UNDERWRITING AGREEMENT

Exhibit 1.1

Execution Version

10,000,000 Shares

Mariner Energy, Inc.

Common Stock

UNDERWRITING AGREEMENT

June 4, 2009

Credit Suisse Securities (USA) LLC
J.P. Morgan Securities Inc.
Merrill Lynch, Pierce, Fenner & Smith Incorporated,
As Representatives of the Several Underwriters,
c/o Credit Suisse Securities (USA) LLC,
      Eleven Madison Avenue
      New York, N.Y. 10010-3629

Dear Sirs:

     1.  Introductory . Mariner Energy, Inc., a Delaware corporation (“ Company ”), agrees with the several Underwriters named in Schedule A hereto (“ Underwriters ”) to issue and sell to the several Underwriters 10,000,000 shares (“ Firm Securities ”) of its common stock, $0.0001 par value (the “ Securities ”), and also agrees to issue and sell to the Underwriters, at the option of the Underwriters, an aggregate of not more than 1,500,000 additional shares (“ Optional Securities ”) of its Securities as set forth below. The Firm Securities and the Optional Securities are herein collectively called the “ Offered Securities ”.

     2.  Representations and Warranties of the Company . The Company represents and warrants to, and agrees with, the several Underwriters that:

     (a) Filing and Effectiveness of Registration Statement; Certain Defined Terms . The Company has filed with the Commission a registration statement on Form S-3ASR (No. 333-159682), including a related prospectus or prospectuses, covering the registration of the Offered Securities under the Act, which has become effective. “ Registration Statement ” at any particular time means such registration statement in the form then filed with the Commission, including any amendment thereto, all exhibits thereto (but not including the Statement of Eligibility of Trustee on Form T-1), any document incorporated by reference therein and all 430B Information and all 430C Information with respect to such registration statement, that in any case has not been superseded or modified. “ Registration Statement ” without reference to a time means the Registration Statement as of the Effective Time. For purposes of this definition, 430B Information shall be considered to be included in the Registration Statement as of the time specified in Rule 430B.

     For purposes of this underwriting agreement (this “ Agreement ”):

     “ 430B Information ” means information included in a prospectus then deemed to be a part of the Registration Statement pursuant to Rule 430B(e) or retroactively deemed to be a part of the Registration Statement pursuant to Rule 430B(f).

     “ 430C Information ” means information included in a prospectus then deemed to be a part of the Registration Statement pursuant to Rule 430C.

     “ Act ” means the Securities Act of 1933, as amended.

     “ Applicable Time ” means 11:30 pm (Eastern time) on the date of this Agreement.

     “ Closing Date ” has the meaning defined in Section 3 hereof.

     “ Commission ” means the Securities and Exchange Commission.

     “ Effective Time ” of the Registration Statement relating to the Offered Securities means the time of the first contract of sale for the Offered Securities.

     “ Exchange Act ” means the Securities Exchange Act of 1934, as amended.

     “ Final Prospectus ” means the Statutory Prospectus that discloses the public offering price, other 430B Information and other final terms of the Offered Securities and otherwise satisfies Section 10(a) of the Act.

     “ General Use Issuer Free Writing Prospectus ” means any Issuer Free Writing Prospectus that is intended for general distribution to prospective investors, as evidenced by its being so specified in Schedule B to this Agreement.

     “ Issuer Free Writing Prospectus ” means any “issuer free writing prospectus,” as defined in Rule 433, relating to the Offered Securities in the form filed or required to be filed with the Commission or, if not required to be filed, in the form retained in the Company’s records pursuant to Rule 433(g).

     “ Limited Use Issuer Free Writing Prospectus ” means any Issuer Free Writing Prospectus that is not a General Use Issuer Free Writing Prospectus.

     “ Rules and Regulations ” means the rules and regulations of the Commission.

     “ Securities Laws ” means, collectively, the Sarbanes-Oxley Act of 2002 (“ Sarbanes-Oxley ”), the Act, the Exchange Act, the Rules and Regulations, the auditing principles, rules, standards and practices applicable to auditors of “issuers” (as defined in Sarbanes-Oxley) promulgated or approved by the Public Company Accounting Oversight Board and, as applicable, the rules of the New York Stock Exchange and the NASDAQ Stock Market (“ Exchange Rules ”).

     “ Statutory Prospectus ” with reference to any particular time means the prospectus relating to the Offered Securities that is included in the Registration Statement immediately prior to that time, including all 430B Information and all 430C Information with respect to the Registration Statement. For purposes of the foregoing definition, 430B Information shall be considered to be included in the Statutory Prospectus only as of the actual time that the form of prospectus (including a prospectus supplement) is filed with the Commission pursuant to Rule 424(b) and not retroactively.

     Unless otherwise specified, a reference to a “rule” is to the indicated rule under the Act.

     (b) Compliance with Securities Act Requirements . (i) (A) At the time the Registration Statement initially became effective, (B) at the time of each amendment thereto for the purposes of complying with Section 10(a)(3) of the Act (whether by post-effective amendment, incorporated report or form of prospectus), (C) at the Effective Time relating to the Offered Securities and (D) on the Closing Date, the Registration Statement conformed and will conform in all material respects to the requirements of the Act and the Rules and Regulations thereunder and did not and will not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading; and (ii) (A) on its date, (B) at the time of filing the Final Prospectus pursuant to Rule 424(b) and (C) on the Closing Date, the Final Prospectus will conform in all material respects to the requirements of the Act and the Rules and Regulations, and will not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from any such document based upon written information furnished to the Company by any Underwriter through the Representatives

specifically for use therein, it being understood and agreed that the only such information is that described as such in Section 8(b) hereof.

     (c) Automatic Shelf Registration Statement . (i) Well-Known Seasoned Issuer Status . (A) At the time of initial filing of the Registration Statement, (B) at the time of the most recent amendment thereto for the purposes of complying with Section 10(a)(3) of the Act (whether such amendment was by post-effective amendment, incorporated report filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), and (C) at the time the Company or any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c)) made any offer relating to the Offered Securities in reliance on the exemption of Rule 163, the Company was a “well known seasoned issuer” as defined in Rule 405, including not having been an “ineligible issuer” as defined in Rule 405.

     (d) Ineligible Issuer Status . (i) At the earliest time after the filing of the Registration Statement that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2)) of the Offered Securities and (ii) at the date of this Agreement, the Company was not and is not an “ineligible issuer,” as defined in Rule 405, including (x) the Company or any other subsidiary in the preceding three years not having been convicted of a felony or misdemeanor or having been made the subject of a judicial or administrative decree or order as described in Rule 405 and (y) the Company in the preceding three years not having been the subject of a bankruptcy petition or insolvency or similar proceeding, not having had a registration statement be the subject of a proceeding under Section 8 of the Act and not being the subject of a proceeding under Section 8A of the Act in connection with the offering of the Securities, all as described in Rule 405.

     (e) General Disclosure Package . As of the Applicable Time, neither (i) any General Use Issuer Free Writing Prospectus(es) issued at or prior to the Applicable Time, the preliminary prospectus supplement relating to the Offered Securities, dated June 2, 2009, including the base prospectus, dated June 2, 2009 (which is the most recent Statutory Prospectus distributed to investors generally) (the “ Preliminary Prospectus ”), and the other information, if any, stated in Schedule B to this Agreement to be included in the General Disclosure Package, all considered together (collectively, the “ General Disclosure Package ”), nor (ii) any individual Limited Use Issuer Free Writing Prospectus, when considered together with the General Disclosure Package, included any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding sentence does not apply to statements in or omissions from any preliminary prospectus supplement referenced above, any Statutory Prospectus or any Issuer Free Writing Prospectus in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 8(b) hereof.

     (f) Issuer Free Writing Prospectuses . Each Issuer 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 Securities or until any earlier date that the Company notified or notifies the Representatives as described in the next sentence, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information then contained in the Registration Statement. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information then contained in the Registration Statement or as a result of which such Issuer Free Writing Prospectus, if republished immediately following such event or development, 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 under which they were made, not misleading, (i) the Company has promptly notified or will promptly notify the Representatives and (ii) the Company has promptly amended or will promptly amend or supplement such Issuer Free Writing Prospectus to eliminate or correct such conflict, untrue statement or omission. The foregoing two sentences do not apply to statements in or omissions from any Issuer Free Writing Prospectus in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by any Underwriter consists of the information described as such in Section 8(b) hereof.

     (g) Good Standing of the Company . The Company has been duly incorporated and is existing and in good standing under the laws of the State of Delaware, with corporate power and authority to own its properties and conduct its business as described in the General Disclosure Package; and the Company is duly qualified to do business as a foreign corporation in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its

business requires such qualification (except such failures to qualify that would not reasonably be expected to constitute, either individually or in the aggregate, a Material Adverse Effect (as defined below)).

     (h) Subsidiaries . Each subsidiary of the Company has been duly incorporated or formed, as the case may be, and is existing and in good standing under the laws of the jurisdiction of its incorporation or formation, with power and authority (corporate and other) to own its properties and conduct its business as described in the General Disclosure Package; and each subsidiary is duly qualified to do business as a foreign corporation or limited liability company, as applicable, in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification (except such failures to qualify that would not reasonably be expected to constitute, either individually or in the aggregate, a Material Adverse Effect); all of the issued and outstanding shares and limited liability company interests, as applicable, of each subsidiary have been duly authorized and validly issued in accordance with the organizational documents of such subsidiary and is fully paid (to the extent required under such subsidiary’s organization documents) and nonassessable, except as such non-assessability may be affected by Section 18-303, 18-607 and 18-804 of the Delaware Limited Liability Company Act; and the shares and limited liability company interests owned by the Company, directly or through subsidiaries, are owned free from liens, encumbrances and defects other than (i) as described in the Registration Statement, the General Disclosure Package and the Final Prospectus and (ii) those created by or arising in connection with the Amended and Restated Credit Agreement, dated as of March 2, 2006, as amended, among the Company and Mariner Energy Resources, Inc., as borrowers, the lenders party thereto from time to time and Union Bank of California, N.A, as administrative agent and issuing lender.

     (i) Offered Securities . The outstanding shares of capital stock of the Company as of the date of this Agreement have been, and on each Closing Date will be, duly authorized and validly issued in accordance with the organizational documents of the Company and are fully paid and nonassessable; when the Offered Securities have been delivered and paid for in accordance with this Agreement on each Closing Date, such Offered Securities will have been duly authorized, validly issued, fully paid and nonassessable, will conform in all material respects to the information in the General Disclosure Package and to the description of such Offered Securities contained in the Final Prospectus; the stockholders of the Company have no preemptive rights with respect to the Securities; and none of the outstanding shares of capital stock of the Company has been issued in violation of any preemptive or similar rights of any security.

     (j) No Finder’s Fee . There are no contracts, agreements or understandings between the Company and any person (other than this Agreement) that would give rise to a valid claim against any of them or any Underwriter for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Offered Securities.

     (k) Registration Rights . Except as disclosed in the General Disclosure Package and except for those agreements listed on Schedule E to this Agreement, 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 Act with respect to any securities of the Company owned or to be owned by such person or to require the Company to include such securities in the securities registered pursuant to a Registration Statement or in any securities being registered pursuant to any other registration statement filed by the Company under the Act (collectively, “ registration rights ”), and any person to whom the Company has granted registration rights has agreed not to or is not entitled to exercise such rights until after the expiration of the Lock-Up Period referred to in Section 5 hereof.

     (l) Listing . The Offered Securities have been approved for listing on The New York Stock Exchange, subject to notice of issuance.

     (m) Absence of Further Requirements . No consent, approval, authorization or order of, or filing or registration with, any person (including any governmental agency or body or any court) is required for the consummation of the transactions contemplated by this Agreement in connection with the offering, issuance and sale of the Offered Securities by the Company, except such as have been obtained, or made and such as may be required under state securities laws.

     (n) Title to Property . The Company or its subsidiaries have legal, valid and defensible title to substantially all the interests in oil and gas properties underlying the Company’s estimates of its net proved reserves contained in the General Disclosure Package and to substantially all other real and personal property reflected in the General Disclosure Package as assets owned by them, in each case free and clear of all liens, encumbrances and defects, except such as are described in the General Disclosure Package or as would not be reasonably expected to have a Material Adverse Effect; and any other real property and buildings held under lease by the Company or its subsidiaries are held by them under valid, subsisting and enforceable leases, with such exceptions as are not material and do not materially interfere with the use made and proposed to be made of such property and buildings by the Company or its subsidiaries; and the care taken by the Company and its subsidiaries with respect to acquiring or otherwise procuring such leases, options to lease, drilling rights and concessions or other property interests was generally consistent with standard industry practices in the areas in which the Company operates for acquiring or procuring leases and interests therein to explore, develop or produce hydrocarbons.

     (o) Absence of Defaults and Conflicts Resulting from Transaction . The execution, delivery and performance of this Agreement, the issuance and sale of the Offered Securities and compliance with the terms and provisions hereof (i) will not result in a breach or violation of any of the terms and provisions of, or constitute a default or a Debt Repayment Triggering Event (as defined below) under any indenture, mortgage, deed of trust, loan agreement, lease or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries is bound or to which any of the property or assets of the Company or any of its subsidiaries is subject, (ii) will not result in any violation of the provisions of the charter or by-laws, limited liability company agreement, partnership agreement or similar organizational document of the Company or any of its subsidiaries or (iii) will not violate any statute or any order, rule or regulation of any court or governmental agency or body having jurisdiction over the Company or any of its subsidiaries or any of their properties or assets; except, in the case of clauses (i) and (iii) above, as would not reasonably be expected to have a Material Adverse Effect; a “ Debt Repayment Triggering Event ” means any event or condition that gives, or with the giving of notice or lapse of time would give, 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 or any of its subsidiaries.

     (p) Absence of Existing Defaults and Conflicts . Neither the Company nor any of its subsidiaries is (i) in violation of its respective charter, by-laws, certificate of formation or limited liability company agreement, (ii) in default (or with the giving of notice or lapse of time would be in default) under any existing obligation, agreement, covenant or condition contained in any indenture, loan agreement, mortgage, lease or other agreement or instrument to which any of them is a party or by which any of them is bound or to which any of the properties of any of them is subject or (iii) in violation of any law, ordinance, governmental rule, regulation or court decree to which it or its property or assets may be subject or has failed to obtain or maintain any material license, permit, certificate, franchise or other governmental authorization or permit necessary to the ownership of its property or to the conduct of its business except, in the case of clauses (ii) and (iii), as would not, individually or in the aggregate, result in a material adverse effect on the condition (financial or otherwise), stockholders’ equity, results of operations, business or properties of the Company and its subsidiaries taken as a whole (“ Material Adverse Effect ”).

     (q) No Restrictions on Subsidiaries . Except as disclosed in the Registration Statement or the General Disclosure Package, no subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such subsidiary’s capital stock, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary’s properties or assets to the Company or any other subsidiary of the Company.

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

     (s) Absence of Labor Dispute . No labor dispute with the employees of the Company or any of its subsidiaries exists or, to the knowledge of the Company, is imminent that in either case would reasonably be expected to have a Material Adverse Effect.

     (t) Environmental Laws . Except as disclosed in the General Disclosure Package, (i)(A) neither the Company nor any of its subsidiaries has received any notice that has not been resolved alleging that it is in violation of any federal, state, local or foreign statute, law, rule, regulation, ordinance, code, policy or any judicial or administrative interpretation thereof, including any judicial or administrative order, consent, decree or judgment, pertaining to pollution or protection of human health, the environment (including, without limitation, ambient air, surface water, groundwater, land surface or subsurface strata) or wildlife, including, without limitation, laws and regulations pertaining to the release or threatened release of chemicals, pollutants, contaminants, wastes, toxic substances, hazardous substances, petroleum or petroleum products, asbestos-containing materials or mold (collectively, “ Hazardous Materials ”) or to the manufacture, processing, distribution, use, treatment, storage, disposal, transport or handling of Hazardous Materials (collectively, “ Environmental Laws ”), (ii) the Company and its subsidiaries have all permits, authorizations and approvals required under any applicable Environmental Laws and are each in compliance with their requirements, (iii) there are no pending or, to the knowledge of the Company, threatened administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings under any Environmental Law against the Company, or any of its subsidiaries, and (iv) to the knowledge of the Company, there are no events or circumstances that would 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 or any of its subsidiaries pertaining to Hazardous Materials or under any Environmental Laws.

     (u) Accurate Disclosure . The statements in the Statutory Prospectus under the heading “Description of Capital Stock,” insofar as they purport to constitute a summary of the terms of the Securities, and the statements in the Preliminary Prospectus and the Final Prospectus under the heading “Certain U.S. Federal Income and Estate Tax Considerations,” insofar as they purport to describe the provisions of the laws and documents referred to therein, are accurate in all material respects.

     (v) Absence of Manipulation . The Company has not taken, directly or indirectly, any action that is designed to or that has constituted or that would reasonably be expected to cause or result in the stabilization or manipulation of the price of any security of the Company to facilitate the sale or resale of the Offered Securities.

     (w) Internal Controls and Compliance with the Sarbanes-Oxley Act . Except as set forth in the General Disclosure Package, the Company, its subsidiaries and the Company’s Board of Directors (the “ Board ”) are in compliance with Sarbanes-Oxley and all applicable Exchange Rules. The Company maintains a system of internal controls, including, but not limited to, disclosure controls and procedures, internal controls over accounting matters and financial reporting, an internal audit function and legal and regulatory compliance controls (collectively,

“ Internal Controls ”) that comply with the Securities Laws and are sufficient to provide reasonable assurances that (i) transactions are executed in accordance with management’s general or specific authorizations, (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with U.S. General Accepted Accounting Principles 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 the existing assets at reasonable intervals and appropriate action is taken with respect to any differences. The Internal Controls are, or upon consummation of the offering of the Offered Securities will be, overseen by the Audit Committee (the “ Audit Committee ”) of the Board in accordance with Exchange Rules. The Company has not publicly disclosed or reported to the Audit Committee or the Board a material weakness, change in Internal Controls or fraud involving management or other employees who have a significant role in Internal Controls, any violation of, or failure to comply with, the Securities Laws, or any matter which, if determined adversely, would reasonably be expected to have a Material Adverse Effect. Within the next 90 days the Company does not reasonably expect to publicly disclose or report to the Audit Committee or the Board a material weakness, change in Internal Controls or fraud involving management or other employees who have a significant role in Internal Controls, any violation of, or failure to comply with, the Securities Laws, or any matter which, if determined adversely, would reasonably be expected to have a Material Adverse Effect. The Company is not aware of any significant deficiency that it reasonably expects to publicly disclose or report to the Audit Committee of the Board within the next 90 days.

     (x) Litigation . Except as disclosed in the General Disclosure Package, there are no legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or of which any property or assets of the Company or any of its subsidiaries is the subject that, if determined adversely to the Company or any of its subsidiaries, is reasonably likely to have a Material Adverse Effect, and to the knowledge of the Company, no such proceedings are threatened or contemplated by governmental authorities or threatened by others.

     (y) Financial Statements . The historical financial statements (including the related notes and schedules) included or incorporated by reference in the Registration Statement and the General Disclosure Package present fairly in all material respects the financial position of the Company and its consolidated subsidiaries as of the dates shown and their results of operations and cash flows for the periods shown, and such financial statements have been prepared in conformity with the generally accepted accounting principles in the United States applied on a consistent basis, except in each case as set forth or contemplated in the Registration Statement and the General Disclosure Package.

     (z) No Material Adverse Change in Business . Except as disclosed in the General Disclosure Package, since the end of the period covered by the latest audited financial statements included in the General Disclosure Package (i) there has been no change, nor any development or event involving a prospective change, in the condition (financial or otherwise), stockholders’ equity, results of operations, business or properties of the Company and its subsidiaries, taken as a whole, that is material and adverse, (ii) except as disclosed in or contemplated by the General Disclosure Package, there has been no dividend or distribution of any kind declared, paid or made by the Company or any of its subsidiaries on any class of their capital stock and (iii) except as disclosed in or contemplated by the General Disclosure Package, there has been no material adverse change in the capital stock, short-term indebtedness, long-term indebtedness, net current assets or net assets of the Company and any of its subsidiaries.

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

     (bb) Ratings . No “nationally recognized statistical rating organization” as such term is defined for purposes of Rule 436(g)(2) (i) has imposed (or has informed the Company that it is considering imposing) any condition (financial or otherwise) on the Company’s retaining any rating assigned to the Company or any securities of the Company or (ii) has indicated to the Company that it is considering any of the actions described in Section 7(c)(ii) hereof.

     (cc) Independent Accountants . Deloitte & Touche LLP, who have certified certain financial statements of the Company, whose report is incorporated by reference into the General Disclosure Package, were independent registered public accountants as required by the Act and rules and regulations promulgated thereunder and the rules and regulations promulgated by the Public Company Accounting Oversight Board during the periods covered by the financial statements on which they reported contained in the General Disclosure Package.

     (dd) Independent Reserve Engineers . Ryder Scott Company, L.P. (“ Ryder Scott ”), whose reports are referenced in the General Disclosure Package (collectively, the “ Reserve Reports ”) was, as of the date of each of the Reserve Reports, and is, as of the date hereof, an independent reserve engineer with respect to the Company. No information has come to the attention of the Company or, to the Company’s knowledge, to Ryder Scott, that would reasonably be expected to cause Ryder Scott to withdraw its Reserve Reports.

     (ee) Reserve Reports . The oil and gas reserve estimates of the Company and its subsidiaries as of December 31, 2008, 2007 and 2006 contained in the General Disclosure Package are based on estimates made in reserve reports prepared by an independent petroleum engineering firm as set forth in the General Disclosure Package, such reserve estimates fairly reflect the oil and gas reserves of the Company and its subsidiaries at the dates indicated in the General Disclosure Package and are in accordance with Commission guidelines applied on a consistent basis throughout the periods involved. The information underlying the estimates described above that was supplied to Ryder Scott for the purposes of preparing the reserve report and audit referred to above, including production and costs of operation, was true and correct in all material respects on the dates such estimates were made, and such information was supplied and was prepared in accordance with customary industry practices; other than normal production of the reserves, product price fluctuations, fluctuations of demand for such products, hurricanes, loop currents and other adverse weather conditions, unavailability or increased costs of rigs, equipment, supplies or personnel, the timing of third party operations and other factors disclosed in the General Disclosure Package, the Company is not aware of any facts or circumstances that would result in a material adverse change in the aggregate net reserves, or the present value of the future net cash flows therefrom as described in the General Disclosure Package and as reflected in the reserve reports; the estimates of such reserves and present value as described in the General Disclosure Package and reflected in the reserve reports referenced therein have been prepared in a manner that complies with the applicable requirements of the rules under the Act with respect to proved reserves.

     (ff) Taxes . The Company and its subsidiaries have filed all federal, state and local tax returns that are required to be filed through the date hereof or have requested extensions thereof (except in any case in which the failure so to file would not reasonably be expected to have a Material Adverse Effect); and, except as set forth in the General Disclosure Package, the Company and its subsidiaries have paid all taxes (including any assessments, fines or penalties) required to be paid by them, except for any such taxes, assessments, fines or penalties currently being contested in good faith or as would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

     (gg) Insurance . The Company and each of its subsidiaries carry, or are covered by, insurance in such amounts and covering such risks as is adequate for the conduct of their respective businesses and the value of their respective properties and as is customary for companies engaged in similar businesses in similar industries.

     (hh) ERISA . The Company is in compliance in all material respects with all presently applicable provisions of the Employee Retirement Income Security Act of 1974, as amended, including the regulations and published interpretations thereunder (“ ERISA ”); no “reportable event” (as defined in ERISA) has occurred with respect to any “pension plan” (as defined in ERISA) for which the Company or any subsidiary would have any liability; neither the Company nor any subsidiary has incurred or expects to incur liability under (i) Title IV of ERISA with respect to termination of, or withdrawal from, any “pension plan” or (ii) Sections 412 or 4971 of the Internal Revenue Code of 1986, as amended, including the regulations and published interpretations thereunder (the “ Code ”); and each “pension plan” for which the Company or any subsidiary would have any liability that is intended to be qualified under Section 401(a) of the Code is so qualified in all material respects and nothing has occurred, whether by action or by failure to act, which would cause the loss of such qualification.

     (ii) Additional Obligations . Since the latest date as of which information is given in the General Disclosure Package through the date hereof, and except as may otherwise be disclosed in the General Disclosure Package, neither the Company nor any subsidiary has (i) issued or granted any securities (other than issuances of restricted stock or options under the Company’s equity plans), (ii) incurred any liability or obligation, direct or contingent, other than liabilities and obligations that were incurred in the ordinary course of business, (iii) entered into any transaction not in the ordinary course of business or (iv) declared or paid any dividend on its capital stock.

     (jj) Margin Rules. None of the transactions contemplated by this Agreement (including, without limitation, the use of the proceeds from the sale of the Offered Securities), will violate or result in a violation of Section 7 of the Exchange Act, or any regulation promulgated thereunder, including, without limitation, Regulations T, U and X of the Board of Governors of the Federal Reserve System.

     3.  Purchase, Sale and Delivery of Offered Securities . On the basis of the representations, warranties and agreements and subject to the terms and conditions set forth herein, the Company agrees to sell to the several Underwriters, and each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at a purchase price of $13.8852635 per share, the respective number of shares of Firm Securities set forth opposite the names of the Underwriters in Schedule A hereto.

     The Company will deliver the Firm Securities to, or as instructed by, the Representatives for the accounts of the several Underwriters in a form reasonably acceptable to the Representatives against payment of the aggregate purchase price described in the preceding paragraph by the Underwriters in Federal (same day) funds by wire transfer to an account at a bank acceptable to the Representatives drawn to the order of the Company at the office of Akin Gump Strauss Hauer & Feld LLP, at 10:00 A.M., New York time, on June 10, 2009, or at such other time not later than seven full business days thereafter as the Representatives and the Company determine, such time being herein referred to as the “ First Closing Date ”. For purposes of Rule 15c6-1 under the Exchange Act, the First Closing Date (if later than the otherwise applicable settlement date) shall be the settlement date for payment of funds and delivery of securities for all the Offered Securities sold pursuant to the offering. The Firm Securities so to be delivered or evidence of their issuance will be made available for checking at the above office at least 24 hours prior to the First Closing Date.

     In addition, upon written notice from the Representatives given to the Company from time to time not more than 30 days subsequent to the date of the Final Prospectus, the Underwriters may purchase all or less than all of the Optional Securities at the purchase price per Security to be paid for the Firm Securities. The Company agrees to sell to the Underwriters the number of shares of Optional Securities specified in such notice and the Underwriters agree, severally and not jointly, to purchase such Optional Securities, as applicable. Such Optional Securities shall be purchased for the account of each Underwriter in the same proportion as the number of shares of Firm Securities set forth opposite such Underwriter’s name bears to the number of shares of Firm Securities (subject to adjustment by the Representatives to eliminate fractions), and may be purchased by the Underwriters only for the purpose of covering over-allotments

made in connection with the sale of the Firm Securities. No Optional Securities shall be sold or delivered unless the Firm Securities previously have been, or simultaneously are, sold and delivered. The right to purchase the Optional Securities, or any portion thereof, may be exercised from time to time and to the extent not previously exercised may be surrendered and terminated at any time upon notice by the Representatives to the Company.

     Each time for the delivery of and payment for the Optional Securities, being herein referred to as an “ Optional Closing Date ”, which may be the First Closing Date (the First Closing Date and each Optional Closing Date, if any, being sometimes referred to as a “ Closing Date ”), shall be determined by the Representatives but shall be not later than five full business days after written notice of election to purchase such Optional Securities is given. The Company will deliver the applicable Optional Securities being purchased on each Optional Closing Date to or as instructed by the Representatives for the accounts of the several Underwriters in a form reasonably acceptable to the Representatives against payment of the purchase price therefor in Federal (same day) funds by wire transfer to an account at a bank acceptable to the Representatives drawn to the order of the Company, at the office of Akin Gump Strauss Hauer & Feld LLP. The Optional Securities being purchased on each Optional Closing Date or evidence of their issuance will be made available for checking at the office of Akin Gump Strauss Hauer & Feld LLP at a reasonable time in advance of such Optional Closing Date.

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

     5.  Cer