3,000,000

Exhibit 1.1

EXECUTION COPY

3,000,000

Parallel Petroleum Corporation

Common Stock

UNDERWRITING AGREEMENT

December 3, 2007

JEFFERIES & COMPANY, INC.
520 Madison Avenue
New York, New York 10022

Ladies and Gentlemen:

     Introductory. Parallel Petroleum Corporation, a Delaware corporation (the “Company”), proposes to issue and sell to Jefferies & Company, Inc., as sole underwriter (the “Underwriter”), an aggregate of 3,000,000 shares of its common stock, par value $.01 per share (the “Shares”). The 3,000,000 Shares to be sold by the Company are collectively called the “Offered Shares.”

     The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a shelf registration statement on Form S-3 (File No. 333-146775), which contains a form of base prospectus (the “Base Prospectus”) to be used in connection with the public offering and sale of the Offered Shares. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, in the form in which it was declared effective by the Commission under the Securities Act of 1933, as amended (the “Securities Act”), and the rules and regulations promulgated thereunder (the “Securities Act Regulations”), including all documents incorporated or deemed to be incorporated by reference therein and any information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430B under the Securities Act or the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “Exchange Act”), is called the “Registration Statement.” The preliminary prospectus supplement dated December 3, 2007, describing the Offered Shares and the offering thereof, together with the Base Prospectus, is called the “Preliminary Prospectus,” and the Preliminary Prospectus and any other preliminary prospectus supplement to the Base Prospectus that describes the Offered Shares and the offering thereof and is used prior to the filing of the Prospectus (as defined below), together with the Base Prospectus, is called a “preliminary prospectus.” As used herein, the term “Prospectus” shall mean the final prospectus supplement to the Base Prospectus that describes the Offered Shares and the offering thereof (the “Final Prospectus Supplement”), together with the Base Prospectus, in the form first used by the Underwriter to confirm sales of the Offered Shares or in the form first made available to the Underwriter by the Company to meet requests of purchasers pursuant to Rule 173 under the Securities Act. As used herein, “Applicable Time” is 5:00 p.m. (New York time) on December 3, 2007. As used herein, “free writing prospectus” has the meaning set forth in Rule 405 under the Securities Act, and “Time of Sale Prospectus” means the Preliminary Prospectus together with the information identified in Schedule A hereto, and each “road show” (as defined in Rule 433 under the Securities Act), if any, related to the offering of the Offered Shares contemplated hereby that is a “written communication” (as defined in Rule 405 under the Securities Act) (each such road show, a “Road Show”). As used herein, the terms

“Registration Statement”, “Preliminary Prospectus”, “Time of Sale Prospectus” and “Prospectus” shall include the documents incorporated and deemed to be incorporated by reference therein. All references in this Agreement to amendments or supplements to the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Time of Sale Prospectus or the Prospectus shall be deemed to mean and include the filing of any document under the Exchange Act which is or is deemed to be incorporated by reference in the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus, as the case may be. All references in this Agreement to (i) the Registration Statement, any Preliminary Prospectus, a preliminary prospectus or the Prospectus, or any amendments or supplements to any of the foregoing, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“EDGAR”) and (ii) the Prospectus shall be deemed to include the “electronic Prospectus” provided for use in connection with the offering of the Offered Shares as contemplated by Section 3(n) of this Agreement.

     All references in this Agreement to financial statements and schedules and other information which are “contained,” “included” or “stated” in the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus (and all other references of like import) shall be deemed to mean and include all such financial statements and schedules and other information which is or is deemed to be incorporated by reference in the Registration Statement or the Prospectus, as the case may be; and all references in this Agreement to amendments or supplements to the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus, as the case may be, and all references in this Agreement to amendments or supplements to the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus shall be deemed to mean and include the filing of any document under the Exchange Act which is or is deemed to be incorporated by reference in the Registration Statement, the Preliminary Prospectus, any preliminary prospectus, the Base Prospectus, the Time of Sale Prospectus or the Prospectus, as the case may be.

     The Company hereby confirms its agreements with the Underwriter as follows:

     Section 1. Representations and Warranties of the Company.

     The Company hereby represents, warrants and covenants to the Underwriter, as of the date of this Agreement and as of the Closing Date (as hereinafter defined) and covenants with the Underwriter, as follows:

     (a) Compliance with Registration Requirements. The Registration Statement has been declared effective by the Commission under the Securities Act. The Company has complied to the Commission’s satisfaction with all requests of the Commission for additional or supplemental information, if applicable. No stop order suspending the effectiveness of the Registration Statement is in effect and no proceedings for such purpose have been instituted or are pending or, to the best knowledge of the Company, are contemplated or threatened by the Commission.

     Each preliminary prospectus and the Prospectus when filed complied in all material respects with the Securities Act and, if filed by electronic transmission pursuant to EDGAR (except as may be permitted by Regulation S-T under the Securities Act), was identical to the copy thereof delivered to the Underwriter for use in connection with the offer and sale of the Offered Shares. Each of the Registration Statement and any post-effective amendment thereto, at the time it became effective and at all subsequent times, complied and will comply in all material respects with the Securities Act and did not and will not contain any untrue statement of a

material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading. As of the Applicable Time, the Time of Sale Prospectus did not, and at the time of each sale of the Offered Shares and at the Closing Date (as defined in Section 2), the Time of Sale Prospectus, as then amended or supplemented by the Company, if applicable, will not, contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. The Prospectus, as amended or supplemented, as of its date and at all subsequent times, did not and will not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties set forth in the three immediately preceding sentences do not apply to statements in or omissions from the Registration Statement, or any post-effective amendment thereto, or the Prospectus or the Time of Sale Prospectus, or any amendments or supplements thereto, made in reliance upon and in conformity with information relating to any Underwriter furnished to the Company in writing by the Underwriter expressly for use therein, it being understood and agreed that the only such information furnished by the Underwriter to the Company consists of the information described in Section 9(b) below. There are no contracts or other documents required to be described in the Time of Sale Prospectus or the Prospectus or to be filed as exhibits to the Registration Statement which have not been described or filed as required.

     The Company is not an “ineligible issuer” in connection with the offering of the Offered Shares pursuant to Rules 164, 405 and 433 under the Securities Act. Any free writing prospectus that the Company is required to file pursuant to Rule 433(d) under the Securities Act has been, or will be, filed with the Commission in accordance with the requirements of the Securities Act. Each free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) under the Securities Act or that was prepared by or on behalf of or used or referred to by the Company complies or will comply in all material respects with the requirements of Rule 433 under the Securities Act including timely filing with the Commission or retention where required and legending, and each such free writing prospectus, as of its issue date and at all subsequent times through the completion of the public offer and sale of the Offered Shares did not, does not and will not include any information that conflicted, conflicts with or will conflict with the information contained in the Registration Statement or the Prospectus, including any document incorporated by reference therein. Except for the free writing prospectuses, if any, identified in Schedule B hereto, and electronic road shows, if any, furnished to you before first use, the Company has not prepared, used or referred to, and will not, without your prior consent, prepare, use or refer to, any free writing prospectus.

     (b) Offering Materials Furnished to Underwriter. The Company has delivered to the Underwriter a complete copy of the Registration Statement, each amendment thereto and of each consent and certificate of experts filed as a part thereof, and conformed copies of the Registration Statement, each amendment thereto and preliminary prospectuses, the Time of Sale Prospectus, the Prospectus, as amended or supplemented, and any free writing prospectus reviewed and consented to by the Underwriter, in such quantities and at such places as the Underwriter has reasonably requested.

     (c) Distribution of Offering Materials By the Company. The Company has not distributed and will not distribute, prior to the later of the completion of the Underwriter’s distribution of the Offered Shares, any offering material in connection with the offering and sale of the Offered Shares other than a preliminary prospectus, the Time of Sale Prospectus, the Prospectus, any free writing prospectus reviewed and consented to by the Underwriter, or the Registration Statement.

     (d) The Underwriting Agreement. This Agreement has been duly authorized, executed and delivered by, and is a valid and binding agreement of, the Company, enforceable in accordance with its terms, except as rights to indemnification hereunder may be limited by applicable law and except as the enforcement hereof may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws relating to or affecting the rights and remedies of creditors or by general equitable principles.

     (e) Authorization of the Offered Shares. The Offered Shares have been duly authorized for issuance and sale pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued, fully paid and nonassessable, and the issuance and sale of the Offered Shares is not subject to any preemptive rights, rights of first refusal or other similar rights to subscribe for or purchase the Offered Shares. The statements set forth in the Prospectus under the caption “Description of Capital Stock—Common Stock,” insofar as it purports to constitute a summary of the terms of the Common Stock, are accurate and complete in all respects; and no holder of the Shares will be subject to personal liability under the Delaware General Corporation Law by reason of being such a holder.

     (f) Incorporated Documents. Each document incorporated or deemed to be incorporated by reference in the Registration Statement and the Prospectus, at the time they were or hereafter are filed with the Commission, complied and will comply when filed with the requirements of the Exchange Act and the rules and regulations of the Commission thereunder (the “Exchange Act Regulations”), and, when read together with the other information in the Prospectus, at the date of the Prospectus, and at the Closing Date, did not and will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Registration Statement or Prospectus, when such documents become effective or are filed with the Commission, as the case may be, will conform to the requirements of the Securities Act or the Exchange Act, as applicable, and will not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading.

     (g) Independent Registered Public Accounting Firm – BDO Seidman, LLP. The accountants, BDO Seidman, LLP, who have certified certain audited financial statements (which term as used in this Agreement includes the related notes thereto) contained or incorporated by reference in the Registration Statement and included in the Prospectus and the Time of Sale Prospectus (or any amendment or supplement thereto), are (A) an independent registered public accounting firm with respect to the Company, as required by the Securities Act and the Securities Act Regulations and the Exchange Act and the Exchange Act Regulations, (B) in compliance with the applicable requirements relating to qualification of accountants under Rule 2-01 of Regulation S-X and (C) a registered public accounting firm as defined by the Public Company Accounting Oversight Board (the “PCAOB”) whose registration has not been suspended or revoked and who has not requested such registration to be withdrawn.

     (h) Financial Statements. The historical consolidated financial statements of the Company, including any amendments, filed as part of the Registration Statement or included or incorporated by reference in the Prospectus, together with the related schedules and notes thereto, present fairly the financial condition of the Company and its consolidated subsidiaries at the dates indicated and the statements of operations and cash flows of the Company and its consolidated subsidiaries for the periods specified. Such financial statements, including any amendments, have been prepared in conformity with accounting principles generally accepted in the United

States of America (“GAAP”) applied, except as disclosed therein, on a consistent basis throughout the periods involved, and the requirements of Regulation S-X promulgated under the Securities Act. The supporting schedules, if any, included in the Registration Statement and the Prospectus present fairly in accordance with GAAP the information required to be stated therein.

All financial statements, including any amendments, required to be included in the Prospectus, or incorporated by reference in the Registration Statement, under Item 11 of Form S-3 have been so included or incorporated, and to the extent such financial statements are required by Rule 3-05 of Regulation S-X present fairly the financial information contained therein as of the dates and periods specified in conformity with GAAP, and to the extent such financial statements constitute pro forma financial statements such financial statements present fairly the information contained therein, have been prepared in accordance with the Commission’s rules and guidelines with respect to pro forma financial statements and have been properly presented on the bases described therein, and the assumptions used in the preparation thereof are reasonable and the adjustments used therein are appropriate to give effect to the transactions and circumstances referred to therein. No other financial statements or supporting schedules are required to be included in the Registration Statement or any applicable Prospectus. To the Company’s knowledge, no person who has been suspended or barred from being associated with a registered public accounting firm, or who has failed to comply with any sanction pursuant to Rule 5300 promulgated by the PCAOB, has participated in or otherwise aided the preparation of, or audited, the financial statements, supporting schedules or other financial data filed with the Commission as a part of the Registration Statement and included in any Applicable Prospectus

     (i) No Material Adverse Change in Business. Except as otherwise disclosed in the Time of Sale Prospectus, subsequent to the respective dates as of which information is given in the Time of Sale Prospectus: (A) there has been no material adverse change, or any development that could reasonably be expected to result in a material adverse change, in the condition, financial or otherwise, or in the earnings, business affairs or business prospects, whether or not arising in the ordinary course of business, of the Company (a “Material Adverse Change”); (B) the Company has not incurred any material liability or obligation, indirect, direct or contingent, not in the ordinary course of business, nor entered into any material transaction or agreement not in the ordinary course of business; (C) there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of capital stock; and (D) there has not been any material adverse change in the capital stock, short-term debt or long-term debt of the Company.

     (j) Good Standing of the Company. The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Delaware and has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Registration Statement and the Prospectus and to enter into and perform its obligations under this Agreement. The Company is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure to be so qualified or in good standing would not have a Material Adverse Change. To the Company’s knowledge, no proceeding has been instituted in any jurisdiction revoking, limiting or curtailing or seeking to revoke, limit or curtail, such power and authority or qualification. The Company does not own, lease or license any asset or property outside of the United States of America.

     (k) No Subsidiaries. The Company currently has no subsidiaries that are or would be consolidated with the Company for accounting purposes.

     (l) Capitalization. The authorized, issued and outstanding shares of capital stock of the Company are as set forth in the Prospectus. All of the shares of issued and outstanding capital stock of the Company have been duly authorized and validly issued, were issued in compliance with federal and state securities laws, are fully paid and nonassessable and conform to the description thereof contained in the Registration Statement and the Prospectus. All of the Company’s options, warrants and other rights to purchase or exchange any securities for shares of the Company’s capital stock have been duly and validly authorized and issued, were issued in compliance with federal and state securities laws, and conform to the description thereof contained in the Registration Statement and the Prospectus. None of the outstanding shares of capital stock of the Company were issued in violation of preemptive or other similar rights of any securityholder of the Company.

     (m) Authorization and Description of Shares. The Offered Shares have been duly authorized for issuance and sale to the Underwriter pursuant to this Agreement and, when issued and delivered by the Company pursuant to this Agreement against payment of the consideration set forth herein, will be validly issued, fully paid and nonassessable. The Shares (including the Offered Shares) conform in all material respects to the description thereof contained in the Time of Sale Prospectus.

     (n) Absence of Defaults and Conflicts. The Company is not in violation of its charter or bylaws or in default in the performance or observance of any material obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or other agreement or instrument to which the Company is a party or by which it may be bound, or to which any of the property or assets of the Company is subject (collectively including without limitation the (i) Third Amended and Restated Credit Agreement, dated as of December 23, 2005, as amended by First Amendment, dated as of August 18, 2006, Second Amendment, dated as of July 10, 2007, Third Amendment, dated as of July 31, 2007 and Fourth Amendment, dated as of November 30, 2007, by and among the Company, Citibank, N.A., and the other financial institutions parties thereto, and (ii) the Indenture, dated as of July 31, 2007, between the Company and Wells Fargo Bank, National Association (the “Credit Agreements”) and any “Credit Facilities” and “Loan Documents” as such terms are defined under each of the Credit Agreements, “Agreements and Instruments”). The execution, delivery and performance by the Company of its obligations under this Agreement and the consummation of the transactions contemplated herein and in the Registration Statement and the Prospectus (including the issuance and sale of the Offered Shares and the use of the proceeds from the sale of the Offered Shares as described in the Prospectus in the “Use of Proceeds” section of the Prospectus) and compliance by the Company with its obligations hereunder have been duly authorized by all necessary corporate action and do not and will not, whether with or without the giving of notice or passage of time or both, conflict with or constitute a breach of, or default or Repayment Event (as defined below) under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to, the Agreements and Instruments, nor will such action result in any violation of (A) the provisions of the charter or bylaws of the Company or (B) any applicable law, statute, rule, regulation, judgment, order, writ or decree of any government, government instrumentality or court, domestic or foreign, having jurisdiction over the Company or any of its assets, properties or operations, which violations, in the case of clause (B), would, individually or in the aggregate, have a Material Adverse Change. As used herein, a “Repayment Event” means any event or condition that gives the holder of any note, debenture or other evidence of indebtedness (or any person acting on such holder’s behalf) the right to require the repurchase, redemption or repayment of all or a portion of such indebtedness by the Company. Except for permits, consents, approvals and similar authorizations required under the securities or “Blue Sky” laws of certain jurisdictions, and except for such

permits, consents, approvals and authorizations which have been obtained, no permit, consent, approval, authorization or order of any court, governmental agency or body or financial institution is required in connection with the consummation of the transactions contemplated by this Agreement.

     (o) Absence of Labor Dispute. No labor dispute with the employees of the Company exists or, to the knowledge of the Company, is imminent that could reasonably be expected to result in a Material Adverse Change.

     (p) Absence of Proceedings. There is no action, suit, proceeding, inquiry or investigation before or brought by any court or governmental agency or body, domestic or foreign now pending, or, to the best of the Company’s knowledge, threatened against or directly affecting the Company which could reasonably be expected to result in a Material Adverse Change, or that might reasonably be expected to materially and adversely affect the consummation of the transactions contemplated in this Agreement or the performance by the Company of its obligations hereunder; and to the best of the Company’s knowledge, no such proceedings are threatened or contemplated by governmental authorities or threatened by others. The aggregate of all pending legal or governmental proceedings to which the Company is a party or of which any of its properties or assets is the subject that are not described in the Registration Statement and the Prospectus, including ordinary routine litigation incidental to the business, could not reasonably be expected to result in a Material Adverse Change.

     (q) Accuracy of Exhibits. There are no contracts or documents that are required to be described in the Registration Statement, the Prospectus or the documents incorporated by reference therein or to be filed as exhibits thereto that have not been so described and filed as required.

     (r) Absence of Further Requirements. No filing with, or authorization, approval, consent, license, order, registration, qualification or decree of, any court or governmental authority or agency is necessary or required for the performance by the Company of its obligations hereunder, in connection with the offering, issuance or sale of the Offered Shares hereunder or the consummation of the transactions contemplated by this Agreement, except (A) for such required under the Securities Act, the Securities Act Regulations, the Exchange Act, the Exchange Act Regulations and state securities or “Blue Sky” laws, (B) for such which have been, or prior to the applicable Date of Delivery (as defined below) will be, obtained or (C) for such which, if not obtained, would not, individually or in the aggregate, have a Material Adverse Change.

     (s) Possession of Intellectual Property. The Company owns or possesses or is licensed under, and has the right to use adequate rights, adequate know-how (including unpatented and/or unpatentable proprietary or confidential information, systems or procedures) or other intellectual property (collectively, “Intellectual Property”) necessary to carry on the business now operated by it, and has not received any notice of and, to the Company’s knowledge no claims have been made concerning, any infringement of or conflict with asserted rights of others with respect to any Intellectual Property or of any facts or circumstances that could reasonably be expected to render any Intellectual Property invalid or inadequate to protect the interests of the Company therein except for such conflicts and claims as could not, individually or in the aggregate, reasonably be expected to have a Material Adverse Change.

     (t) Possession of Licenses and Permits. The Company possesses all such permits, licenses, approvals, consents and other authorizations (collectively, “Governmental Licenses”)

issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the business in the manner described in the Prospectus, subject to such qualifications as may be set forth in the Prospectus and except for such permits which, if not obtained, would not, individually or in the aggregate, have a Material Adverse Change; the Company is in compliance with the terms and conditions of all such Governmental Licenses, subject to such qualifications as may be set forth in the Prospectus and except for such noncompliance which would not, individually or in the aggregate, have a Material Adverse Change; all of the Governmental Licenses are valid and in full force and effect, subject to such qualifications as may be set forth in the Prospectus. The Company has not received any notice of proceedings relating to the revocation or modification of any such Governmental Licenses.

     (u) Title to Property. The Company has good and defensible title to all of its interests in oil and gas properties (other than interests earned under farm-out, participation or similar agreements in which an assignment or transfer is pending) and all other real property owned by the Company, in each case, free and clear of all mortgages, pledges, liens, security interests, claims, restrictions or encumbrances of any kind, except such as (A) are described in the Prospectus, (B) liens and encumbrances under the Credit Agreements, (C) liens and encumbrances under operating agreements, unitization and pooling agreements, production sales contracts, farm-out agreements and other oil and gas exploration participation, production and transportation agreements, in each case that secure payment of amounts not yet due and payable for the performance of other inchoate obligations and are of a scope and nature customary in the oil and gas industry or arise in connection with drilling and production operations, or (D) do not, singly or in the aggregate, materially affect the value of the affected property and do not interfere with the use made and proposed to be made of such property by the Company. All of the leases and subleases of real property that are material to the business of the Company and under which the Company holds properties described in the Prospectus, are in full force and effect, and the Company has not received notice of any material claim of any sort that has been asserted by anyone adverse to the rights of the Company under any of such leases or subleases, or affecting or questioning the rights of the Company to the continued possession of the leased or subleased premises under any such lease or sublease.

     (v) Certain Oil and Gas Matters. Except as described in the Prospectus, as of the date hereof and the Closing Date, (A) all royalties, rentals, deposits and other amounts owed under the oil and gas leases constituting the oil and gas properties of the Company have been properly and timely paid (other than amounts held in routine suspense accounts pending payments), and no material amount of proceeds from the sale or production attributable to the oil and gas properties of the Company are currently being held in suspense by any purchaser thereof, except where such amounts due could not, singly or in the aggregate, have a Material Adverse Change on the Company, and (B) there are no claims under take-or-pay contracts pursuant to which natural gas purchasers have any make-up rights affecting the interests of the Company in its oil and gas properties, except where such claims could not, singly or in the aggregate, have a Material Adverse Change on the Company.

     (w) Investment Company Act. The Company is not, and upon the issuance and sale of the Offered Shares as herein contemplated and the application of the net proceeds therefrom as described in the Prospectus will not be, an “investment company” or an entity “controlled” by an “investment company” as such terms are defined in the Investment Company Act of 1940, as amended.

     (x) Environmental Laws. Except as described in the Registration Statement and the Prospectus, (A) the Company is not in violation of any federal, state or local statute, law, rule, or

regulation relating to pollution or protection of human health or the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata), including, without limitation, laws and regulations relating to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products (collectively, “Hazardous Materials”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “Environmental Laws”), (B) the Company has all permits, authorizations and approvals required under any applicable Environmental Laws for its business and operations and is in compliance with their requirements, (C) to the knowledge of the Company, there are no pending or threatened administrative, regulatory or judicial actions, suits, claims, notices of noncompliance or violation, investigation or proceedings relating to any Environmental Law against the Company and (D) there are no events or circumstances (including any spill, discharge, leak, emission or release of Hazardous Materials) that could reasonably be expected to form the basis of an order for clean up or remediation, or an action, suit or proceeding by any private party or governmental body or agency, against or affecting the Company relating to Hazardous Materials or any Environmental Laws, except in the case of clauses (A), (B), (C) or (D) where such violation, failure to receive required permits, authorizations and approvals or failure to comply with the requirements of such permits, authorizations and approvals, action or liabilities related to Hazardous Materials or any Environmental Laws would not, individually or in the aggregate, have a Material Adverse Change.

     (y) Registration Rights. 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 the Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Securities Act, except for the rights of the holders of the Company’s 10 ¹/4% Senior Notes due 2014 under that certain Registration Rights Agreement, dated July 31, 2007, among the Company, Jefferies & Company, Inc., Merrill Lynch, Pierce, Fenner & Smith Incorporated, and BNP Paribas Securities Corp.

     (z) Stabilizing Transactions. The Company has not taken, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of the Shares or any other “reference security” (as defined in Rule 100 of Regulation M under the Exchange Act (“Regulation M”)) whether to facilitate the sale or resale of the Offered Shares or otherwise, and has taken no action which would directly or indirectly violate Regulation M.

     (aa) Statistical and Market Data. The statistical and market related data included or incorporated by reference in the Registration Statement and the Prospectus are based on or derived from sources that the Company believes to be reliable and accurate or represent the Company’s good faith estimates that are made on the basis of data derived from such sources.

     (bb) Finders’ Fee. Except as disclosed in the Time of Sale Prospectus, the Company knows of no outstanding claims for services, in the nature of a finder’s fee or origination fee or other similar claim, with respect to the transactions contemplated hereby, other than the underwriting fees and compensation to be paid to the Underwriter in accordance with this Agreement.

     (cc) Payment of Taxes. All United States federal income tax returns of the Company and its prior subsidiaries required by law to be filed have been filed (or extensions with respect to such tax returns have been obtained), and all taxes shown by such filed tax returns or otherwise assessed, that are due and payable, have been paid, except those which are being contested in good faith and as to which adequate reserves have been provided in accordance with GAAP, and except for such failures to file returns and pay taxes as could not, individually or in the aggregate, reasonably be expected to have a Material Adverse Change. Except as otherwise disclosed in the Registration Statement and the Prospectus, the Company has not received any notice from the Internal Revenue Service that it intends to audit the Company’s federal income tax returns for any year during the three year period ended December 31, 2006 and no audit proceeding by the Internal Revenue Service has been conducted during such period. The Company and its prior subsidiaries have filed all other tax returns (or obtained extensions with respect to such tax returns) that are required to have been filed by them pursuant to applicable foreign, state, local or other law, and have paid all taxes due pursuant to such returns or pursuant to any assessment received by the Company, except those which are being contested in good faith and as to which adequate reserves have been provided in accordance with GAAP and except for such failures to file returns and pay taxes as could not, individually or in the aggregate, reasonably be expected to have a Material Adverse Change. The charges, accruals and reserves on the books of the Company in respect of any income and corporation tax liability for any years not finally determined have been established to the extent required by GAAP.

     (dd) Company’s Accounting System. The Company makes and keeps accurate books and records and maintains a system of internal accounting controls sufficient to provide reasonable assurance that (i) material transactions are executed in accordance with management’s general or specific authorization; (ii) material transactions are recorded as necessary to permit preparation of financial statements in conformity with GAAP and to maintain accountability for assets; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the recorded accountability for assets is compared with existing assets at reasonable intervals and appropriate action is taken with respect to any material differences. For the year ended December 31, 2006, there has not been a material weakness in the Company’s internal control over financial reporting (whether or not remediated) and since December 31, 2006, there has been no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

     (ee) Insurance. The Company carries, or is covered by, insurance with financially sound and reputable insurers, in such amounts and covering such risks as is reasonably adequate for the conduct of its businesses in accordance with customary industry practice, and all such insurance is in full force and effect.

     (ff) Related Party Transactions. No relationship, direct or indirect, exists between or among any of the Company or any affiliate of the Company, on the one hand, and any director, officer, stockholder, customer or supplier of any of them, on the other hand, which is required by the Securities Act or by the Securities Act Regulations to be described in the Registration Statement or the Prospectus which is not so described or is not described as required.

     (gg) Reserve Reports. The written engineering reserve reports prepared by Cawley, Gillespie & Associates, Inc., an independent petroleum engineering consulting firm (“Cawley Gillespie”), as of December 31, 2006 and June 30, 2007, setting forth the engineering values attributed to the oil and gas properties of the Company and its prior subsidiaries accurately reflect in all material respects the ownership interests of the Company and its prior subsidiaries in the

properties included therein as of December 31, 2006 and June 30, 2007, respectively, except as otherwise disclosed in the Registration Statement and the Prospectus. The information furnished by the Company to Cawley Gillespie for purposes of preparing its reports, including, without limitation, production, costs of operation and development, current prices for production, agreements relating to current and future operations and sales of production, was true, correct and complete in all material respects on the dates supplied and was prepared in accordance with customary industry practices, as indicated in the letters of Cawley Gillespie dated January 29, 2007 and July 18, 2007; Cawley Gillespie is independent with respect to the Company.

     (hh) No Integration. Except as described in the Prospectus or in the documents incorporated by reference into the Prospectus, the Company has not sold or issued any shares of Common Stock during the six month period preceding the date of the Prospectus, including any sales pursuant to Rule 144A under, or Regulations D or S of, the Securities Act, other than shares issued pursuant to employee benefit plans, stock options plans or other officer, director or employee compensation plans or pursuant to outstanding options, convertible preferred stock, rights or warrants.

     (ii) Sarbanes-Oxley. The principal executive officer and principal financial officer of the Company have made all certifications required by the Sarbanes Oxley Act or any related rules and regulations promulgated by the Commission, and the statements contained in any such certification are complete and correct. The Company has established and maintains disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)), which (A) are designed to ensure that material information relating to the Company, including its consolidated subsidiaries, is made known to the Company’s principal executive officer and its principal financial officer by others within those entities, particularly during the periods in which the periodic reports required under the Exchange Act are being prepared; (B) have been evaluated by management of the Company for effectiveness as of a date within 90 days prior to the earlier of the date that the Company filed its most recent annual or quarterly report with the Commission and the date of the Time of Sale Prospectus and the Prospectus; and (C) are effective in all material respects to perform the functions for which they were established. Based on the most recent evaluation of its disclosure controls and procedures, the Company is not aware of (i) any significant deficiencies or material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the Company’s ability to record, process, summarize and report financial information or (ii) any fraud, whether or not material, that involves management or other employees who have a significant role in the Company’s internal control over financial reporting. The Company is not aware of any change in its internal control over financial reporting that has occurred during its most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting. The Company is otherwise in compliance in all material respects with all applicable effective provisions of the Sarbanes Oxley Act and the rules and regulations promulgated by the Commission.

     (jj) Corrupt Practices. Neither the Company nor any director, officer, agent, employee or other person acting on behalf of the Company, has used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; made any direct or indirect unlawful payment to any foreign or domestic government official or employee from corporate funds; violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977; or made any bribe, rebate, payoff, influence payment, kickback or other unlawful payment.

     (kk) Money Laundering Laws. The operations of the Company are, and have been conducted at all times, in compliance with applicable financial recordkeeping and reporting requirements of the Currency and Foreign Transactions Reporting Act of 1970, as amended, the money laundering statutes of all applicable jurisdictions, the rules and regulations thereunder and any related or similar applicable rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Money Laundering Laws”) and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company with respect to the Money Laundering Laws is pending or, to the best knowledge of the Company, threatened.

     (ll) OFAC. Neither the Company nor, to the knowledge of the Company, any director, officer, agent, employee, affiliate or person acting on behalf of the Company is currently subject to any U.S. sanctions administered by the Office of Foreign Assets Control of the U.S. Treasury Department (“OFAC”); and the Company will not directly or indirectly use the proceeds of this offering, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity, for the purpose of financing the activities of any person currently subject to any U.S. sanctions administered by OFAC.

     Any certificate signed by any officer of the Company and delivered to the Underwriter or to counsel for the Underwriter shall be deemed a representation and warranty by the Company to the Underwriter as to the matters covered thereby.

     The Company acknowledges that the Underwriter and, for purposes of the opinions to be delivered pursuant to Section 6 hereof, counsel to the Company and counsel to the Underwriter, will rely upon the accuracy and truthfulness of the foregoing representations and hereby consents to such reliance.

     Section 2. Purchase, Sale and Delivery of the Offered Shares.

     (a) The Offered Shares. Upon the terms herein set forth, the Company agrees to issue and sell to the Underwriter an aggregate of 3,000,000 Offered Shares. On the basis of the representations, warranties and agreements herein contained, and upon the terms but subject to the conditions herein set forth, the Underwriter agrees to purchase from the Company the Offered Shares. The purchase price per Offered Share to be paid by the Underwriter to the Company shall be $17.84 per share.

     (b) The Closing Date. Delivery of certificates for the Offered Shares to be purchased by the Underwriter and payment therefor shall be made at the offices of the Underwriter, 520 Madison Avenue, New York, New York (or such other place as may be agreed to by the Company and the Underwriter) at 9:00 a.m. New York time, on December 6, 2007, or such other time and date not later than 1:30 p.m. New York time, on December 6, 2007 as the Underwriter shall designate by notice to the Company (the time and date of such closing are called the “Closing Date”). The Company hereby acknowledges that circumstances under which the Underwriter may provide notice to postpone the Closing Date as originally scheduled include, but are in no way limited to, any determination by the Company or the Underwriter to recirculate to the public copies of an amended or supplemented Prospectus.

     (c) Public Offering of the Offered Shares. The Underwriter hereby advises the Company that the Underwriter intends to offer for sale to the public, initially on the terms set forth in the Time of Sale Prospectus and the Prospectus, the Offered Shares as soon after this Agreement has been executed and the Underwriter, in its sole judgment, has determined is

advisable and practicable. The Company and the Underwriter have agreed that the information set forth on Schedule A hereto shall be orally conveyed by the Underwriter to each purchaser of Offered Shares (such information, the “Scripted Information”) prior to the Underwriter confirming any sales of such Offered Shares.

     (d) Payment for the Offered Shares. Payment for the Offered Shares to be sold by the Company shall be made at the Closing Date by wire transfer of immediately available funds to the order of the Company.

     It is understood that the Underwriter has been authorized, for its own account, to accept delivery of and receipt for, and make payment of the purchase price for, the Offered Shares the Underwriter has agreed to purchase.

     (e) Delivery of the Offered Shares. The Company shall deliver, or cause to be delivered, to the Underwriter for the account of the Underwriter certificates for the Offered Shares to be sold by it at the Closing Date, against the irrevocable release of a wire transfer of immediately available funds for the amount of the purchase price therefor. The certificates for the Offered Shares shall be in definitive form and registered in such names and denominations as the Underwriter shall have requested at least two full business days prior to the Closing Date and shall be made available for inspection on the business day preceding the Closing Date at a location in New York City as the Underwriter may designate. Time shall be of the essence, and delivery at the time and place specified in this Agreement is a further condition to the obligations of the Underwriter.

     Section 3. Additional Covenants of the Company.

     The Company further covenants and agrees with the Underwriter as follows:

     (a) Delivery of Registration Statement, Time of Sale Prospectus and Prospectus. The Company shall furnish to you, without charge, copies of the Registration Statement, any amendments thereto and shall furnish to you in New York City, without charge, prior to 10:00 a.m. New York City time on the business day next succeeding the date of this Agreement and during the period mentioned in Section 3(e) or 3(f) below, as many copies of the Time of Sale Prospectus, the Prospectus and any supplements and amendments thereto or to the Registration Statement as you may reasonably request.

     (b) Underwriter’s Review of Proposed Amendments and Supplements. Prior to amending or supplementing the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus or the Prospectus (including any amendment or supplement through incorporation of any report filed under the Exchange Act), the Company shall furnish to the Underwriter for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of each such proposed amendment or supplement, and the Company shall not file or use any such proposed amendment or supplement without the Underwriter’s consent, and to file with the Commission within the applicable period specified in Rule 424(b) under the Securities Act any prospectus required to be filed pursuant to such Rule.

     (c) Free Writing Prospectuses. The Company shall furnish to the Underwriter for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of each proposed free writing prospectus or any amendment or supplement thereto to be prepared by or on behalf of, used by, or referred to by the Company and the Company shall not file, use or refer to any proposed free writing prospectus or any amendment or supplement thereto without

the Underwriter’s consent. The Company shall furnish to the Underwriter, without charge, as many copies of any free writing prospectus prepared by or on behalf of, or used by the Company, as the Underwriter may reasonably request. If at any time when a prospectus is required by the Securities Act (including, without limitation, pursuant to Rule 173(d)) to be delivered in connection with sales of the Offered Shares (but in any event if at any time through and including the Closing Date) there occurred or occurs an event or development as a result of which any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company conflicted or would conflict with the information contained in the Registration Statement or included or would include an untrue statement of a material fact or omitted or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at that subsequent time, not misleading, the Company shall promptly amend or supplement such free writing prospectus to eliminate or correct such conflict so that the statements in such free writing prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at such subsequent time, not misleading, as the case may be; provided, however, that prior to amending or supplementing any such free writing prospectus, the Company shall furnish to the Underwriter for review, a reasonable amount of time prior to the proposed time of filing or use thereof, a copy of such proposed amended or supplemented free writing prospectus and the Company shall not file, use or refer to any such amended or supplemented free writing prospectus without the Underwriter’s consent.

     (d) Filing of Underwriter Free Writing Prospectuses. The Company shall not take any action that would result in the Underwriter or the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that the Underwriter otherwise would not have been required to file thereunder.

     (e) Amendments and Supplements to Time of Sale Prospectus. If the Time of Sale Prospectus is being used to solicit offers to buy the Shares at a time when the Prospectus is not yet available to prospective purchasers and any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Time of Sale Prospectus so that the Time of Sale Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading, or if any event shall occur or condition exist as a result of which the Time of Sale Prospectus conflicts with the information contained in the Registration Statement, or if, in the opinion of counsel for the Underwriter, it is necessary to amend or supplement the Time of Sale Prospectus to comply with applicable law, including the Securities Act, the Company shall (subject to Sections 3(b) and 3(c)) forthwith prepare, file with the Commission and furnish, at its own expense, to the Underwriter and to any dealer upon request, either amendments or supplements to the Time of Sale Prospectus so that the statements in the Time of Sale Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when delivered to a prospective purchaser, not misleading or so that the Time of Sale Prospectus, as amended or supplemented, will no longer conflict with the Registration Statement, or so that the Time of Sale Prospectus, as amended or supplemented, will comply with applicable law including the Securities Act.

     (f) Securities Act Compliance. After the date of this Agreement, the Company shall promptly advise the Underwriter in writing (i) of the receipt of any comments of, or requests for additional or supplemental information from, the Commission, (ii) of the time and date of any filing of any post-effective amendment to the Registration Statement, or any amendment or

supplement to the Preliminary Prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus, (iii) of the time and date that any post-effective amendment to the Registration Statement becomes effective and (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any post-effective amendment thereto, or any amendment or supplement to any Preliminary Prospectus, the Time of Sale Prospectus or the Prospectus or of any order preventing or suspending the use of any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus or the Prospectus, or of any proceedings to remove, suspend or terminate from listing or quotation the Shares from any securities exchange upon which they are listed for trading or included or designated for quotation, or of the threatening or initiation of any proceedings for any of such purposes. If the Commission shall enter any such stop order at any time, the Company will use its reasonable best efforts to obtain the lifting of such order at the earliest possible moment. Additionally, the Company agrees that it shall comply with the provisions of Rule 424(b), Rule 433 and Rule 430A, as applicable, under the Securities Act and will use its reasonable efforts to confirm that any filings made by the Company under such Rule 424(b) or Rule 433 were received in a timely manner by the Commission.

     (g) Amendments and Supplements to the Prospectus and Other Securities Act Matters. If any event shall occur or condition exist as a result of which it is necessary to amend or supplement the Prospectus so that the Prospectus does not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered to a purchaser, not misleading, or if in the opinion of the Underwriter or counsel for the Underwriter it is otherwise necessary to amend or supplement the Prospectus to comply with applicable law, including the Securities Act, the Company agrees (subject to Section 3(b) and 3(c)) to promptly prepare, file with the Commission and furnish at its own expense to the Underwriter and to dealers, amendments or supplements to the Prospectus so that the statements in the Prospectus as so amended or supplemented will not include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances when the Prospectus is delivered to a purchaser, not misleading or so that the Prospectus, as amended or supplemented, will comply with applicable law including the Securities Act. Neither the Underwriter’s consent to, or delivery of, any such amendment or supplement shall constitute a waiver of any of the Company’s obligations under Sections 3(b) or (c).

     (h) Blue Sky Compliance. The Company shall cooperate with the Underwriter and counsel for the Underwriter to qualify or register the Offered Shares for sale under (or obtain exemptions from the application of) those jurisdictions designated by the Underwriter, and shall comply with such laws and shall continue such qualifications, registrations and exemptions in effect so long as required for the distribution of the Offered Shares. The Company shall not be required to qualify as a foreign corporation or to take any action that would subject it to general service of process in any such jurisdiction where it is not presently qualified or where it would be subject to taxation as a foreign corporation. The Company will advise the Underwriter promptly of the suspension of the qualification or registration of (or any such exemption relating to) the Offered Shares for offering, sale or trading in any jurisdiction or any initiation or threat of any proceeding for any such purpose, and in the event of the issuance of any order suspending such qualification, registration or exemption, the Company shall use its best efforts to obtain the withdrawal thereof at the earliest possible moment.

     (i) Use of Proceeds. The Company shall apply the net proceeds from the sale of the Offered Shares sold by it in the manner described under the caption “Use of Proceeds” in the Prospectus.

     (j) Transfer Agent. The Company shall engage and maintain, at its expense, a registrar and transfer agent for the Shares.

     (k) Earnings Statement. As soon as practicable, but in any event no later than twelve months after the date of this Agreement, the Company will make generally available to its security holders and to the Underwriter an earnings statement (which need not be audited) covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the date of this Agreement which shall satisfy the provisions of Section 11(a) of the Securities Act and the rules and regulations of the Commission thereunder.

     (l) Periodic Reporting Obligations. The Company shall file, on a timely basis, with the Commission and the Nasdaq Global Market all reports and documents required to be filed under the Exchange Act. Additionally, the Company shall report the use of proceeds from the issuance of the Offered Shares as may be required under Rule 463 under the Securities Act.

     (m) Listing. The Company will use its best efforts to maintain the listing of the Offered Shares and the Shares on the Nasdaq Global Market.

     (n) Company to Provide Copy of the Prospectus in Form That May be Downloaded from the Internet. The Company shall cause to be prepared and delivered, at its expense, within one business day from the effective date of this Agreement, to the Underwriter an “electronic Prospectus” to be used by the Underwriter in connection with the offering and sale of the Offered Shares. As used herein, the term “electronic Prospectus” means a form of Time of Sale Prospectus, and any amendment or supplement thereto, that meets each of the following conditions: (i) it shall be encoded in an electronic format, satisfactory to the Underwriter, that may be transmitted electronically by the Underwriter to offerees and purchasers of the Offered Shares; (ii) it shall disclose the same information as the paper Time of Sale Prospectus, except to the extent that graphic and image material cannot be disseminated electronically, in which case such graphic and image material shall be replaced in the electronic Prospectus with a fair and accurate narrative description or tabular representation of such material, as appropriate; and (iii) it shall be in or convertible into a paper format or an electronic format, satisfactory to the Underwriter, that will allow investors to store and have continuously ready access to the Time of Sale Prospectus at any future time, without charge to investors (other than any fee charged for subscription to the Internet as a whole and for on-line time). The Company hereby confirms that it has included or will include in the Prospectus filed pursuant to EDGAR or otherwise with the Commission and in the Registration Statement at the time it was declared effective an undertaking that, upon receipt of a request by an investor or his or her representative, the Company shall transmit or cause to be transmitted promptly, without charge, a paper copy of the Time of Sale Prospectus.

     (o) Agreement Not to Offer or Sell Additional Shares. During the period commencing on and including the date hereof and ending on and including the 60th day following the date of this Agreement (as the same may be extended as described below, the “Lock-up Period”), the Company will not, without the prior written consent of the Underwriter (which consent may be withheld at the sole discretion of the Underwriter), directly or indirectly, sell (including, without limitation, any short sale), offer, contract or grant any option to sell, pledge, transfer or establish an open “put equivalent position” within the meaning of Rule 16a-1(h) under the Exchange Act, or otherwise dispose of or transfer, or announce the offering of, or file any registration statement under the Securities Act in respect of, any Shares, options, rights or warrants to acquire Shares or securities exchangeable or exercisable for or convertible into Shares (other than as contemplated by this Agreement with respect to the Offered Shares) or publicly

announce the intention to do any of the foregoing; provided, however, that the Company may issue Shares or options to purchase Shares, or issue Shares upon exercise of options, pursuant to any stock option, stock bonus or other stock plan or arrangement described in each Prospectus, but only if the holders of such shares, options, or shares issued upon exercise of such options, agree in writing not to sell, offer, dispose of or otherwise transfer any such shares or options during such Lock-up Period without the prior written consent of the Underwriter (which consent may be withheld at the sole discretion of the Underwriter). Notwithstanding the foregoing, if (i) during the last 17 days of the Lock-up Period, the Company issues an earnings release or material news or a material event relating to the Company occurs or (ii) prior to the expiration of the Lock-up Period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 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 the issuance of the earnings release or the occurrence of the material news or material event, as applicable, unless the Underwriter waives, in writing, such extension (which waiver may be withheld at the sole discretion of the Underwriter), except that such extension will not apply if, (i) within three business days prior to the 15th calendar day before the last day of the Lock-up Period, the Company delivers a certificate, signed by the Chief Financial Officer or Chief Executive Officer of the Company, certifying on behalf of the Company that (i) the Shares are “actively traded securities” (as defined in Regulation M), (ii) the Company meets the applicable requirements of paragraph (a)(1) of Rule 139 under the Securities Act in the manner contemplated by NASD Conduct Rule 2711(f)(4), and (iii) the provisions of NASD Conduct Rule 2711(f)(4) are not applicable to any research reports relating to the Company published or distributed by the Underwriter during the 15 days before or after the last day of the Lock-up Period (before giving effect to such extension). The Company will provide the Underwriter with prior notice of any such announcement that gives rise to an extension of the Lock-up Period.

     (p) Investment Company Act. The Company will take such steps as shall be necessary to ensure that the Company shall not become an “investment company” as defined in the Investment Company Act.

     (q) No Stabilization or Manipulation; Compliance with Regulation M. The Company will not take, directly or indirectly, any action designed to or that might be reasonably expected to cause or result in stabilization or manipulation of the price of the Shares or any other reference security, whether to facilitate the sale or resale of the Offered Shares or otherwise, and the Company will, and shall cause each of its affiliates to, comply with all applicable provisions of Regulation M. If the limitations of Rule 102 of Regulation M (“Rule 102”) do not apply with respect to the Offered Shares or any other reference security pursuant to any exception set forth in Section (d) of Rule 102, then promptly upon notice from the Underwriter (or, if later, at the time stated in the notice), the Company will, and shall cause each of its affiliates to, comply with Rule 102 as though such exception were not available but the other provisions of Rule 102 (as interpreted by the Commission) did apply.

     The Underwriter may, in its sole discretion, waive in writing the performance by the Company of any one or more of the foregoing covenants or extend the time for their performance.

     Section 4. Payment of Expenses. The Company agrees to pay for itself all costs, fees and expenses incurred in connection with the performance of its obligations hereunder and in connection with the transactions contemplated hereby, including without limitation (i) all expenses incident to the issuance and delivery of the Offered Shares (including all printing and engraving costs), (ii) all fees and expenses of the registrar and transfer agent of the Shares, (iii) all necessary issue, transfer and other stamp taxes in connection with the issuance and sale of the Offered Shares to the Underwriter, (iv) all fees and expenses

of the Company’s counsel, independent public or certified public accountants and other advisors, (v) all costs and expenses incurred in connection with the preparation, printing, filing, shipping and distribution of the Registration Statement (including financial statements, exhibits, schedules, consents and certificates of experts), the Time of Sale Prospectus, the Prospectus, any free writing prospectus prepared by or on behalf of, used by, or referred to by the Company, each preliminary prospectus, and all amendments and supplements thereto, and this Agreement, (vi) all filing fees, attorneys’ fees and expenses incurred by the Company or the Underwriter in connection with qualifying or registering (or obtaining exemptions from the qualification or registration of) all or any part of the Offered Shares for offer and sale under the state securities or blue sky laws or the provincial securities laws of Canada, and, if requested by the Underwriter, preparing and printing a “Blue Sky Survey” or memorandum and a “Canadian wrapper”, and any supplements thereto, advising the Underwriter of such qualifications, registrations, determinations and exemptions, (vii) the filing fees incident to, and the reasonable fees and expenses of counsel for the Underwriter in connection with, the NASD’s review, if any, and approval of the Underwriter’s participation in the offering and distribution of the Offered Shares, (viii) the costs and expenses of the Company relating to investor presentations on any “road show” undertaken in connection with the marketing of the offering of the Offered Shares, including, without limitation, expenses associated with the preparation or dissemination of any electronic road show, expenses associated with the production of road show slides and graphics, fees and expenses of any consultants engaged in connection with the road show presentations with the prior approval of the Company, travel and lodging expenses of the representatives, employees and officers of the Company and of the Underwriter and any such consultants, and the cost of any aircraft chartered in connection with the road show, (ix) the fees and expenses associated with including the Offered Shares on the Nasdaq Global Market, and (ix) all other fees, costs and expenses of the nature referred to in Item 14 of Part II of the Registration Statement. Except as provided in this Section 4, Section 7, Section 9 and Section 10 hereof, the Underwriter shall pay its own expenses, including the fees and disbursements of its counsel.

     Section 5. Covenant of the Underwriter. The Underwriter covenants with the Company not to take any action that would result in the Company being required to file with the Commission pursuant to Rule 433(d) under the Securities Act a free writing prospectus prepared by or on behalf of the Underwriter that otherwise would not be required to be filed by the Company thereunder, but for the action of the Underwriter; provided, however, that the Underwriter is authorized to use the Scripted Information in communications conveying information relating to the offering to investors.

     Section 6. Conditions of the Obligations of the Underwriter. The obligations of the Underwriter to purchase and pay for the Offered Shares as provided herein on the Closing Date shall be subject to the accuracy of the representations and warranties on the part of the Company set forth in Section 1 hereof as of the date hereof and as of the Closing Date as though then made, to the timely performance by the Company of its covenants and other obligations hereunder, and to each of the following additional conditions:

     (a) Accountants’ Comfort Letter. On the date of the execution of this Agreement, the Underwriter shall have received from BDO Seidman, LLP, independent public or certified public accountants for the Company, (i) a letter dated the date hereof addressed to the Underwriter, in form and substance satisfactory to the Underwriter, containing statements and information of the type ordinarily included in accountant’s “comfort letters” to underwriters, delivered according to Statement of Auditing Standards No. 72 (or any successor bulletin), with respect to the audited and unaudited financial statements (including the financial statements of certain acquisitions incorporated by reference in the Registration Statement) and certain financial information contained in the Registration Statement, the Preliminary Prospectus, Time of Sale Prospectus, and each free writing prospectus, if any, and, with respect to each letter dated the date hereof only, the Prospectus, and (ii) confirming that they are (A) independent public or certified

public accountants as required by the Securities Act and the Exchange Act and (B) in compliance with the applicable requirements relating to the qualification of accountants under Rule 2-01 of Regulation S-X.

     (b) Compliance with Registration Requirements; No Stop Order; No Objection from NASD. For the period from and after effectiveness of this Agreement and prior to the Closing Date:

     (i) the Company shall have filed the Prospectus with the Commission (including the information required by Rule 430A previously omitted from the Registration Statement pursuant to Rule 430B under the Securities Act) in the manner and within the time period required by Rule 424(b) under the Securities Act;

     (ii) no stop order suspending the effectiveness of the Registration Statement, or any post-effective amendment to the Registration Statement, shall be in effect and no proceedings for such purpose shall have been instituted or threatened by the Commission and any request on the part of the Commission for additional information shall have been complied with; and

     (iii) the NASD shall have raised no objection to the fairness and reasonableness of the underwriting terms and arrangements.

     (c) No Material Adverse Change or Ratings Agency Change. For the period from and after the date of this Agreement and through and including the Closing Date:

     (i) in the reasonable judgment of the Underwriter there shall not have occurred any Material Adverse Change; and

     (ii) (A) there shall not have occurred any downgrading, suspension or withdrawal of, nor shall any notice have been given of any intended or potential downgrading, suspension or withdrawal of, or of any review (or of any potential or intended review) for a possible change that does not indicate the direction of the possible change in, any rating of the Company or any securities of the Company (including, without limitation, the placing of any of the foregoing ratings on credit watch with negative or developing implications or under review with an uncertain direction) by any “nationally recognized statistical rating organization” as such term is defined for purposes of Rule  436(g)(2) under the Securities Act, and (B) there shall not have occurred any change, nor shall any notice have been given of any potential or intended change, in the outlook for any rating of the Company or any securities of the Company by any such rating organization.

     (d) Opinion of Counsel for the Company. On the Closing Date, the Underwriter shall have received the opinions of each of Haynes and Boone, LLP, special counsel for the Company, and Lynch, Chappell & Alsup, P.C., counsel for the Company, dated as of the Closing Date, the forms of which are attached as Exhibit A and to such further effect as counsel for the Underwriter shall reasonably request.

     (e) Opinion of Counsel for the Underwriter. On the Closing Date, the Underwriter shall have received the opinion of Vinson & Elkins L.L.P., counsel for the Underwriter, in form and substance reasonably satisfactory to the Underwriter, dated as of such Closing Date.

     (f) Officers’ Certificate. On the Closing Date, the Underwriter shall have received a written certificate executed by the Chief Executive Officer or President of the Company and the Chief Financial Officer of the Company, dated as of such Closing Date, to the effect set forth in subsections (b)(ii) and (c)(ii) of this Section 6, and further to the effect that:

     (i) for the period from and including the date of this Agreement through and including such Closing Date, there has not occurred any Material Adverse Change;

     (ii) the representations, warranties and covenants of the Company set forth in Section 1 of this Agreement are true and correct with the same force and effect as though expressly made on and as of such Closing Date; and

     (iii) the Company has complied with all the agreements hereunder and satisfied all the conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date.

     (g) Bring-down Comfort Letter. On the Closing Date, the Underwriter shall have received from BDO Seidman, LLP, independent public or certified public accountants for the Company, a letter dated such date, in form and substance satisfactory to the Underwriter, to the effect that they reaffirm the statements made in the letter furnished by them pursuant to subsection (a) of this Section 6, except that the specified date referred to therein for the carrying out of procedures shall be no more than three business days prior to the Closing Date.

     (h) Lock-Up Agreement from Certain Securityholders of the Company. On or prior to the date hereof, the Company shall have furnished to the Underwriter an agreement in the form of Exhibit B hereto from each director and executive officer of the Company, and such agreement shall be in full force and effect on the Closing Date.

     (i) Misstatement or Omission. The Underwriter shall not have discovered and disclosed to the Company on or prior to the Closing Date that the Registration Statement or the Prospectus, or any amendment or supplement thereto, contains an untrue statement of a fact which, in the opinion of counsel for the Underwriter, is material or omits to state a fact which, in the opinion of such counsel, is material and is required to be stated therein or is necessary to make the statements therein not misleading.

     (j) Reserve Engineer’s Letter. At the time of execution of this Agreement, the Underwriter shall have received from Cawley, Gillespie & Associates, Inc., independent petroleum engineers, a letter, in form and substance satisfactory to the Underwriter and its counsel to the effect that with respect to the Company they are independent petroleum engineers and confirming certain reserve information included in the Registration Statement and Prospectus.

     (k) Bring-Down Reserve Engineer’s Letter. At the Closing Date, the Underwriter shall have received from Cawley, Gillespie & Associates, Inc. a letter, dated as of Closing Date, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (j) of this Section, except that the specified date referred to shall be dated the Closing Date.

     (l) Maintenance of Listing. At the Closing Date, the Company shall have maintained a listing of the Company’s common stock on the Nasdaq Global Market.

     (m) Additional Documents. On or before the Closing Date, the Underwriter and Vinson & Elkins L.L.P. shall have received such information, documents and opinions as they may reasonably request for the purposes of enabling them to pass upon the issuance and sale of the Offered Shares as contemplated herein, or in order to evidence the accuracy of any of the representations and warranties, or the satisfaction of any of the conditions or agreements, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Offered Shares as contemplated herein and in connection with the other transactions contemplated by this Agreement shall be satisfactory in form and substance to the Underwriter and Vinson & Elkins L.L.P.

     If any condition specified in this Section 6 is not satisfied when and as required to be satisfied, this Agreement may be terminated by the Underwriter by notice to the Company at any time on or prior to the Closing Date which termination shall be without liability on the part of any party to any other party, except that Section 4, Section 6, Section 8 and Section 9 shall at all times be effective and shall survive such termination.

     Section 7. Reimbursement of Underwriter Expenses. If this Agreement is terminated by the Underwriter pursuant to Section 6 or Section 11, or if the sale to the Underwriter of the Offered Shares on the Closing Date is not consummated because of any refusal, inability or failure on the part of the Company to perform any agreement herein or to comply with any provision hereof, the Company agrees to reimburse the Underwriter upon demand for all out-of-pocket expenses that shall have been reasonably incurred by the Underwriter in connection with the proposed purchase and the offering and sale of the Offered Shares, including but not limited to fees and disbursements of counsel, printing expenses, travel expenses, postage, facsimile and telephone charges.

     Section 8. Effectiveness of this Agreement. This Agreement shall become effective upon the execution of this Agreement by the parties hereto.

     Section 9. Indemnification.

     (a) Indemnification of the Underwriter. The Company agrees to indemnify and hold harmless the Underwriter, its officers and employees, and each person, if any, who controls the Underwriter within the meaning of the Securities Act or the Exchange Act against any loss, claim, damage, liability or expense, as incurred, to which such Underwriter or such officer, employee or controlling person may become subject, under the Securities Act, the Exchange Act, other federal or state statutory law or regulation, or the laws or regulations of foreign jurisdictions where Offered Shares have been offered or sold or at common law or otherwise (including in settlement of any litigation), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or any amendment thereto, including any information deemed to be a part thereof pursuant to Rule 430A under the Securities Act, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading; or (ii) any untrue statement or alleged untrue statement of a material fact contained in any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act or the Prospectus (or any amendment or supplement thereto), or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; or (iii) any act or failure to act or any alleged act or failure to act by any Underwriter in connection with, or relating in any manner to, the Offered Shares or the offering contemplated hereby, and which is included as part of or referred to in any

loss, claim, damage, liability or action arising out of or based upon any matter covered by clause (i) or (ii) above, provided that the Company shall not be liable under this clause (iii) to the extent that a court of competent jurisdiction shall have determined by a final judgment that such loss, claim, damage, liability or action resulted directly from any such acts or failures to act undertaken or omitted to be taken by such Underwriter through its bad faith or willful misconduct; and to reimburse the Underwriter and each such officer, employee and controlling person for any and all expenses (including the fees and disbursements of counsel chosen by the Underwriter) as such expenses are reasonably incurred by such Underwriter or such officer, employee or controlling person in connection with investigating, defending, settling, compromising or paying (subject to paragraph (d) below) any such loss, claim, damage, liability, expense or action; provided, however, that the foregoing indemnity agreement shall not apply to any loss, claim, damage, liability or expense to the extent, but only to the extent, arising out of or based upon (x) any untrue statement or alleged untrue statement or omission or alleged omission made in reliance upon and in conformity with written information furnished to the Company by or on behalf of the Underwriter expressly for use in the Registration Statement, the Time of Sale Prospectus, any such free writing prospectus or the Prospectus (or any amendment or supplement thereto), it being understood and agreed that the only such information furnished by the Underwriter to the Company consists of the information described in subsection (b) below or (y) the failure of the Underwriter to convey the Scripted Information as contemplated by Section 2(c). The indemnity agreement set forth in this Section 9(a) shall be in addition to any liabilities that the Company may otherwise have.

     (b) Indemnification of the Company, its Directors and Officers. The Underwriter agrees to indemnify and hold harmless the Company, each of its directors, each of its officers who signed the Registration Statement, and each person, if any, who controls the Company within the meaning of the Securities Act or the Exchange Act, against any loss, claim, damage, liability or expense, as incurred, to which the Company, or any such director, officer or controlling person may become subject, under the Securities Act, the Exchange Act, or other federal or state statutory law or regulation, or at common law or otherwise (including in settlement of any litigation, if such settlement is effected with the written consent of such Underwriter), insofar as such loss, claim, damage, liability or expense (or actions in respect thereof as contemplated below) arises out of or is based upon any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act or the Prospectus (or such amendment or supplement thereto), or arises out of or is 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, 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 the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, such free writing prospectus that the Company has used, referred to or filed, or is required to file, pursuant to Rule 433(d) of the Securities Act, the Prospectus (or such amendment or supplement thereto), in reliance upon and in conformity with written information furnished to the Company by or on behalf of the Underwriter expressly for use therein; and to reimburse the Company, or any such director, officer or controlling person for any legal and other expense reasonably incurred by the Company, or any such director, officer or controlling person in connection with investigating, defending, settling, compromising or paying (subject to paragraph (d) below) any such loss, claim, damage, liability, expense or action. The Company hereby acknowledges that the only information that the Underwriter has furnished to the Company expressly for use in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, any free writing prospectus that the Company has filed, or is required to file, pursuant to Rule 433(d) of the

Securities Act or the Prospectus (or any amendment or supplement thereto) are the statements set forth under the caption “Underwriting” in the Prospectus concerning stabilization and electronic distribution by the Underwriter. The indemnity agreement set forth in this Section 9(b) shall be in addition to any liabilities that each Underwriter may otherwise have.

     (c) Notifications and Other Indemnification Procedures. Promptly after receipt by an indemnified party under this Section 9 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 this Section 9, notify the indemnifying party in writing of the commencement thereof, but the omission so to notify the indemnifying party will not relieve it from any liability which it may have to any indemnified party for contribution or otherwise under the indemnity agreement contained in this Section 9 to the extent it is not materially prejudiced as a proximate result of such failure. In case any such action is brought against any indemnified party and such indemnified party seeks or intends to seek indemnity from an indemnifying party, the indemnifying party will be entitled to participate in, and, to the extent that it shall elect, jointly with all other indemnifying parties similarly notified, by written notice delivered to the indemnified party promptly after receiving the aforesaid notice from such indemnified party, to assume the defense thereof with counsel reasonably satisfactory to such indemnified party; provided, however, if the defendants in any such action include both the indemnified party and the indemnifying party and the indemnified party shall have reasonably concluded that a conflict may arise between the positions of the indemnifying party and the indemnified party in conducting the defense of any such action or that there may be legal defenses available to it and/or other indemnified parties which are different from or additional to those available to the indemnifying party, the indemnified party or parties shall have the right to select separate counsel to assume such legal defenses and to otherwise participate in the defense of such action on behalf of such indemnified party or parties. Upon receipt of notice from the indemnifying party to such indemnified party of such indemnifying party’s election so to assume the defense of such action the indemnifying party will not be liable to such indemnified party under this Section 9 for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof unless (i) the indemnified party shall have employed separate counsel in accordance with the proviso to the preceding sentence (it being understood, however, that the indemnifying party shall not be liable for the fees and expenses of more than one separate counsel (together with local counsel), representing the indemnified parties who are parties to such action), which counsel (together with any local counsel) for the indemnified parties shall be selected by the Underwriter (in the case of counsel for the indemnified parties referred to in Section 9(a) above) or by the Company (in the case of counsel for the indemnified parties referred to in Section 9(b) above)), (ii) the indemnifying party shall not have assumed the defense of such action within a reasonable time after notice of commencement of the action or (iii) the indemnifying party shall not have employed counsel satisfactory to the indemnified party to represent the indemnified party within a reasonable time after notice of commencement of the action, in each of which cases the fees and expenses of counsel shall be at the expense of the indemnifying party and shall be paid as they are incurred.

     (d) Settlements. The indemnifying party under this Section 9 shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the indemnifying party agrees to indemnify the indemnified party against any loss, claim, damage, liability or expense by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel as contemplated by Section 9(c) hereof, the indemnifying party agrees that it shall be liable for any settlement of any proceeding effected without its written

consent if (i) such settlement is entered into more than 30 days after receipt by such indemnifying party of the aforesaid request and (ii) such indemnifying party shall not have reimbursed the indemnified party in accordance with such request prior to the date of such settlement. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement, compromise or consent to the entry of judgment in any pending or threatened action, suit or proceeding in respect of which any indemnified party is or could have been a party and indemnity was or could have been sought hereunder by such indemnified party, unless such settlement, compromise or consent includes an unconditional release of such indemnified party from all liability on claims that are the subject matter of such action, suit or proceeding.

     Section 10. Contribution. If the indemnification provided for in Section 9 is for any reason held to be unavailable to or otherwise insufficient to hold harmless an indemnified party in respect of any losses, claims, damages, liabilities or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount paid or payable by such indemnified party, as incurred, as a result of any losses, claims, damages, liabilities or expenses referred to therein (i) in such proportion as is appropriate to reflect the relative benefits received by the Company, on the one hand, and the Underwriter, on the other hand, from the offering of the Offered Shares pursuant to this Agreement 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, on the one hand, and the Underwriter, on the other hand, in connection with the statements or omissions which resulted in such losses, claims, damages, liabilities or expenses, as well as any other relevant equitable considerations. The relative benefits received by the Company, on the one hand, and the Underwriter, on the other hand, in connection with the offering of the Offered Shares pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Offered Shares pursuant to this Agreement (before deducting expenses) received by the Company, and the total underwriting discounts and commissions received by the Underwriter, in each case as set forth on the front cover page of the Prospectus bear to the aggregate public offering price of the Offered Shares as set forth on such cover. The relative fault of the Company, on the one hand, and the Underwriter, on the other hand, shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company, on the one hand, or the Underwriter, on the other hand, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

     The amount paid or payable by a party as a result of the losses, claims, damages, liabilities and expenses referred to above shall be deemed to include, subject to the limitations set forth in Section 9(c), any legal or other fees or expenses reasonably incurred by such party in connection with investigating or defending any action or claim. The provisions set forth in Section 9(c) with respect to notice of commencement of any action shall apply if a claim for contribution is to be made under this Section 10; provided, however, that no additional notice shall be required with respect to any action for which notice has been given under Section 9(c) for purposes of indemnification.

     The Company and the Underwriter agree that it would not be just and equitable if contribution pursuant to this Section 10 were determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to in this Section 10.

     Notwithstanding the provisions of this Section 10, the Underwriter shall not be required to contribute any amount in excess of the underwriting discounts and commissions received by it in connection with the Offered Shares underwritten by it and distributed to the public. 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. For purposes of

this Section 10, each officer and employee of the Underwriter and each person, if any, who controls the Underwriter within the meaning of the Securities Act or the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, and each person, if any, who controls the Company with the meaning of the Securities Act and the Exchange Act shall have the same rights to contribution as the Company.

     Section 11. Termination of this Agreement. Prior to the purchase of the Offered Shares by the Underwriter on the Closing Date, this Agreement may be terminated by the Underwriter by notice given to the Company if at any time (i) trading or quotation in any of the Company’s securities shall have been suspended or limited by the Commission or by the Nasdaq Global Market, or trading in securities generally on either the Nasdaq Global Market or the New York Stock Exchange shall have been suspended or limited, or minimum or maximum prices shall have been generally established on any of such stock exchanges by the Commission or the NASD; (ii) a general banking moratorium shall have been declared by any of federal, New York, Delaware, Texas or California authorities; (iii) there shall have occurred any outbreak or escalation of national or international hostilities or any crisis or calamity, or any change in the United States or international financial markets, or any substantial change or development involving a prospective substantial change in United States’ or international political, financial or economic conditions, as in the judgment of the Underwriter is material and adverse and makes it impracticable or inadvisable to market the Offered Shares in the manner and on the terms described in the Time of Sale Prospectus or the Prospectus or to enforce contracts for the sale of securities; (iv) in the judgment of the Underwriter there shall have occurred any Material Adverse Change; or (v) the Company shall have sustained a loss by strike, fire, flood, earthquake, accident or other calamity of such character as in the judgment of the Underwriter may interfere materially with the conduct of the business and operations of the Company regardless of whether or not such loss shall have been insured. Any termination pursuant to this Section 11 shall be without liability on the part of (a) the Company to any Underwriter, except that the Company shall be obligated to reimburse the expenses of the Underwriter pursuant to Sections 4 and 7 hereof, (b) the Underwriter to the Company, or (c) of any party hereto to any other party except that the provisions of Section 9 and Section 10 shall at all times be effective and shall survive such termination.

     Section 12. No Advisory or Fiduciary Relationship. The Company acknowledges and agrees that (a) the purchase and sale of the Offered Shares pursuant to this Agreement, including the determination of the public offering price of the Offered Shares and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the Underwriter, on the other hand, (b) in connection with the offering contemplated hereby and the process leading to such transaction the Underwriter is and has been acting solely as a principal and is not the agent or fiduciary of the Company, or its stockholders, creditors, employees or any other party, (c) the Underwriter has not assumed or will not assume an advisory or fiduciary responsibility in favor of the Company with respect to the offering contemplated hereby or the process leading thereto (irrespective of whether the Underwriter has advised or is currently advising the Company on other matters) and the Underwriter has no obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement, (d) the Underwriter and its affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company, and (e) the Underwriter has not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

     Section 13. Representations and Indemnities to Survive Delivery. The respective indemnities, agreements, representations, warranties and other statements of the Company, of its officers and of the Underwriter set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation made by or on behalf of the Underwriter or the Company or any of

its partners, officers or directors or any controlling person, as the case may be, and, anything herein to the contrary notwithstanding, will survive delivery of and payment for the Offered Shares sold hereunder and any termination of this Agreement.

     Section 14. Notices. All communications hereunder shall be in writing and shall be mailed, hand delivered or telecopied and confirmed to the parties hereto as follows:

     If to the Underwriter:

Jefferies & Company, Inc.
520 Madison Avenue
New York, New York 10022
Facsimile: (212)  ###-###-####
Attention: General Counsel

     with a copy to:

Vinson & Elkins L.L.P.
2300 First City Tower
1001 Fannin Street
Houston, Texas 77002-6760
Facsimile: (713)  ###-###-####
Attention: T. Mark Kelly

     If to the Company:

Parallel Petroleum Corporation
1004 N. Big Spring, Suite 400
Midland, Texas 79701
Facsimile: (432)  ###-###-####
Attention: Larry C. Oldham

     with a copy to:

Lynch, Chappell & Alsup
The Summit, Suite 700
300 North Marienfeld
Midland, Texas 79701
Facsimile: (432)  ###-###-####
Attention: Thomas W. Ortloff

     Any party hereto may change the address for receipt of communications by giving written notice to the others.

     Section 15. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto and to the benefit of the employees, officers and directors and controlling persons referred to in Section 9 and Section 10, and in each case their respective successors, and no other person will have any right or obligation hereunder. The term “successors” shall not include any purchaser of the Offered Shares as such from any of the Underwriter merely by reason of such purchase.

     Section 16. Partial Unenforceability. The invalidity or unenforceability of any Section, paragraph or provision of this Agreement shall not affect the validity or enforceability of any other Section, paragraph or provision hereof. If any Section, paragraph or provision of this Agreement is for any reason determined to be invalid or unenforceable, there shall be deemed to be made such minor changes (and only such minor changes) as are necessary to make it valid and enforceable.

     Section 17. Governing Law Provisions. This Agreement shall be governed by and construed in accordance with the internal laws of the State of New York applicable to agreements made and to be performed in such state. Any legal suit, action or proceeding arising out of or based upon this Agreement or the transactions contemplated hereby may be instituted in the federal courts of the United States of America located in the Borough of Manhattan in the City of New York or the courts of the State of New York in each case located in the Borough of Manhattan in the City of New York (collectively, the “Specified Courts”), and each party irrevocably submits to the exclusive jurisdiction (except for proceedings instituted in regard to the enforcement of a judgment of any such court, as to which such jurisdiction is non-exclusive) of such courts in any such suit, action or proceeding. Service of any process, summons, notice or document by mail to such party’s address set forth above shall be effective service of process for any suit, action or other proceeding brought in any such court. The parties irrevocably and unconditionally waive any objection to the laying of venue of any suit, action or other proceeding in the Specified Courts and irrevocably and unconditionally waive and agree not to plead or claim in any such court that any such suit, action or other proceeding brought in any such court has been brought in an inconvenient forum.

     Section 18. General Provisions. This Agreement constitutes the entire agreement of the parties to this Agreement and supersedes all prior written or oral and all contemporaneous oral agreements, understandings and negotiations with respect to the subject matter hereof. This Agreement may be executed in two or more counterparts, each one of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This Agreement may not be amended or modified unless in writing by all of the parties hereto, and no condition herein (express or implied) may be waived unless waived in writing by each party whom the condition is meant to benefit. The Table of Contents and the Section headings herein are for the convenience of the parties only and shall not affect the construction or interpretation of this Agreement.

     Each of the parties hereto acknowledges that it is a sophisticated business person who was adequately represented by counsel during negotiations regarding the provisions hereof, including, without limitation, the indemnification provisions of Section 9 and the contribution provisions of Section 10, and is fully informed regarding said provisions. Each of the parties hereto further acknowledges that the provisions of Sections 9 and 10 hereto fairly allocate the risks in light of the ability of the parties to investigate the Company, its affairs and its business in order to assure that adequate disclosure has been made in the Registration Statement, any preliminary prospectus, the Time of Sale Prospectus, each free writing prospectus and the Prospectus (and any amendments and supplements thereto), as required by the Securities Act and the Exchange Act.

[Signature page follows.]

     If the foregoing is in accordance with your understanding of our agreement, kindly sign and return to the Company the enclosed copies hereof, whereupon this instrument, along with all counterparts hereof, shall become a binding agreement in accordance with its terms.

     The foregoing Underwriting Agreement is hereby confirmed and accepted by the Underwriter in New York, New York as of the date first above written.

JEFFERIES & COMPANY, INC.
By:		/s/ Frank D. Bracken   Name: Frank D. Bracken III
		Title: Managing Director

Signature page to Underwriting Agreement

SCHEDULE A

3,000,000 Common Shares
par value $.01 per share

     Jefferies & Company, Inc. is underwriting 3,000,000 common shares of the Company at an initial public offering price of $18.50 per share.

     We expect delivery of the shares of common stock will be made through the Depository Trust Company in New York on or about December 6, 2007.

Schedule A

SCHEDULE B

None.

Schedule A

EXHIBIT A

FORM OF OPINION OF COMPANY COUNSEL

Such opinions to be rendered by Haynes and Boone, LLP, special counsel for the Company (“HB”), and Lynch, Chappell & Alsup, P.C., counsel for the Company (“LC”), as indicated.

     1. The Company is validly existing as a corporation in good standing under the laws of the State of Delaware. (HB)

     2. The Company is qualified as a foreign corporation for the transaction of business and is in good standing in the State of Texas and each other state set forth on an exhibit to such opinion, and such counsel has no knowledge that the character of the business conducted by the Company or the location of the properties owned, leased or operated by it makes such qualification necessary (except where the failure to so qualify would not, individually or in the aggregate, have a material adverse effect on the condition (financial or other), results of operations, business or prospects of the Company). (HB)

     3. The Company has all corporate power and authority to own or lease its properties and to conduct its business, as described in the Registration Statement and the Prospectus and to execute and deliver, and perform its obligations under, the Agreement. (HB)

     4. The Company’s authorized capital stock consists of                      shares of common stock, par value $0.01 per share, and          shares of preferred stock, par value $.10 per share; the number of issued and outstanding shares of capital stock of the Company is as set forth under the caption “Capitalization” in the Prospectus Supplement (except for subsequent issues or purchases pursuant to employee benefit plans), and all of the issued shares of capital stock of the Company have been duly and validly authorized and issued, are fully paid and nonassessable and conform to the description thereof contained in the Prospectus and Prospectus Supplement. The Offered Shares have been duly authorized and, when issued and delivered in accordance with the terms of the Agreement against payment therefor as set forth in the Agreement, will be validly issued, fully paid and nonassessable. (LC)

     5. The issuance of the Offered Shares is not subject to the preemptive or other similar rights of any securityholder of the Company pursuant to the Delaware General Corporation Law, the certificate of incorporation and by-laws of the Company or any material agreement, contract, indenture, mortgage, loan agreement, note, lease or other agreement or instrument that is described or referred to in the Registration Statement or the Prospectus or filed or incorporated by reference as an exhibit to the Registration Statement or the Company’s Annual Report on Form 10-K for the year ended December 31, 2006, or referenced as a material agreement or filed as an exhibit in reports of the Company filed under the Exchange Act after December 31, 2006 (“Material Agreements”). (LC)

     6. The Agreement has been duly authorized, executed and delivered by the Company. (HB)

     7. The Company is not in violation of its certificate of incorporation, bylaws or other organizational document. (LC)

     8. Neither the offer, sale or delivery of the Offered Shares by the Company, the execution, delivery or performance of the Agreement by the Company (including the use of the proceeds from the sale of the Offered Shares as described in the Prospectus under the caption “Use of Proceeds”) nor compliance by the Company with its obligations under the Agreement constitutes or will constitute,

whether with or without the giving of notice or lapse of time or both, a breach of, or default or Repayment Event (as defined in Section 1(a)(o) of the Agreement) under or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company pursuant to any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or any other agreement or instrument to which the Company is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company is subject, that constitutes a Material Agreement (except for such breaches or defaults or liens, charges or encumbrances that would not result in a Material Adverse Change), nor will any such action result in any violation of (a) the provisions of the charter or bylaws of the Company, (b) any Applicable Laws (as defined in such counsel’s opinion) (assuming compliance with all applicable state securities and blue sky laws) or (c) any judgment, order, writ or decree of any court, governmental agency or arbitrator that is known to such counsel to be applicable to the Company or any of its properties, which in the case of clause (b) and (c) would not cause a Material Adverse Change. (LC)

     9. The Registration Statement and the Prospectus, and each amendment or supplement to the Registration Statement or Prospectus as of their respective effective or issue dates, complied in all respects with the requirements of the Securities Act and the Securities Act Regulations (except that in each case, we express no opinion as to the financial statements, schedules and other financial data included therein or excluded therefrom, or the exhibits thereto). (HB)

     10. Each of the documents incorporated by reference into the Registration Statement filed prior to the date hereof complied in all material respects with the requirements of the Exchange Act and the Exchange Act Regulations (except that in each case, we express no opinion as to the financial statements, schedules and other financial data included therein or excluded therefrom, or the exhibits to any of such documents). (LC)

     11. To such counsel’s knowledge, no stop order suspending the effectiveness of the Registration Statement has been issued, and to such counsel’s knowledge no proceedings for that purpose have been instituted or are pending or threatened by the SEC. The Prospectus has been filed pursuant to Rule 424(b) of the Securities Act Regulations in the manner and within the time period required by the Rule. (HB)

     12. The statements in the Registration Statement and the Prospectus under the caption “Description of Capital Stock,” and in the Registration Statement under Item 15, insofar as they constitute descriptions of contracts, agreements or other legal documents, or refer to statements of law or legal conclusions, fairly summarize the matter referred to therein, subject to the qualifications and assumptions stated therein. (LC)

     13. No Governmental Approval (as defined in such counsel’s opinion), which has not been obtained or taken and is not in full force and effect, is required as a condition to the execution and delivery by the Company of the Agreement, or the performance by the Company of its obligations under the Agreement. (HB)

     14. The Company is not an “investment company” or an entity “controlled” by an “investment company,” as such terms are defined in the 1940 Act. (HB)

     In addition, such counsel shall state that they have participated in conferences with officers and other representatives of the Company and counsel for and other representatives of the Underwriter at which the contents of the Registration Statement and the Prospectus and related matters were discussed and, although such counsel have not independently verified and are not passing upon, and do not assume any responsibility for the accuracy, completeness or fairness of the statements contained in the

Registration Statement and the Prospectus (except and to the extent set forth in paragraph 12 above), on the basis of the foregoing, no facts have come to such counsel’s attention that have lead them to believe that (i) at the time the Registration Statement became effective, the Registration Statement or the Prospectus included therein contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein not misleading or (2) the Time of Sale Prospectus as of the date of this Agreement or as amended or supplemented, if applicable, as of the Closing Date contained or contains any untrue statement of a material fact or omitted or omits to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, or (3) if different from the Time of Sale Prospectus, the Prospectus as of its date or as amended or supplemented, if applicable, as of the Closing Date contained or contains any untrue statement of a material fact or omitted or omits to state a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; it being understood that such counsel expresses no statement or belief with respect to (a) the financial statements and related schedules included therein, including the notes and the auditor’s report thereon, (b) the other information and data of a financial or accounting nature and oil and gas reserve evaluation data and related data included in the Registration Statement or the Prospectus and (c) the exhibits to the Registration Statement.

EXHIBIT B

December 3, 2007

Jefferies & Company, Inc.
909 Fannin, Suite 3100
Houston, Texas 77010

     Re:      Proposed Public Offering by Parallel Petroleum Corporation

Dear Sirs:

     The undersigned, an executive officer and/or, director of Parallel Petroleum Corporation, a Delaware corporation (the “Company”), understands that Jefferies & Company, Inc., (the “Underwriter”) proposes to enter into an Underwriting Agreement (the “Underwriting Agreement”) with the Company providing for the public offering of shares (the “Shares”) of the Company’s common stock, par value $.01 per share (the “Common Stock”). In recognition of the benefit that such an offering will confer upon the undersigned as an executive officer and/or director of the Company, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the undersigned agrees with the Underwriter that, during a period commencing on the date of the Underwriting Agreement and ending on the 60th day after the date of the Underwriting Agreement (the Lock Up Period”), the undersigned will not (and will cause any spouse or immediate family member of the spouse or the undersigned living in the undersigned’s household not to), without the prior written consent of the Underwriter, directly or indirectly, (i) offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant for the sale of, or otherwise dispose of or transfer (or enter into any transaction or device that is designed to, or could be expected to, result in the disposition by any person at any time in the future) any shares of the Company’s Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, whether now owned or hereafter acquired by the undersigned or with respect to which the undersigned has or hereafter acquires the power of disposition, or file any registration statement under the Securities Act of 1933, as amended, with respect to any of the foregoing or (ii) enter into any swap or any other agreement or any transaction that transfers, in whole or in part, directly or indirectly, the economic consequence of ownership of the Common Stock or any securities convertible into or exchangeable or exercisable for Common Stock, whether any such swap or transaction is to be settled by delivery of Common Stock or other securities, in cash or otherwise; provided, that if (A) during the last 17 days of the Lock-up Period, the Company issues an earnings release or material news or a material event relating to the Company occurs, or (B) prior to the expiration of the Lock-up Period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 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 the issuance of the earnings release or the occurrence of the material news or material event, as applicable, unless Jefferies & Company, Inc. waives, in writing, such extension, except that such extension will not apply if, within three business days prior to the 15th calendar day before the last day of the Lock-up Period, the Company delivers a certificate, signed by the Chief Financial Officer or Chief Executive Officer of the Company, certifying on behalf of the Company that (1) the Shares are “actively traded securities” (as defined in Regulation M), (2) the Company meets the applicable requirements of paragraph (a)(1) of Rule 139 under the Securities Act in the manner contemplated by NASD Conduct Rule 2711(f)(4), and (3) the provisions of NASD Conduct Rule 2711(f)(4) are not applicable to any research reports relating to the Company published or distributed by the Underwriter during the 15 days before or after the last day of the Lock-up Period (before giving effect to such extension); provided, further, that the foregoing restrictions in clauses (i) and (ii) shall not apply to:

     (I) the transfer of any or all of the Shares owned by the undersigned, either during his lifetime or on death, by gift, will or intestate succession to the immediate family of the undersigned or to a trust the beneficiaries of which are exclusively the undersigned and/or a member or members of his immediate family; provided, however, that in any such case, it shall be a condition to such transfer that the transferee executes and delivers to Jefferies & Company, Inc. an agreement stating that the transferee is receiving and holding the Shares subject to the provisions of this letter agreement, and there shall be no further transfer of such Shares, except in accordance with this letter agreement;

     (II) any shares of Common Stock issued by the Company upon the exercise of an option or warrant or the conversion of a security outstanding on the date hereof and referred to in the Prospectus;

     (III) any issuance of shares of Common Stock, or granting of options to purchase Common Stock, pursuant to existing employee benefit plans of the Company referred to in the Prospectus;

     (IV) any issuance of shares of Common Stock by the Company, or options to purchase Common Stock, pursuant to any non-employee director stock plan or dividend reinvestment plan described in the Prospectus; or

     (V) any renewal and extension of security interests in shares of Common Stock granted by the undersigned prior to the date of this Agreement.

     The undersigned hereby acknowledges and agrees that written notice of any extension of the Lock-up Period pursuant to the preceding sentence will be delivered by Jefferies & Company, Inc. to the Company and that any such notice properly delivered will be deemed to have been given to, and received by, the undersigned.

     In furtherance of the foregoing, the Company and its transfer agent are hereby authorized to decline to make any transfer of securities if such transfer would constitute a violation or breach of this Lock-Up Letter Agreement.

     The undersigned understands that the Company and the Underwriter will proceed with the public offering of the Shares in reliance on this Lock-Up Letter Agreement.

     The undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Lock-Up Letter Agreement and that, upon request, the undersigned will execute any additional documents reasonably necessary in connection with the enforcement hereof. Any obligations of the undersigned shall be binding upon the heirs, personal representatives, successors and assigns of the undersigned.

		Very truly yours,