UNDERWRITING AGREEMENT

EXECUTION VERSION

exhibit 1.1

ConocoPhillips

Debt Securities
fully and unconditionally guaranteed by ConocoPhillips Company

UNDERWRITING AGREEMENT

     1.  Introductory. ConocoPhillips, a Delaware corporation (the “ Company ”), and ConocoPhillips Company, a Delaware corporation and a wholly owned subsidiary of ConocoPhillips (“ CPCo ”), propose that the Company will issue and sell from time to time certain of its unsecured debt securities fully and unconditionally guaranteed by CPCo (the “ Guarantor ”) registered under the registration statement referred to in Section 2(a) (such securities, including the guarantee relating thereto by CPCo (the “ Guarantee ”), being hereinafter called the “ Registered Securities ”). The Registered Securities will be issued under an indenture, dated as of October 9, 2002 (the “ Indenture ”), among the Company, CPCo and The Bank of New York Trust Company, National Association, as trustee (the “ Trustee ”), in one or more series, which series may vary as to interest rates, maturities, redemption provisions, selling prices and other terms, with all such terms for any particular series of the Registered Securities being determined at the time of sale. Particular series of the Registered Securities will be sold pursuant to a Terms Agreement referred to in Section 3, for resale in accordance with terms of offering determined at the time of sale.

     The Registered Securities involved in any such offering are hereinafter referred to as the “ Offered Securities ”. The firm or firms which agree to purchase the Offered Securities are hereinafter referred to as the “ Underwriters ” of such securities, and the representative or representatives of the Underwriters, if any, specified in a Terms Agreement referred to in Section 3 are hereinafter referred to as the “ Representatives ”; provided, however, that if the Terms Agreement does not specify any representative of the Underwriters, the term “Representatives”, as used in this Agreement (other than in Sections 2(b), 2(c), 2(f) and 6 and the second sentence of Section 3), shall mean the Underwriters.

     2.  Representations and Warranties of the Company . The Company, as of the date of each Terms Agreement referred to in Section 3, represents and warrants to, and agrees with, each Underwriter that:

     (a) The Company and CPCo meet the requirements for use of Form S-3 under the Act and have prepared and filed with the Securities and Exchange Commission (the “ Commission ”) an automatic shelf registration statement, as defined in Rule 405, on Form S-3 (No. 333-133363 and 333-133363-03), including a prospectus (hereinafter referred to as the “ Base Prospectus ”), relating to the Registered Securities, which registration statement became effective upon filing. Such registration statement, as amended at the time of any Terms Agreement referred to in Section 3 entered into in connection with a specific offering of the Offered Securities (each such date and time as specified in such Terms Agreement hereinafter referred to as the “ Execution Time ”) and including

any documents incorporated by reference therein, including exhibits (other than any Form T-1) and financial statements and any prospectus supplement relating to the Offered Securities that is filed with the Commission pursuant to Rule 424(b) (“ Rule 424(b) ”) under the Securities Act of 1933 (the “ Act ”) and deemed part of such registration statement pursuant to Rule 430B under the Act, is hereinafter referred to as the “ Registration Statement .” The Base Prospectus, as supplemented as contemplated by Section 3 to reflect the terms of the Offered Securities and the terms of offering thereof, as first filed with the Commission pursuant to and in accordance with Rule 424(b), including all material incorporated by reference therein, is hereinafter referred to as the “ Final Prospectus .” Any preliminary prospectus supplement to the Base Prospectus which describes the Offered Securities and the offering thereof and is used prior to filing of the Final Prospectus, together with the Base Prospectus, is hereinafter referred to as the “ Preliminary Final Prospectus .” “ Free Writing Prospectus ” shall mean a free writing prospectus, as defined in Rule 405 under the Act. “ Issuer Free Writing Prospectus ” shall mean an issuer free writing prospectus, as defined in Rule 433 under the Act. “ Disclosure Package ” shall mean, with respect to any specific offering of the Offered Securities, (i) the Base Prospectus, as amended and supplemented to the Execution Time, (ii) the Preliminary Final Prospectus, if any, used most recently prior to the Execution Time, (iii) the Issuer Free Writing Prospectuses, if any, identified in Schedule B to the Terms Agreement, (iv) the final term sheet prepared and filed pursuant to Section 4(c) hereto, if any, and (v) any other Free Writing Prospectus that the parties hereto shall hereafter expressly agree in writing to treat as part of the Disclosure Package. No document has been or will be prepared or distributed in reliance on Rule 434 under the Act.

     (b) On the effective date of the registration statement relating to the Registered Securities, such registration statement conformed in all respects to the requirements of the Act, the Trust Indenture Act of 1939 (“ Trust Indenture Act ”) and the rules and regulations of the Commission (“ Rules and Regulations ”) and did not include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein not misleading, and at the Execution Time and at the Closing Date, the Registration Statement and the Final Prospectus will conform in all respects to the requirements of the Act, the Trust Indenture Act and the Rules and Regulations, and neither of such documents will 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, except that the foregoing does not apply to statements in or omissions from any of such documents based upon written information furnished to the Company by any Underwriter through the Representatives, if any, specifically for use therein.

     (c) At the Execution Time, the Disclosure Package will not contain any untrue statement of a material fact or omit 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, except that the foregoing does not apply

to statements in or omissions from any of such documents based upon written information furnished to the Company by any Underwriter through the Representatives, if any, specifically for use therein.

     (d) (i) At the time of filing the Registration Statement, (ii) 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 Sections 13 or 15(d) of the Exchange Act or form of prospectus), (iii) 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 in Rule 163, and (iv) at the Execution Time (with such date being used as the determination date for purposes of this clause (iv)), the Company was or is (as the case may be) a “well-known seasoned issuer” as defined in Rule 405. The Company agrees to pay the fees required by the Commission relating to the Offered Securities within the time required by Rule 456(b)(1) without regard to the proviso therein and otherwise in accordance with Rules 456(b) and 457(r).

     (e) (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 any Offered Securities and (ii) as of the Execution Time (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an Ineligible Issuer (as defined in Rule 405), without taking account of any determination by the Commission pursuant to Rule 405 that it is not necessary that the Company be considered an Ineligible Issuer.

     (f) Each Issuer Free Writing Prospectus, if any, and the final term sheet prepared and filed pursuant to Section 4(c) hereto do not include any information that conflicts with the information contained in the Registration Statement, including any document incorporated by reference therein and any prospectus supplement deemed to be a part thereof that has not been superseded or modified, except that the foregoing does not apply to statements in or omissions from any of such documents based upon written information furnished to the Company by any Underwriter through the Representatives, if any, specifically for use therein.

     3.  Purchase and Offering of Offered Securities . The obligation of the Underwriters to purchase the Offered Securities will be evidenced by an agreement or exchange of other written communications (“ Terms Agreement ”) at the time the Company determines to sell the Offered Securities. The Terms Agreement will incorporate by reference the provisions of this Agreement, except as otherwise provided therein, and will specify the firm or firms which will be Underwriters, the names of any Representatives, the principal amount of the Offered Securities to be purchased by each Underwriter, the commission or fee to be paid to the Underwriters and the terms of the Offered Securities not already specified in the Indenture, including, but not limited to, interest rate, maturity, any redemption provisions and any sinking fund requirements. The Terms Agreement will also specify the time and date of delivery and payment (such

time and date, or such other time not later than seven full business days thereafter as the Representatives and the Company agree as the time for payment and delivery, being herein and in the Terms Agreement referred to as the “ Closing Date ”), the place of delivery and payment and any details of the terms of offering that should be reflected in the prospectus supplement relating to the offering of the Offered Securities. For purposes of Rule 15c6-1 under the Securities Exchange Act of 1934, the Closing Date (if later than the otherwise applicable settlement date) shall be the date for payment of funds and delivery of securities for all the Offered Securities sold pursuant to the offering. The obligations of the Underwriters to purchase the Offered Securities will be several and not joint. It is understood that the Underwriters propose to offer the Offered Securities for sale as set forth in the Final Prospectus.

     If the Terms Agreement specifies “Book-Entry Only” settlement or otherwise states that the provisions of this paragraph shall apply, the Company will deliver against payment of the cash purchase price the Offered Securities in the form of one or more permanent global securities in definitive form (the “ Global Securities ”) deposited with the Trustee as custodian for The Depository Trust Company (“ DTC ”) and registered in the name of Cede & Co., as nominee for DTC. Interests in any permanent global securities will be held only in book-entry form through DTC, except in the limited circumstances described in the Final Prospectus. Payment for the Offered Securities shall be made by the Underwriters in Federal (same day) funds by official check or checks or wire transfer to an account previously designated by the Company at a bank acceptable to the Representatives, in each case drawn to the order of the Company at the place of payment specified in the Terms Agreement on the Closing Date, against delivery to the Trustee as custodian for DTC of the Global Securities representing all of the Offered Securities.

     4.  Certain Agreements of the Company . The Company agrees with the several Underwriters that it will furnish to counsel for the Underwriters one signed copy of the registration statement relating to the Registered Securities, including all exhibits, in the form it became effective and of all amendments thereto and that, in connection with each offering of Offered Securities:

     (a) The Company will file the Final Prospectus with the Commission pursuant to and in accordance with Rule 424(b)(2) (or, if applicable and if consented to by the Representatives, subparagraph (5)) not later than the second business day following the execution and delivery of the Terms Agreement.

     (b) During any time when a prospectus relating to the Offered Securities is required to be delivered under the Act in connection with sales by any Underwriter or dealer (including in circumstances where such requirement may be satisfied pursuant to Rule 172), the Company will advise the Representatives promptly of any proposal to amend or supplement the Registration Statement or the Final Prospectus and will afford the Representatives a reasonable opportunity to comment on any such proposed amendment or supplement; and the Company will also advise the Representatives promptly of the filing of any such amendment or supplement and of the institution by the Commission of any stop order

proceedings or any notice from the Commission objecting to its use in respect of the Registration Statement or of any part thereof and will use its best efforts to prevent the issuance of any such stop order and to obtain as soon as possible its lifting, if issued.

     (c) The Company will prepare a final term sheet, containing solely a description of the Offered Securities, in a form approved by the Representatives, and will file such term sheet pursuant to Rule 433(d) under the Act within the time required by such Rule.

     (d) If there occurs an event or development as a result of which the Disclosure Package would include an untrue statement of a material fact or would omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances then prevailing, not misleading, the Company will promptly notify the Representatives, so that any use of the Disclosure Package may cease until it is amended or supplemented, and will promptly prepare and file with the Commission, at its own expense, an amendment or supplement that will correct such statement or omission or an amendment that will effect such compliance.

     (e) If, at any time when a prospectus relating to the Offered Securities is required to be delivered under the Act in connection with sales by any Underwriter or dealer (including in circumstances where such requirement may be satisfied pursuant to Rule 172), any event occurs as a result of which the Final Prospectus as then amended or supplemented would include an untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, or if it is necessary at any time to amend the Final Prospectus to comply with the Act, the Company promptly will notify the Representatives of such event and will promptly prepare and file with the Commission, at its own expense, an amendment or supplement that will correct such statement or omission or an amendment that will effect such compliance. The terms “supplement” and “amendment” as used in this Agreement include, without limitation, all documents filed by the Company with the Commission subsequent to the date of the Final Prospectus that are deemed to be incorporated by reference in the Final Prospectus. Neither the Representatives’ consent to, nor the Underwriters’ delivery of, any such amendment or supplement shall constitute a waiver of any of the conditions set forth in Section 5 hereof.

     (f) As soon as practicable, but not later than 16 months, after the date of each Terms Agreement, the Company will make generally available to its security holders an earnings statement covering a period of at least 12 months beginning after the latest of (i) the effective date of the registration statement relating to the Registered Securities, (ii) the effective date of the most recent post-effective amendment to the Registration Statement to become effective prior to the date of such Terms Agreement and (iii) the date of the Company’s most recent Annual

Report on Form 10-K filed with the Commission prior to the date of such Terms Agreement, which will satisfy the provisions of Section 11(a) of the Act.

     (g) The Company will furnish to the Representatives copies of the Registration Statement, including all exhibits, and during any time when a prospectus relating to the Offered Securities is required to be delivered under the Act in connection with sales by any Underwriter or dealer (including in circumstances where such requirement may be satisfied pursuant to Rule 172), the Base Prospectus, any related Preliminary Final Prospectus, the Final Prospectus and each Issuer Free Writing Prospectus and all amendments and supplements to such documents, in each case as soon as available and in such quantities as the Representatives reasonably request.

     (h) The Company will use its reasonable best efforts to arrange for the qualification of the Offered Securities for sale and the determination of their eligibility for investment under the laws of such jurisdictions as the Representatives designate and will continue such qualifications in effect so long as required for the distribution; provided, however, that neither the Company nor CPCo will be required in connection therewith to register or qualify as a foreign corporation where it is not now so qualified or to execute a general consent to service of process in any jurisdiction or subject itself to taxation in any jurisdiction where it is not now so subject. The Company will promptly advise the Representatives of the receipt by it or CPCo of any notification with respect to the suspension of the qualification of the Offered Securities for offer and sale in any such jurisdiction or the initiation or threatening of any proceeding for such purpose.

     (i) During the period of five years after the date of any Terms Agreement, the Company will furnish or make available to the Representatives and, upon request, to each of the other Underwriters, if any, as soon as practicable after the end of each fiscal year, a copy of the Company’s annual report to stockholders for such year; and the Company will furnish or make available to the Representatives (i) as soon as available, a copy of each report (other than a report on Form 11-K) and any definitive proxy statement of the Company filed with the Commission under the Securities Exchange Act of 1934 or mailed to stockholders, and (ii) from time to time, such other information concerning the Company or CPCo as the Representatives may reasonably request in connection with the offering of the Offered Securities.

     (j) The Company will pay all expenses incident to the performance of its obligations under the Terms Agreement (including the provisions of this Agreement), for any filing fees or other expenses (including reasonable fees and disbursements of counsel) in connection with qualification of the Registered Securities for sale and determination of their eligibility for investment under the laws of such jurisdictions as the Representatives may designate in accordance with Section 4(h) and the printing of memoranda relating thereto, for any fees charged by investment rating agencies for the rating of the Offered Securities, for

any applicable filing fee incident to, and the reasonable fees and disbursements of counsel for the Underwriters in connection with, the review by the National Association of Securities Dealers, Inc. of the Registered Securities, for any travel expenses of the Company’s officers and employees and any other expenses of the Company in connection with attending or hosting meetings with prospective purchasers of Registered Securities and for expenses incurred in preparing, printing and distributing the Final Prospectus, any preliminary prospectuses, any preliminary prospectus supplements or any other amendments or supplements to the Final Prospectus to the Underwriters.

     (k) The Company agrees that, unless it has obtained or will obtain, as the case may be, the prior written consent of the Representatives, and each Underwriter, severally and not jointly, agrees with the Company that, unless it has obtained or will obtain, as the case may be, the prior written consent of the Company, it has not made and will not make any offer relating to the Offered Securities that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405) required to be filed by the Company with the Commission or retained by the Company under Rule 433, other than the final term sheet prepared and filed pursuant to Section 4(c) hereto; provided that the prior written consent of the parties hereto shall be deemed to have been given in respect of the Free Writing Prospectuses, if any, included in Schedule B to the applicable Terms Agreement. Any such free writing prospectus consented to by the Representatives or the Company is hereinafter referred to as a “ Permitted Free Writing Prospectus .” The Company agrees that (x) it has treated and will treat, as the case may be, each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus and (y) it has complied and will comply, as the case may be, with the requirements of Rules 164 and 433 applicable to any Permitted Free Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping.

     (l) The Company consents to the use by any Underwriter of a free writing prospectus that (a) is not an Issuer Free Writing Prospectus, and (b) contains only (i) information describing the preliminary terms of the Offered Securities or their offering, (ii) information required or permitted by Rule 134 under the Act that is not “issuer information” as defined in Rule 433 or (iii) information that describes the final terms of the Offered Securities or their offering and that is included in the final term sheet prepared and filed pursuant to Section 4(c) hereto.

     (m) The Company will not, and will cause CPCo not to, offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, or file with the Commission a registration statement under the Act relating to United States dollar-denominated debt securities issued or guaranteed by the Company or CPCo and having a maturity of more than one year from the date of issue, or publicly disclose the intention to make any such offer, sale, pledge, disposition or filing, without the prior written consent of the Representatives for a period beginning at the time of execution of the Terms Agreement and ending the number of days after the Closing Date specified under “Blackout” in the Terms Agreement.

     5.  Conditions of the Obligations of the Underwriters . The obligations of the several Underwriters to purchase and pay for the Offered Securities will be subject to the accuracy of the representations and warranties on the part of the Company herein, to the accuracy of the statements of Company officers made pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder and to the following additional conditions precedent:

     (a) Immediately after the Final Prospectus is filed with the Commission, the Representatives, on behalf of the Underwriters, shall have received a letter, dated as of the Execution Date, of Ernst & Young LLP confirming that they are independent registered public accountants within the meaning of the Act and the applicable published Rules and Regulations thereunder and stating to the effect that:

     (i) in their opinion the financial statements and any schedules audited by them and included or incorporated by reference in the Base Prospectus, Preliminary Final Prospectus, Final Prospectus and the Disclosure Package comply as to form in all material respects with the applicable accounting requirements of the Act and the related published Rules and Regulations;

     (ii) they have performed the procedures specified by the Public Company Accounting Oversight Board for a review of interim financial information as described in Statement of Auditing Standards No. 100, Interim Financial Information, on any unaudited financial statements included in the Registration Statement;

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

     (A) the unaudited financial statements, if any, included in the Disclosure Package or the Final Prospectus do not comply as to form in all material respects with the applicable accounting requirements of the Act and the related published Rules and Regulations or any material modifications should be made to such unaudited financial statements for them to be in conformity with generally accepted accounting principles;

     (B) if any unaudited “capsule” information is contained in the Disclosure Package or the Final Prospectus, the unaudited consolidated total revenues, net income and net income per share amounts or other amounts constituting such “capsule” information and described in such letter do not agree with the corresponding amounts set forth in the unaudited consolidated financial

statements or were not determined on a basis substantially consistent with that of the corresponding amounts in the audited statements of income;

     (C) at the date of the latest available consolidated balance sheet of the Company read by such accountants, there was any change in the capital stock, any increase in total debt, any decrease in consolidated net current assets (working capital) or any decrease in stockholders’ equity, as compared with amounts shown on the latest consolidated balance sheet included in the Disclosure Package or the Final Prospectus;

     (D) At a subsequent specified date not more than three business days prior to the date of such letter, there was any change greater than 1% in the capital stock, or any increase greater than 1% in total debt, as compared with the latest available consolidated balance sheet; or

     (E) for the period from the closing date of the latest income statement included in the Disclosure Package or the Final Prospectus to the closing date of the latest available income statement read by such accountants there were any decreases, as compared with the corresponding period of the previous year and with the period of corresponding length ended the date of the latest income statement included in the Disclosure Package or the Final Prospectus, in consolidated total revenues or net income;

except in all cases set forth in clauses (C), (D) and (E) above for changes, increases or decreases which the Disclosure Package and the Final Prospectus discloses have occurred or may occur or which are described in such letter;

     (iv) they have compared specified dollar amounts (or percentages derived from such dollar amounts) and other financial information contained in the Registration Statement, the Final Prospectus and the Disclosure Package (in each case to the extent that such dollar amounts, percentages and other financial information are derived from the general accounting records of the Company and its subsidiaries subject to the internal controls of the Company’s accoun