid and unencumbered title to the Offered Securities to be delivered by such Selling Stockholder on such Closing Date and full right, power and authority to enter into this Agreement and to sell, assign, transfer and deliver the Offered Securities to be delivered by such Selling Stockholder on such Closing Date hereunder; and upon the delivery of and payment for the Offered Securities on each Closing Date hereunder the several Underwriters will acquire valid and unencumbered title to the Offered Securities to be delivered by such Selling Stockholder on such Closing Date.

     (ii) Such Selling Stockholder has, and on each Closing Date will have, full legal right, power and authority, and all authorization and approval required by law, to enter into the Custody Agreement (the “Custody Agreement”) signed by such Selling Stockholder and the Custodian (as defined below) relating to the deposit of the Offered Securities to be sold by such Selling Stockholder and the Power of Attorney (“Power of Attorney”) appointing Patrick K. Donnelly, J. Matthew Bond and Spiro Fotopoulos as such Selling Stockholder’s attorneys-in-fact (the “Attorneys”, and each, an “Attorney”) to the extent set forth therein and relating to the transactions contemplated hereby; and to sell, assign, transfer and deliver the Offered Securities to be sold by such Selling Stockholder in the manner provided herein and therein.

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     (iii) No consent, approval, authorization or order of, or filing with, any governmental agency or body or any court is required to be obtained or made by such Selling Stockholder for the consummation of the transactions contemplated by the Custody Agreement or this Agreement in connection with the sale of the Offered Securities sold by such Selling Stockholder, except such as have been obtained and made under the Securities Act and such as may be required under state securities laws.

     (iv) This Agreement has been duly authorized, executed and delivered by or on behalf of such Selling Stockholder.

     (v) The Power of Attorney and related Custody Agreement with respect to such Selling Stockholder have been duly authorized, executed and delivered by such Selling Stockholder and constitute valid and legally binding obligations of such Selling Stockholder enforceable in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and to general equity principles.

     (vi) The execution, delivery and performance of the Custody Agreement and this Agreement, and the consummation of the transactions herein contemplated will not result in a breach or violation of any of the terms and provisions of, or constitute a default under, any statute, any rule or regulation governing transactions of the type herein contemplated or any order applicable to such Selling Stockholder of any governmental agency or body or any court, domestic or foreign, having jurisdiction over such Selling Stockholder or any of their properties, or any agreement or instrument to which such Selling Stockholder is a party or by which such Selling Stockholder is bound or to which any of the properties of such Selling Stockholder is subject, or the charter or by-laws of such Selling Stockholder if such Selling Stockholder is a corporation, the partnership agreement of such Selling Stockholder if such Selling Stockholder is a partnership, the trust agreement of such Selling Stockholder if such Selling Stockholder is a trust or any other constituent documents of such Selling Stockholder.

     (vii) If the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement: (A) on the Effective Date of the Initial Registration Statement, the Initial Registration Statement conformed in all respects to the requirements of the Securities Act and the Rules and Regulations and did not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, (B) on the Effective Date of the Additional Registration Statement (if any), each Registration Statement conformed, or will conform, in all respects to the requirements of the Securities Act and the Rules and Regulations did not include, or will not include, any untrue statement of a material fact and did not omit, or will not omit, to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and (C) on the date of this Agreement, the Initial Registration Statement and, if the Effective Time of the Additional Registration Statement is prior to the execution and delivery of this Agreement, the Additional Registration Statement each conforms, and at the time of filing of the Prospectus pursuant to Rule 424(b) or (if no such filing is required) at the Effective Date of the Additional Registration Statement in which the Prospectus is included, each Registration Statement and the Prospectus will conform, in all respects to the requirements of the Securities Act and the Rules and Regulations, and neither of such documents includes, or will include, any untrue statement of a material fact or omits, or will omit, to state any material fact required to be stated therein or necessary to make the statements therein not misleading. If the Effective Time of the Initial Registration Statement is subsequent to the execution and delivery of this Agreement: on the Effective Date of the Initial Registration Statement, the Initial Registration Statement and the Prospectus will conform in all respects to the requirements of the Securities Act and the Rules and Regulations, neither of such documents will include any untrue statement of a material fact or will omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading. The two preceding sentences apply only to statements in or omissions from a Registration Statement or

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the Prospectus based upon written information furnished to the Company by or on behalf of such Selling Stockholder specifically for use therein.

     (viii) Except as disclosed in the Prospectus, there are no contracts, agreements or understandings between such Selling Stockholder and any person that would give rise to a valid claim against the Company or any Underwriter for a brokerage commission, finder’s fee or other like payment in connection with this offering.

     (ix) At any time during the period during which a prospectus relating to the Offered Securities is required to be delivered under the Securities Act in connection with sales by any Underwriter or dealer, if there is any change in the information referred to in Section 2(b)(vii) with respect to a Selling Stockholder, such Selling Stockholder will immediately notify the Company and the Representatives of such change.

     (x) The sale of the Offered Securities by such Selling Stockholder pursuant hereto is not prompted by any information concerning the Company or any of its subsidiaries that is not set forth in the Prospectus or any supplement thereto.

     3. Purchase, Sale and Delivery of Offered Securities. On the basis of the representations, warranties and agreements herein contained, but subject to the terms and conditions herein set forth, each Selling Stockholder agrees, severally and not jointly, to sell to each Underwriter, and each Underwriter agrees, severally and not jointly, to purchase from each Selling Stockholder, at a purchase price of $[•] per share, that number of Firm Securities (rounded up or down, as determined by the Representatives in their discretion, in order to avoid fractions) obtained by multiplying the number of Firm Securities set forth opposite the name of such Selling Stockholder in Schedule A hereto by a fraction the numerator of which is the number of Firm Securities set forth opposite the name of such Underwriter in Schedule B hereto and the denominator of which is the total number of Firm Securities.

     Option exercise notices and/or certificates in negotiable form for the Offered Securities to be sold by the Selling Stockholders hereunder have been placed in custody, for delivery under this Agreement, under Custody Agreements made with Wachovia Bank, N.A., as custodian (in such capacity, the “Custodian”). Each Selling Stockholder agrees that the option exercise notices and the shares represented by the certificates (including shares issuable upon exercise of options pursuant to such option exercise notices) held in custody for the Selling Stockholders under such Custody Agreements are subject to the interests of the Underwriters hereunder, that the arrangements made by the Selling Stockholders for such custody are to that extent irrevocable, and that the obligations of the Selling Stockholders hereunder shall not be terminated by operation of law, whether by the death of any individual Selling Stockholder or the occurrence of any other event, or in the case of a trust, by the death of any trustee or trustees or the termination of such trust. If any individual Selling Stockholder or any such trustee or trustees should die, or if any other such event should occur, or if any of such trusts should terminate, before the delivery of the Offered Securities hereunder, certificates for such Offered Securities shall be delivered by the Custodian in accordance with the terms and conditions of this Agreement as if such death or other event or termination had not occurred, regardless of whether or not the Custodian shall have received notice of such death or other event or termination.

     The Custodian will deliver the Firm Securities to the Representatives for the accounts of the Underwriters, against payment of the purchase price in Federal (same day) funds by official bank check or checks or wire transfer to an account at a bank acceptable to the Representatives drawn to the order of the Custodian, for the account of each of the Selling Stockholders, at the office of Cravath, Swaine & Moore LLP, at 10:00 A.M., New York time, on June [•], 2005, or at such other time not later than seven full business days thereafter as the Representatives and the Custodian determine, such time being herein referred to as the “First Closing Date”. For purposes of Rule 15c6-1 under the Securities Exchange Act of 1934 (the “Exchange Act”), the First Closing Date (if later than the otherwise applicable settlement date) shall be the settlement date for payment of funds and delivery of securities for all the Offered Securities sold pursuant to the offering. The certificates for the Firm Securities so to be delivered will be in definitive

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form, in such denominations and registered in such names as the Representatives request and will be made available for checking and packaging at the office of Cravath, Swaine & Moore LLP at least 24 hours prior to the First Closing Date.

     In addition, upon written notice from the Representatives given to the Company and the Selling Stockholders from time to time not more than 30 days subsequent to the date of the Prospectus, the Underwriters may purchase all or less than all of the Optional Securities at the purchase price per Security to be paid for the Firm Securities. The Selling Stockholders agree, severally and not jointly, to sell to the Underwriters the respective numbers of Optional Securities obtained by multiplying the number of Optional Securities specified in such notice by a fraction the numerator of which is the number of shares set forth opposite the names of such Selling Stockholders in Schedule A hereto under the caption “Number of Optional Securities to be Sold” and the denominator of which is the total number of Optional Securities (subject to adjustment by the Representatives to eliminate fractions). Such Optional Securities shall be purchased from each Selling Stockholder for the account of each Underwriter in the same proportion as the number of Firm Securities set forth opposite such Underwriter’s name bears to the total number of Firm Securities (subject to adjustment by the Representatives to eliminate fractions) and may be purchased by the Underwriters only for the purpose of covering over-allotments made in connection with the sale of the Firm Securities. No Optional Securities shall be sold or delivered unless the Firm Securities previously have been, or simultaneously are, sold and delivered. The right to purchase the Optional Securities or any portion thereof may be exercised from time to time and to the extent not previously exercised may be surrendered and terminated at any time upon notice by the Representatives to the Selling Stockholders.

     Each time for the delivery of and payment for the Optional Securities, being herein referred to as an “Optional Closing Date”, which may be the First Closing Date (the First Closing Date and each Optional Closing Date, if any, being sometimes referred to as a “Closing Date”), shall be determined by the Representatives but shall be not later than five full business days after written notice of election to purchase Optional Securities is given. The Custodian will deliver the Optional Securities being purchased on each Optional Closing Date to the Representatives for the accounts of the several Underwriters, against payment of the purchase price therefor in Federal (same day) funds by official bank check or checks or wire transfer to an account at a bank acceptable to the Representatives drawn to the order of [•], for the account of each of the Selling Stockholders at the office of Cravath, Swaine & Moore LLP. The certificates for the Optional Securities being purchased on each Optional Closing Date will be in definitive form, in such denominations and registered in such names as the Representatives request upon reasonable notice prior to such Optional Closing Date and will be made available for checking and packaging at the office of Cravath, Swaine & Moore LLP at a reasonable time in advance of such Optional Closing Date.

     4. Offering by Underwriters. It is understood that the several Underwriters propose to offer the Offered Securities for sale to the public as set forth in the Prospectus.

     5. Certain Agreements of the Company and the Selling Stockholders. The Company agrees with the several Underwriters and the Selling Stockholders that:

     (a) If the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement, the Company will file the Prospectus with the Commission pursuant to and in accordance with subparagraph (1) (or, if applicable and if consented to by the Representatives, subparagraph (4)) of Rule 424(b) not later than the earlier of (A) the second business day following the execution and delivery of this Agreement or (B) the fifteenth business day after the Effective Date of the Initial Registration Statement.

          The Company will advise the Representatives promptly of any such filing pursuant to Rule 424(b). If the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement and an additional registration statement is necessary to register a portion of the Offered Securities under the Securities Act but the Effective Time thereof has not occurred as of such execution and delivery, the Company will file the additional registration statement or, if filed, will file a post-

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effective amendment thereto with the Commission pursuant to and in accordance with Rule 462(b) on or prior to 10:00 P.M., New York time, on the date of this Agreement or, if earlier, on or prior to the time the Prospectus is printed and distributed to any Underwriter, or will make such filing at such later date as shall have been consented to by the Representatives.

     (b) The Company will advise the Representatives promptly of any proposal to amend or supplement the initial or any additional registration statement as filed or the related prospectus or the Initial Registration Statement, the Additional Registration Statement (if any) or the Prospectus and will not effect such amendment or supplementation without the Representatives’ consent, which consent shall not be unreasonably withheld; and the Company will also advise the Representatives promptly of the effectiveness of each Registration Statement (if its Effective Time is subsequent to the execution and delivery of this Agreement) and of any amendment or supplementation of a Registration Statement or the Prospectus and of the institution by the Commission of any stop order proceedings in respect of a Registration Statement and will use its best efforts to prevent the issuance of any such stop order and to obtain as soon as possible its lifting, if issued.

     (c) If, at any time when a prospectus relating to the Offered Securities is required to be delivered under the Securities Act in connection with sales by any Underwriter or dealer, any event occurs as a result of which the Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, or if it is necessary at any time to amend the Prospectus to comply with the Securities Act, the Company will promptly notify the Representatives of such event and will promptly prepare and file with the Commission, at its own expense, an amendment or supplement which will correct such statement or omission or an amendment which will effect such compliance. Neither the Representatives’ consent to, nor the Underwriters’ delivery of, any such amendment or supplement shall constitute a waiver of any of the conditions set forth in Section 6.

     (d) As soon as practicable, but not later than the Availability Date (as defined below), the Company will make generally available to its securityholders an earnings statement covering a period of at least 12 months beginning after the Effective Date of the Initial Registration Statement (or, if later, the Effective Date of the Additional Registration Statement) which will satisfy the provisions of Section 11(a) of the Securities Act. For the purpose of the preceding sentence, “Availability Date” means the 45th day after the end of the fourth fiscal quarter following the fiscal quarter that includes such Effective Date, except that, if such fourth fiscal quarter is the last quarter of the Company’s fiscal year, “Availability Date” means the 90th day after the end of such fourth fiscal quarter.

     (e) The Company will furnish to the Representatives copies of each Registration Statement (three of which will be signed and will include all exhibits), each related preliminary prospectus, and, so long as a prospectus relating to the Offered Securities is required to be delivered under the Securities Act in connection with sales by any Underwriter or dealer, the Prospectus and all amendments and supplements to such documents, in each case in such quantities as the Representatives request. The Prospectus shall be so furnished on or prior to 3:00 P.M., New York time, on the business day following the later of the execution and delivery of this Agreement or the Effective Time of the Initial Registration Statement. All other such documents shall be so furnished as soon as available. The Company will pay the expenses of printing and distributing to the Underwriters all such documents.

     (f) The Company will arrange for the qualification of the Offered Securities for sale under the laws of such jurisdictions as the Representatives designate and will continue such qualifications in effect so long as required for the distribution.

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     (g) During the period of five years hereafter, the Company will furnish to the Representatives and, upon request, to each of the other Underwriters, as soon as practicable after the end of each fiscal year, a copy of its annual report to stockholders for such year; and the Company will furnish to the Representatives (i) as soon as available, a copy of each report and any definitive proxy statement of the Company filed with the Commission under the Exchange Act or mailed to stockholders, and (ii) from time to time, such other information concerning the Company as the Representatives may reasonably request.

     (h) For the period specified below (the “Lock-Up Period”), the Company will not offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, or file with the Commission a registration statement under the Securities Act relating to, any additional shares of its Securities or securities convertible into or exchangeable or exercisable for any shares of its Securities, or publicly disclose the intention to make any such offer, sale, pledge, disposition or filing, without the prior written consent of the Representatives, except that the Company may (i) issue Securities pursuant to the conversion or exchange of convertible or exchangeable securities or the exercise of warrants or options, in each case outstanding on the date hereof; (ii) grant employee stock options or restricted stock awards or other equity awards pursuant to the terms of a plan in effect on the date hereof; (iii) issue Securities pursuant to the exercise of such options or other equity awards; (iv) issue Securities or securities convertible into or exchangeable or exercisable for Securities in connection with the acquisition by the Company of another entity, provided that each recipient of such Securities or securities convertible into or exchangeable or exercisable for Securities agrees to be bound in writing to the terms of this Section 5(h) prior to such issuance; and/or (v) file with the Commission one or more registration statements on Form S-8 registering the Securities issuable under the Company’s stock option plans in effect on the date hereof, in each case subject to no further transfer during the Lock-Up Period. The initial Lock-Up Period will commence on the date of this Agreement and continue for 90 days after the date of the public offering of the Firm Securities or such earlier date that the Representatives consent to in writing; provided, however, that for purposes of allowing the Representatives to comply with NASD Rule 2711(f)(4) and NYSE Rule 472(f)(4), if (1) during the last 17 days of the initial Lock-Up Period, the Company releases earnings results or material news or a material event relating to the Company occurs or (2) prior to the expiration of the initial Lock-Up Period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the initial Lock-Up Period, then in each case the Lock-Up Period will be extended until the expiration of the 18-day period beginning on the date of release of the earnings results or the occurrence of the material news or material event, as applicable, unless the Representatives waive, in writing, such extension.

     (i) The Company and each Selling Stockholder agree with the several Underwriters that the Company and such Selling Stockholder will pay all expenses incident to the performance of the obligations of the Company and such Selling Stockholder, as the case may be, under this Agreement, for any filing fees and other expenses (including the reasonable fees and disbursements of counsel) in connection with qualification of the Offered Securities for sale under the laws of such jurisdictions as the Representatives designate and the printing of memoranda relating thereto, for the filing fee incident to the review by the NASD of the Offered Securities, for any travel expenses of the Company’s officers and employees and any other expenses of the Company and one-half of the costs of the rental of the airplane used by the Representatives and the Company’s officers in connection with attending or hosting meetings with prospective purchasers of the Offered Securities, for any transfer taxes on the sale by the Selling Stockholders of the Offered Securities to the Underwriters and for expenses incurred in distributing preliminary prospectuses and the Prospectus (including any amendments and supplements thereto) to the Underwriters.

     (j) Each Selling Stockholder agrees, for the Lock-Up Period, not to offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, any additional shares of the Securities of the Company or securities convertible into or exchangeable or exercisable for any shares of Securities, enter into a transaction which would have the same effect, or enter into any swap, hedge or other arrangement that transfers, in whole or in part, any of the economic consequences of ownership of

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the Securities, whether any such aforementioned transaction is to be settled by delivery of the Securities or such other securities, in cash or otherwise, or publicly disclose the intention to make any such offer, sale, pledge or disposition, or enter into any such transaction, swap, hedge or other arrangement, without, in each case, the prior written consent of the Representatives; provided, that the terms of this Section 5(j) shall not apply to Securities acquired by a Selling Stockholder in the open market; provided further, that a Selling Stockholder may transfer Securities (or any securities convertible thereinto or exercisable or exchangeable therefor) to any of the following transferees who agree to be bound in writing by the terms of this Section 5(j) prior to such transfer and who receive such Securities in a transfer not involving a disposition for value: (i) any donee(s) of one or more bona fide gifts of Securities; (ii) any trust for the direct or indirect benefit of such Selling Stockholder or of any familial relation thereof not more remote than first cousin, whether by blood, marriage or adoption; (iii) any beneficiary of such Selling Stockholder pursuant to a will or other testamentary document or applicable laws of descent; and/or (iv) if such Selling Stockholder is an investment fund entity that is a limited partnership, limited liability company or equivalent foreign entity (an “Investment Fund Entity”), to any other Investment Fund Entity under the control of such Selling Stockholder or under the control of the general partner or managing member of such Selling Stockholder; and provided further, that, with respect to any Selling Stockholder that is an officer of the Company with a loan outstanding as of the date hereof and described in the Prospectus that is secured by Securities, the terms of this Section 5(j) shall not apply to (A) the pledge of Securities by such officer to secure financing in replacement of such outstanding loan or (B) the subsequent foreclosure sale of such Securities by the lender of such replacement financing in the event of a default under such replacement financing by such officer. The initial Lock-Up Period will commence on the date of this Agreement and continue for 90 days after the date of the public offering of the Firm Securities or such earlier date that the Representatives consent to in writing; provided, however, that for purposes of allowing the Representatives to comply with NASD Rule 2711(f)(4) and NYSE Rule 472(f)(4), if (1) during the last 17 days of the initial Lock-Up Period, the Company releases earnings results or material news or a material event relating to the Company occurs or (2) prior to the expiration of the initial Lock-Up Period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the initial Lock-Up Period, then in each case the Lock-Up Period will be extended until the expiration of the 18-day period beginning on the date of release of the earnings results or the occurrence of the material news or material event, as applicable, unless the Representatives waive, in writing, such extension. Nothing contained in this Section 5(j) shall limit or restrict the ability of a Selling Stockholder to exercise any options or to convert or exchange any other security into Securities, provided that any such Securities received upon such exercise of options or upon such conversion or exchange of any other security will also be subject to this Section 5(j).

     6. Conditions of the Obligations of the Underwriters. The obligations of the several Underwriters to purchase and pay for the Firm Securities on the First Closing Date and the Optional Securities to be purchased on each Optional Closing Date will be subject to the accuracy of the representations and warranties on the part of the Company and the Selling Stockholders herein, to the accuracy of the statements of Company officers made pursuant to the provisions hereof, to the performance by the Company and the Selling Stockholders of their obligations hereunder and to the following additional conditions precedent:

     (a) The Representatives shall have received a letter, dated the date of delivery thereof (which, if the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement, shall be on or prior to the date of this Agreement or, if the Effective Time of the Initial Registration Statement is subsequent to the execution and delivery of this Agreement, shall be prior to the filing of the amendment or post-effective amendment to the registration statement to be filed shortly prior to such Effective Time), of

     (i) PricewaterhouseCoopers LLP confirming that they are independent public accountants within the meaning of the Securities Act and the applicable published Rules and Regulations thereunder and stating to the effect that:

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     (A) in their opinion the financial statements and schedules examined by them and included in the Registration Statements comply as to form in all material respects with the applicable accounting requirements of the Securities Act and the related Rules and Regulations;

     (B) they have performed the procedures specified by the American Institute of Certified Public Accountants for a review of interim financial information as described in Statement of Auditing Standards No. 100, Interim Financial Information, on the unaudited financial statements included in the Registration Statements;

     (C) on the basis of the review referred to in clause (B) above, a reading of the latest available interim financial statements of the Company, inquiries of officials of the Company who have responsibility for financial and accounting matters and other specified procedures, nothing came to their attention that caused them to believe that:

     (1) the unaudited financial statements included in the Registration Statements do not comply as to form in all material respects with the applicable accounting requirements of the Securities Act and the related published Rules and Regulations or any material modifications should be made to such unaudited financial statements for them to be in conformity with generally accepted accounting principles;

     (2) at the date of the latest available balance sheet read by such accountants, or at a subsequent specified date not more than three business days prior to the date of this Agreement, there was any change in the capital stock or any increase in short-term indebtedness or long-term debt of the Company and its consolidated subsidiaries or, at the date of the latest available balance sheet read by such accountants, there was any decrease in consolidated net current assets or stockholders’ equity, as compared with amounts shown on the latest balance sheet included in the Prospectus; or

     (3) for the period from the closing date of the latest income statement included in the Prospectus to the closing date of the latest available income statement read by such accountants, or from the date of the latest available income statement read by such accountants to a subsequent specified date not more than three business days prior to the date of this Agreement, there were any decreases, as compared with the corresponding period of the previous year, in consolidated net sales or in the total or per share amounts of income before extraordinary items or consolidated net income;

except in all cases set forth in clauses (2) and (3) above for changes, increases or decreases which the Prospectus discloses have occurred or which are described in such letter;

     (D) they have compared specified dollar amounts (or percentages derived from such dollar amounts) and other financial information contained in the Registration Statements (in each case to the extent that such dollar amounts, percentages and other financial information are derived from the general accounting records of the Company and its subsidiaries subject to the internal controls of the Company’s accounting system or are derived directly from such records by analysis or computation) with the results obtained from inquiries, a reading of such general accounting records and other procedures specified in such letter and have found such

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dollar amounts, percentages and other financial information to be in agreement with such results, except as otherwise specified in such letter;

     (E) they have read and compared the executive compensation information included in the Registration Statements with the requirements of item 402 of Regulation S-K and inquired of certain officials of the Company who have responsibility for financial and accounting matters whether such executive compensation information conforms in all material respects with the disclosure requirements of item 402 of Regulation S-K, and that nothing came to their attention that caused them to believe that such information did not conform in all material respects with the disclosure requirements of Regulation S-K; and

     (F) they have read and compared the financial information specified in such letter included in the Registration Statements under the heading “Selected Consolidated Financial Data” with the requirements of item 301 of Regulation S-K and inquired of certain officials of the Company who have responsibility for financial and accounting matters whether such financial information conforms in all material respects with the disclosure requirements of item 301 of Regulation S-K, and that nothing came to their attention that caused them to believe that such information did not conform in all material respects with the disclosure requirements of Regulation S-K;

     (ii) the Chief Financial Officer of the Company with respect to certain financial information in the Registration Statements in form and substance reasonably satisfactory to the Representatives.

For purposes of this subsection, (i) if the Effective Time of the Initial Registration Statements is subsequent to the execution and delivery of this Agreement, “Registration Statements” shall mean the initial registration statement as proposed to be amended by the amendment or post-effective amendment to be filed shortly prior to its Effective Time, (ii) if the Effective Time of the Initial Registration Statements is prior to the execution and delivery of this Agreement but the Effective Time of the Additional Registration Statement is subsequent to such execution and delivery, “Registration Statements” shall mean the Initial Registration Statement and the Additional Registration Statement as proposed to be filed or as proposed to be amended by the post-effective amendment to be filed shortly prior to its Effective Time, and (iii) “Prospectus” shall mean the prospectus included in the Registration Statements.

     (b) If the Effective Time of the Initial Registration Statement is not prior to the execution and delivery of this Agreement, such Effective Time shall have occurred not later than 10:00 P.M., New York time, on the date of this Agreement or such later date as shall have been consented to by the Representatives. If the Effective Time of the Additional Registration Statement (if any) is not prior to the execution and delivery of this Agreement, such Effective Time shall have occurred not later than 10:00 P.M., New York time, on the date of this Agreement or, if earlier, the time the Prospectus is printed and distributed to any Underwriter, or shall have occurred at such later date as shall have been consented to by the Representatives. If the Effective Time of the Initial Registration Statement is prior to the execution and delivery of this Agreement, the Prospectus shall have been filed with the Commission in accordance with the Rules and Regulations and Section 5(a) of this Agreement. Prior to such Closing Date, no stop order suspending the effectiveness of a Registration Statement shall have been issued and no proceedings for that purpose shall have been instituted or, to the knowledge of any Selling Stockholder, the Company or the Representatives, shall be contemplated by the Commission.

     (c) Subsequent to the execution and delivery of this Agreement, there shall not have occurred (i) any change, or any development or event involving a prospective change, in the condition

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(financial or other), business, properties or results of operations of the Company and its subsidiaries taken as one enterprise which, in the judgment of a majority in interest of the Underwriters including the Representatives, is material and adverse and makes it impractical or inadvisable to proceed with completion of the public offering or the sale of and payment for the Offered Securities; (ii) any downgrading in the rating of any debt securities of the Company by any “nationally recognized statistical rating organization” (as defined for purposes of Rule 436(g) under the Securities Act), or any public announcement that any such organization has under surveillance or review its rating of any debt securities of the Company (other than an announcement with positive implications of a possible upgrading, and no implication of a possible downgrading, of such rating); (iii) any change in U.S. or international financial, political or economic conditions or currency exchange rates or exchange controls as would, in the judgment of a majority in interest of the Underwriters including the Representatives, be likely to prejudice materially the success of the proposed issue, sale or distribution of the Offered Securities, whether in the primary market or in respect of dealings in the secondary market; (iv) any material suspension or material limitation of trading in securities generally on The New York Stock Exchange or any setting of minimum prices for trading on such exchange; (v) any suspension of trading of any securities of the Company on any exchange or in the over-the-counter market; (vi) any banking moratorium declared by U.S. Federal or New York authorities; (vii) any major disruption of settlements of securities or clearance services in the United States or (viii) any attack on, outbreak or escalation of hostilities or act of terrorism involving the United States, any declaration of war by Congress or any other national or international calamity or emergency if, in the judgment of a majority in interest of the Underwriters including the Representatives, the effect of any such attack, outbreak, escalation, act, declaration, calamity or emergency makes it impractical or inadvisable to proceed with completion of the public offering or the sale of and payment for the Offered Securities.

     (d) The Representatives shall have received an opinion and letter, each dated such Closing Date, of Latham & Watkins LLP, counsel for the Company, substantially in the form of Exhibit A hereto and in substance reasonably satisfactory to the Representatives.

     (e) The Representatives shall have received an opinion, dated such Closing Date, of Spiro Fotopoulos, Director of Legal Affairs for the Company, substantially to the effect that:

     (i) There are no contracts, agreements or understandings known to such counsel between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to the Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Securities Act that have not been satisfied or waived prior to the date hereof or are inapplicable to the sale of securities in a public offering; and

     (ii) Except as disclosed in the Prospectus, there are no pending actions, suits or proceedings against or affecting the Company, any of its subsidiaries or any of their respective properties that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a Material Adverse Effect, or would materially and adversely affect the ability of the Company to perform its obligations under this Agreement, or which are otherwise material in the context of the sale of the Offered Securities; and, to the knowledge of such counsel, no such actions, suits or proceedings are threatened or contemplated.

     (f) For each Selling Stockholder that is not a natural person, the Representatives shall have received an opinion, dated such Closing Date, of counsel for each such Selling Stockholder, substantially to the effect that:

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     (i) Each such Selling Stockholder had valid and unencumbered title to the Offered Securities delivered by such Selling Stockholder on such Closing Date and had full right, power and authority to enter into this Agreement and to sell, assign, transfer and deliver the Offered Securities delivered by such Selling Stockholder on such Closing Date hereunder; and the several Underwriters have acquired valid and unencumbered title to the Offered Securities purchased by them from such Selling Stockholder on such Closing Date hereunder;

     (ii) No consent, approval, authorization or order of, or filing with, any governmental agency or body or any court is required to be obtained or made by any such Selling Stockholder for the consummation of the transactions contemplated by the Custody Agreement or this Agreement in connection with the sale of the Offered Securities sold by such Selling Stockholder, except such as have been obtained and made under the Securities Act and such as may be required under state securities laws;

     (iii) The execution, delivery and performance of the Custody Agreement and this Agreement and the consummation of the transactions therein and herein contemplated will not result in a breach or violation of any of the terms and provisions of, or constitute a default under, any statute, any rule, regulation or order of any governmental agency or body or any court having jurisdiction over any such Selling Stockholder or any of its properties or any agreement or instrument to which any such Selling Stockholder is a party or by which any such Selling Stockholder is bound or to which any of the properties of any such Selling Stockholder is subject, or the charter or by-laws of any such Selling Stockholder which is a corporation;

     (iv) The Power of Attorney and related Custody Agreement with respect to each such Selling Stockholder has been duly authorized, executed and delivered by such Selling Stockholder and constitute valid and legally binding obligations of each such Selling Stockholder enforceable in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and to general equity principles; and

     (v) This Agreement has been duly authorized, executed and delivered by each such Selling Stockholder.

     (g) For each Selling Stockholder that is a natural person, the Representatives shall have received an opinion, dated such Closing Date, of Spiro Fotopoulos, Director of Legal Affairs for the Company, for each such Selling Stockholder, substantially to the effect that each such Selling Stockholder had valid and unencumbered title to the Offered Securities delivered by such Selling Stockholder on such Closing Date and had full right, power and authority to enter into this Agreement and to sell, assign, transfer and deliver the Offered Securities delivered by such Selling Stockholder on such Closing Date hereunder; and the several Underwriters have acquired valid and unencumbered title to the Offered Securities purchased by them from such Selling Stockholders on such Closing Date hereunder;

     (h) The Representatives shall have received from Cravath, Swaine & Moore LLP, counsel for the Underwriters, such opinion or opinions, dated such Closing Date, with respect to the incorporation of the Company, the validity of the Offered Securities delivered on such Closing Date, the Registration Statements, the Prospectus and other related matters as the Representatives may require, and the Selling Stockholders and the Company shall have furnished to such counsel such documents as they request for the purpose of enabling them to pass upon such matters.

     (i) The Representatives shall have received a certificate, dated such Closing Date, of the President or any Vice President and a principal financial or accounting officer of the Company in which such officers, to the best of their knowledge after reasonable investigation, shall state on behalf of the Company that: the representations and warranties of the Company in this Agreement

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are true and correct; the Company has complied in all material respects with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date; no stop order suspending the effectiveness of any Registration Statement has been issued and, to such officer’s knowledge, no proceedings for that purpose have been instituted or are contemplated by the Commission; the Additional Registration Statement (if any) satisfying the requirements of subparagraphs (1) and (3) of Rule 462(b) was filed pursuant to Rule 462(b), including payment of the applicable filing fee in accordance with Rule 111(a) or (b) under the Securities Act, prior to the time the Prospectus was printed and distributed to any Underwriter; and, subsequent to the date of the most recent financial statements in the Prospectus, there has been no material adverse change, nor any development or event involving a prospective material adverse change, in the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole except as set forth in the Prospectus or as described in such certificate.

     (j) The Representatives shall have received a letter, dated such Closing Date, of PricewaterhouseCoopers LLP which meets the requirements of subsection (a)(i) of this Section, except that the specified date referred to in such subsection will be a date not more than three days prior to such Closing Date for the purposes of this subsection.

     (k) On or prior to the date of this Agreement, the Representatives shall have received lockup letters from each of the executive officers and directors of the Company.

     (l) The Custodian will deliver to the Representatives a letter stating that they will deliver to each Selling Stockholder a United States Treasury Department Form 1099 (or other applicable form or statement specified by the United States Treasury Department regulations in lieu thereof) on or before January 31 of the year following the date of this Agreement.

The Selling Stockholders and the Company will furnish the Representatives with such conformed copies of such opinions, certificates, letters and documents as the Representatives reasonably request. The Representatives may in their sole discretion waive on behalf of the Underwriters compliance with any conditions to the obligations of the Underwriters hereunder.

     7. Indemnification and Contribution. (a) The Company will indemnify and hold harmless each Underwriter, its partners, affiliates, members, directors and officers and each person, if any who controls such Underwriter within the meaning of Section 15 of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which such Underwriter may become subject, under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in any Registration Statement, the Prospectus, or any amendment or supplement thereto, or any related preliminary prospectus, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that the Company will not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement in or omission or alleged omission from any of such documents in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in subsection (c) below; and provided further, that the Company shall not be liable to any Underwriter under the indemnity agreement in this subsection (a) with respect to any preliminary prospectus to the extent that any such loss, claim, damage or liability of such Underwriter results from the fact that such Underwriter sold Offered Securities to a person to whom it shall be established that there was not sent or given, at or prior to the written confirmation of such sale, a copy of the Prospectus or of the Prospectus as then amended or supplemented in any case where such delivery is required by the Securities Act if the Company has previously furnished

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copies thereof in sufficient quantity to such Underwriter and sufficiently in advance of the Closing Date to allow for distribution by such Closing Date and the loss, claim, damage or liability of such Underwriter results from an untrue statement or omission of a material fact contained in or omitted from the preliminary prospectus which was identified in writing at such time to such Underwriter and corrected in the Prospectus or in the Prospectus as then amended or supplemented and such correction would have cured the defect giving rise to such loss, claim, damage or liability.

     (b) The Selling Stockholders, severally and not jointly, will indemnify and hold harmless each Underwriter, its partners, affiliates, members, directors and officers and each person who controls such Underwriter within the meaning of Section 15 of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which such Underwriter may become subject, under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in any Registration Statement, the Prospectus, or any amendment or supplement thereto, or any related preliminary prospectus, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter in connection with investigating or defending any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that a Selling Stockholder will not be liable in any such case except to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement in or omission or alleged omission from any of such documents in reliance upon and in conformity with written information furnished to the Company by or on behalf of such Selling Stockholder specifically for use therein; provided further, however, that (i) in no such case shall such Selling Stockholder be liable or responsible for any amount in excess of the proceeds (net of underwriting discounts and commissions but before deducting other expenses) applicable to the Offered Securities sold by such Selling Stockholder pursuant to the transactions contemplated hereby; and (ii) Selling Stockholders shall not be liable to any Underwriter under the indemnity agreement in this subsection (b) with respect to any preliminary prospectus to the extent that any such loss, claim, damage or liability of such Underwriter results from the fact that such Underwriter sold Offered Securities to a person as to whom it shall be established that there was not sent or given, at or prior to the written confirmation of such sale, a copy of the Prospectus or of the Prospectus as then amended or supplemented in any case where such delivery is required by the Securities Act if the Company has previously furnished copies thereof in sufficient quantity to such Underwriter and sufficiently in advance of the Closing Date to allow for distribution by such Closing Date and the loss, claim, damage or liability of such Underwriter results from an untrue statement or omission of a material fact contained in or omitted from the preliminary prospectus which was identified in writing at such time to such Underwriter and corrected in the Prospectus or in the Prospectus as then amended or supplemented and such correction would have cured the defect giving rise to such loss, claim, damage or liability.

     (c) Each Underwriter will severally and not jointly indemnify and hold harmless the Company, its directors and officers and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act, and each Selling Stockholder against any losses, claims, damages or liabilities to which the Company or such Selling Stockholder may become subject, under the Securities Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in any Registration Statement, the Prospectus, or any amendment or supplement thereto, or any related preliminary prospectus, or arise out of or are based upon the omission or the alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives specifically for use therein, and will reimburse any legal or other expenses reasonably incurred by the Company and each Selling Stockholder in connection with investigating or defending any such loss, claim, damage, liability or action as such expenses are incurred, it being understood and agreed that the only such information furnished by any Underwriter consists of the following information in the Prospectus furnished on behalf of each Underwriter: the concession and

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reallowance figures appearing in the fourth paragraph under the caption “Underwriting” and the information contained in the sixth, fifteenth and nineteenth paragraphs (respectively regarding sales to discretionary accounts, stabilization and electronic distribution) under the caption “Underwriting”.

     (d) Promptly after receipt by an indemnified party under this Section of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against an indemnifying party under subsection (a), (b) or (c) above, notify the indemnifying party of the commencement thereof; but the failure to notify the indemnifying party shall not relieve it from any liability that it may have under subsection (a), (b) or (c) above except to the extent that it has been materially prejudiced (through the forfeiture of substantive rights or defenses) by such failure; and provided further that the failure to notify the indemnifying party shall not relieve it from any liability that it may have to an indemnified party otherwise than under subsection (a), (b) or (c) above. In case any such action is brought against any indemnified party and it notifies an indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein and, to the extent that it may wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party will not be liable to such indemnified party under this Section for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof other than reasonable costs of investigation. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened action in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party unless such (i) settlement includes an unconditional release of such indemnified party from all liability on any claims that are the subject matter of such action and (ii) does not include a statement as to, or an admission of, fault, culpability or a failure to act by or on behalf of an indemnified party.

     (e) If the indemnification provided for in this Section is unavailable or insufficient to hold harmless an indemnified party under subsection (a), (b) or (c) above, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of the losses, claims, damages or liabilities referred to in subsection (a), (b) or (c) above (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Selling Stockholders on the one hand and the Underwriters on the other from the offering of the Securities or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company and the Selling Stockholders on the one hand and the Underwriters on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities as well as any other relevant equitable considerations. The relative benefits received by the Company and the Selling Stockholders on the one hand and the Underwriters on the other shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Selling Stockholders bear to the total underwriting discounts and commissions received by the Underwriters. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company, the Selling Stockholders or the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such untrue statement or omission. The amount paid by an indemnified party as a result of the losses, claims, damages or liabilities referred to in the first sentence of this subsection (e) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any action or claim which is the subject of this subsection (e). Notwithstanding the provisions of this subsection (e), no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission and no Selling Stockholder shall be required to contribute any amount that, when added to any liability of such Selling Stockholder under subsection (b) above, exceeds the proceeds (net of underwriting discounts and commissions but before deducting other expenses)

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applicable to the Offered Securities sold by such Selling Stockholder pursuant to the transactions contemplated hereby. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations in this subsection (e) to contribute are several in proportion to their respective underwriting obligations and not joint.

     (f) The obligations of the Company and the Selling Stockholders under this Section shall be in addition to any liability which the Company and the Selling Stockholders may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Securities Act; and the obligations of the Underwriters under this Section shall be in addition to any liability which the respective Underwriters may otherwise have and shall extend, upon the same terms and conditions, to each director of the Company, to each officer of the Company who has signed a Registration Statement and to each person, if any, who controls the Company within the meaning of the Securities Act.

     8. Default of Underwriters. If any Underwriter or Underwriters default in their obligations to purchase Offered Securities hereunder on either the First or any Optional Closing Date and the aggregate number of shares of Offered Securities that such defaulting Underwriter or Underwriters agreed but failed to purchase does not exceed 10% of the total number of shares of Offered Securities that the Underwriters are obligated to purchase on such Closing Date, the Representatives may make arrangements satisfactory to the Selling Stockholders for the purchase of such Offered Securities by other persons, including any of the Underwriters, but if no such arrangements are made by such Closing Date, the non-defaulting Underwriters shall be obligated severally, in proportion to their respective commitments hereunder, to purchase the Offered Securities that such defaulting Underwriters agreed but failed to purchase on such Closing Date. If any Underwriter or Underwriters so default and the aggregate number of shares of Offered Securities with respect to which such default or defaults occur exceeds 10% of the total number of shares of Offered Securities that the Underwriters are obligated to purchase on such Closing Date and arrangements satisfactory to the Representatives and the Selling Stockholders for the purchase of such Offered Securities by other persons are not made within 36 hours after such default, this Agreement will terminate without liability on the part of any non-defaulting Underwriter, the Company or the Selling Stockholders, except as provided in Section 9 (provided that if such default occurs with respect to Optional Securities after the First Closing Date, this Agreement will not terminate as to the Firm Securities or any Optional Securities purchased prior to such termination). As used in this Agreement, the term “Underwriter” includes any person substituted for an Underwriter under this Section. Nothing herein will relieve a defaulting Underwriter from liability for its default.

     9. Survival of Certain Representations and Obligations. The respective indemnities, agreements, representations, warranties and other statements of the Selling Stockholders, of the Company or its officers and of the several Underwriters set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation, or statement as to the results thereof, made by or on behalf of any Underwriter, any Selling Stockholder, the Company or any of their respective representatives, officers or directors or any controlling person, and will survive delivery of and payment for the Offered Securities. If this Agreement is terminated pursuant to Section 8 or if for any reason the purchase of the Offered Securities by the Underwriters is not consummated, the Selling Stockholders shall remain responsible for the expenses to be paid or reimbursed by them pursuant to Section 5 and the respective obligations of the Company, the Selling Stockholders, and the Underwriters pursuant to Section 7 shall remain in effect, and if any Offered Securities have been purchased hereunder the representations and warranties in Section 2 and all obligations under Section 5 shall also remain in effect. If the purchase of the Offered Securities by the Underwriters is not consummated for any reason other than solely because of the termination of this Agreement pursuant to Section 8 or pursuant to the occurrence of any event specified in clause (iii), (iv), (vi), (vii) or (viii) of Section 6(c), the Selling Stockholders will, jointly and severally, reimburse the Underwriters for all out-of-pocket expenses (including fees and disbursements of counsel) reasonably incurred by them in connection with the offering of the Offered Securities.

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     10. Notices. All communications hereunder will be in writing and, if sent to the Underwriters, will be mailed, delivered or faxed and confirmed to the Representatives c/o Credit Suisse First Boston LLC, Eleven Madison Avenue, New York, NY 10010-3629, Attention: Transactions Advisory Group, or, if sent to the Company or any Selling Stockholder, will be mailed, delivered or faxed and confirmed to it at 12120 Sunset Hills Road, Suite 600, Reston, VA 20190, Attention: Patrick K. Donnelly; provided, however, that any notice to an Underwriter pursuant to Section 7 will be mailed, delivered or faxed and confirmed to such Underwriter.

     11. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto and their respective personal representatives and successors and the officers and directors and controlling persons referred to in Section 7, and no other person will have any right or obligation hereunder.

     12. Representation. The Representatives will act for the several Underwriters in connection with the transactions contemplated by this Agreement, and any action under this Agreement taken by the Representatives jointly will be binding upon all the Underwriters. The Attorneys will act for the Selling Stockholders in connection with such transactions, and any action under or in respect of this Agreement taken by the Attorneys (or any of them) will be binding upon all the Selling Stockholders.

     13. Counterparts. This Agreement may be executed in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same Agreement.

     14. Applicable Law. This Agreement shall be governed by, and construed in accordance with, the laws of the State of New York.

     The Company hereby submits to the non-exclusive jurisdiction of the Federal and state courts in the Borough of Manhattan in The City of New York in any suit or proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

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     If the foregoing is in accordance with the Representatives’ understanding of our agreement, kindly sign and return to the Company one of the counterparts hereof, whereupon it will become a binding agreement among the Selling Stockholders, the Company and the several Underwriters in accordance with its terms.

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