<PAGE>
                                                                    EXHIBIT 10.4


                     THIRD AMENDMENT TO US CREDIT AGREEMENT


         THIS THIRD AMENDMENT TO US CREDIT AGREEMENT (herein called this
"Amendment") made as of July 31, 2001 by and among Devon Energy Corporation, a
Delaware corporation ("US Borrower"), Bank of America, N.A., individually and as
administrative agent ("US Agent"), and the US Lenders party to the Original
Agreement defined below ("US Lenders").

                                   WITNESSETH:

         WHEREAS, US Borrower, US Agent and US Lenders entered into that certain
US Credit Agreement dated as of August 29, 2000 (as amended, supplemented, or
restated to the date hereof, the "Original Agreement"), for the purpose and
consideration therein expressed, whereby US Lenders became obligated to make
loans to US Borrower as therein provided;

         WHEREAS, US Borrower, US Agent and US Lenders desire to amend the
Original Agreement as set forth herein;

         NOW, THEREFORE, in consideration of the premises and the mutual
covenants and agreements contained herein and in the Original Agreement, in
consideration of the loans which may hereafter be made by US Lenders to US
Borrower, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto do hereby agree
as follows:


                                   ARTICLE I.

                           Definitions and References

         Section 1.1. Terms Defined in the Original Agreement. Unless the
context otherwise requires or unless otherwise expressly defined herein, the
terms defined in the Original Agreement shall have the same meanings whenever
used in this Amendment.

         Section 1.2. Other Defined Terms. Unless the context otherwise
requires, the following terms when used in this Amendment shall have the
meanings assigned to them in this section.

                  "Amendment" means this Third Amendment to US Credit Agreement.

                  "US Agreement" means the Original Agreement as amended hereby.



                                          Third Amendment to US Credit Agreement
<PAGE>






                                   ARTICLE II.

                        Amendments to Original Agreement

         Section 2.1. Defined Terms.

         (a) The definition of "ERISA Plan" in Annex I of the Original Agreement
is hereby amended in its entirety to read as follows:

                  "'ERISA Plan' means any employee pension benefit plan (other
         than a Multiemployer Plan) subject to Title IV of ERISA maintained by
         any ERISA Affiliate with respect to which any Restricted Person has a
         fixed or contingent liability."

         (b) The definition of "Permitted Liens" in Annex I of the Original
Agreement is hereby amended by deleting subsection (w) thereof and adding the
following new subsections (w) and (x) in lieu thereof:

                  "(w) Liens on Margin Stock.

                  (x) in addition to Liens permitted by clauses (a) through (w)
         above, Liens on property or assets if the aggregate Indebtedness
         secured thereby does not exceed US $50,000,000."

         (c) The definition of "Termination Event" in Annex I of the Original
Agreement is hereby amended in its entirety to read as follows:

                  "'Termination Event' means (a) the occurrence with respect to
         any ERISA Plan of (i) a reportable event described in Sections
         4043(c)(5) or (6) of ERISA or (ii) any other reportable event described
         in Section 4043(c) of ERISA other than a reportable event not subject
         to the provision for 30-day notice to the Pension Benefit Guaranty
         Corporation pursuant to a waiver by such corporation under Section
         4043(a) of ERISA; or (b) the withdrawal of any ERISA Affiliate from an
         ERISA Plan during a plan year in which it was a "substantial employer"
         as defined in Section 4001(a)(2) of ERISA; or (c) a complete or partial
         withdrawal by any ERISA Affiliate from a Multiemployer Plan or
         notification that a Multiemployer Plan is in reorganization; or (d) the
         filing of a notice of intent to terminate any ERISA Plan or
         Multiemployer Plan or the treatment of any ERISA Plan amendment or
         Multiemployer Plan amendment as a termination under Section 4041 or
         4041A of ERISA; or (e) the institution of proceedings to terminate any
         ERISA Plan or Multiemployer Plan by the Pension Benefit Guaranty
         Corporation under Section 4042 of ERISA; or (f) any other event or
         condition which might constitute grounds under Section 4042 of ERISA
         for the termination of, or the appointment of a trustee to administer,
         any ERISA Plan or Multiemployer Plan."

         (d) The definition of "Total Capitalization" in Annex I of the Original
Agreement is hereby amended in its entirety to read as follows:


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                                          Third Amendment to US Credit Agreement
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                  "'Total Capitalization' means the sum (without duplication) of
         (i) US Borrower's Consolidated Total Funded Debt plus (ii) US
         Borrower's Consolidated shareholder's equity plus (iii) 60% of the
         outstanding balance of the Devon Trust Securities. Total Capitalization
         shall be calculated excluding non-cash write-downs and related charges
         which are required under Rule 4-10 (Financial Accounting and Reporting
         for Oil and Gas Producing Activities Pursuant to the Federal Securities
         Laws and the Energy Policy and Conservation Act of 1975) of Regulation
         S-X promulgated by Securities and Exchange Commission Regulation, or by
         US GAAP."

         (e) The first sentence of the definition of "Unrestricted Subsidiary"
in Annex I of the Original Agreement is hereby amended in its entirety to read
as follows (it being understood that the last sentence thereof and the list of
Unrestricted Subsidiaries set forth therein are not being modified by this
Amendment):

                  "'Unrestricted Subsidiary' means any corporation, association,
         partnership, limited liability company, joint venture, or other
         business or corporate entity, enterprise or organization (i) which is
         listed below in this definition, or (ii) in which US Borrower did not
         own an interest (directly or indirectly) as of August 29, 2000, which
         thereafter became a Subsidiary of US Borrower and which, within 90 days
         after becoming a Subsidiary of US Borrower, is designated as an
         Unrestricted Subsidiary by US Borrower to US Agent; provided that in
         the event any such Subsidiary becomes a Material Subsidiary at any
         time, such Subsidiary shall cease to be an Unrestricted Subsidiary at
         such time and shall automatically become a Restricted Subsidiary."

         (f) The following defined terms are hereby added to Annex I of the
Original Agreement in alphabetical order:

                  "'Disclosure Report' means a written notice given by US
         Borrower to all Lender Parties or a certificate given by the Senior
         Vice President-Finance or the Treasurer of US Borrower under Sections
         6.2(a) and (b)."

                  "'Multiemployer Plan' means a multiemployer plan within the
         meaning of Section 4001(a)(3) of ERISA to which any ERISA Affiliate is
         making or is obligated to make contributions or, during the five
         preceding plan years, has made or has been obligated to make
         contributions."

                  "'Margin Stock' means 'margin stock' as defined in Reg U."

                  "'Material Subsidiary' means a Subsidiary of US Borrower which
         owns assets having a book value that exceeds ten percent (10%) of the
         book value of US Borrower's Consolidated assets."

                  "'Reg U' means Regulation U promulgated by the Board of
         Governors of the Federal Reserve System."

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                                          Third Amendment to US Credit Agreement
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         Section 2.2. Use of Proceeds. Section 1.4 of the Original Agreement is
hereby amended in its entirety to read as follows:

                  "Section 1.4. Use of Proceeds. US Borrower shall use all US
         Loans made under this Agreement to refinance existing indebtedness
         (including any commercial paper issued by or for the account of US
         Borrower), to finance capital expenditures, to refinance Matured US LC
         Obligations outstanding under this Agreement, and to provide working
         capital for its operations and for other general business purposes. US
         Borrower shall use all Letters of Credit for its general corporate
         purposes. If any US Loan is used for a purpose which is governed by Reg
         U, US Borrower shall comply with Reg U in all respects. US Borrower
         represents and warrants that US Borrower is not engaged principally, or
         as one of US Borrower's important activities, in the business of
         extending credit to others for the purpose of purchasing or carrying
         Margin Stock."

         Section 2.3. Default Rate. Section 1.5(f) of the Original Agreement is
hereby amended in its entirety to read as follows:

                  "(f) All US Loans. All past due principal of and past due
         interest on the US Loans shall bear interest on each day outstanding at
         the applicable Default Rate in effect on such day, and such interest
         shall be due and payable daily as it accrues."

         Section 2.4. Conditions Precedent. Section 4.3(c) of the Original
Agreement is hereby deleted.

         Section 2.5. Representations and Warranties; Litigation and ERISA Plans
and Liabilities. Sections 5.2, 5.7 and 5.8 of the Original Agreement are hereby
amended in their entirety to read as follows:

                  "Section 5.2 Organization and Good Standing. Each of US
         Borrower and the Material Subsidiaries is duly organized, validly
         existing and in good standing under the Laws of its jurisdiction of
         organization, having all powers required to carry on its business and
         enter into and carry out the transactions contemplated hereby. Each of
         US Borrower and the Material Subsidiaries is duly qualified, in good
         standing, and authorized to do business in all other jurisdictions
         within the United States wherein the character of the properties owned
         or held by it or the nature of the business transacted by it makes such
         qualification necessary except where failure to so qualify would not
         have a Material Adverse Effect. Each of US Borrower and the Material
         Subsidiaries has taken all actions and procedures customarily taken in
         order to enter, for the purpose of conducting business or owning
         property, each jurisdiction outside the United States wherein the
         character of the properties owned or held by it or the nature of the
         business transacted by it makes such actions and procedures desirable
         except where failure to so qualify would not have a Material Adverse
         Effect.

                  Section 5.7. Litigation. Except as disclosed in the Initial
         Financial Statements, in the financial statements delivered to Agent
         and Lenders pursuant to Section 6.2, in the Disclosure Schedule or in a
         Disclosure Report, there are no actions, suits or legal,

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                                          Third Amendment to US Credit Agreement
<PAGE>

         equitable, arbitrative or administrative proceedings pending, or to the
         knowledge of any Restricted Person threatened, against any Restricted
         Person before any Tribunal which would reasonably be expected to have a
         Material Adverse Effect, and there are no outstanding judgments,
         injunctions, writs, rulings or orders by any such Tribunal against any
         Restricted Person which would reasonably be expected to have a Material
         Adverse Effect.

                  Section 5.8. ERISA Plans and Liabilities. All currently
         existing ERISA Plans and Multiemployer Plans are listed in the
         Disclosure Schedule or in a Disclosure Report. Except as disclosed in
         the Initial Financial Statements, in the Disclosure Schedule or in a
         Disclosure Report, no Termination Event has occurred with respect to
         any ERISA Plan or any Multiemployer Plan and all ERISA Affiliates are
         in compliance with ERISA in all material respects. Except as set forth
         in the Disclosure Statement or in a Disclosure Report, (i) no
         "accumulated funding deficiency" (as defined in Section 412(a) of the
         Internal Revenue Code) exists with respect to any ERISA Plan, whether
         or not waived by the Secretary of the Treasury or his delegate, (ii)
         the total amount of withdrawal liability that would be incurred by all
         ERISA Affiliates upon their complete withdrawal from all Multiemployer
         Plans would not reasonably be expected to exceed US $125,000,000, and
         (iii) the total present value of all unfunded benefit liabilities
         within the meaning of Title IV of ERISA of all ERISA Plans (based upon
         the actuarial assumptions used to fund each such Plan) did not, as of
         the respective annual valuation dates for the most recently ended plan
         year of each such Plan, exceed US $125,000,000."

         Section 2.6. Representations and Warranties; Names and Places of
Business. Section 5.10 of the Original Agreement is hereby deleted in its
entirety.

         Section 2.7. Representations and Warranties; US Borrower's
Subsidiaries; Title to Properties; Licenses. Sections 5.11 and 5.12 of the
Original Agreement are hereby amended in their entirety to read as follows:

                  "Section 5.11. US Borrower's Subsidiaries. US Borrower does
         not presently have any Material Subsidiary except those listed in the
         Disclosure Schedule or in a Disclosure Report (it being understood that
         inclusion of a Subsidiary on the Disclosure Schedule does not mean that
         such Subsidiary is a Material Subsidiary). US Borrower owns, directly
         or indirectly, the equity interest in each of its Material Subsidiaries
         which is indicated in the Disclosure Schedule or in a Disclosure
         Report.

                  Section 5.12. Title to Properties; Licenses. Each Restricted
         Person has good and defensible title to all of its material properties
         and assets, free and clear of all Liens other than Permitted Liens and
         of all impediments to the use of such properties and assets in such
         Restricted Person's business except to the extent failure to have such
         title would not have a Material Adverse Effect. Each Restricted Person
         possesses all licenses, permits, franchises, patents, copyrights,
         trademarks and trade names, and other intellectual property (or
         otherwise possesses the right to use such intellectual property) which
         are necessary to carry out its business as presently conducted and as
         presently proposed to be

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                                          Third Amendment to US Credit Agreement
<PAGE>

         conducted hereafter except to the extent failure to possess such
         licenses, permits, franchises, and intellectual property would not have
         a Material Adverse Effect, and no Restricted Person is in violation in
         any material respect of the terms under which it possesses such
         intellectual property or the right to use such intellectual property
         except to the extent any such violation would not have a Material
         Adverse Effect."

         Section 2.8. Representations and Warranties; Insider. Section 5.14 of
the Original Agreement is hereby deleted in its entirety.

         Section 2.9. Notice of Material Events and Change of Address. Section
6.4 of the Original Agreement is hereby amended to replace all references
therein to the amount of "$100,000,000" to "$125,000,000", to delete the last
sentence of such section, and to amend clause (d) thereof in its entirety to
read as follows:

                  "(d) the occurrence of any Termination Event which could
         reasonably be expected to cause (i) the total amount of withdrawal
         liability that would be incurred by all ERISA Affiliates upon their
         complete withdrawal from all Multiemployer Plans to exceed US
         $125,000,000, or (ii) the aggregate Liabilities of the ERISA Affiliates
         to ERISA Plans to exceed $125,000,000."

         Section 2.10. Environmental Matters. Section 6.12(b) of the Original
Agreement is hereby amended to replace the reference therein to the amount of
"$100,000,000" to "$125,000,000."

         Section 2.11. Indebtedness. Subsections (b) and (m) of Section 7.1 of
the Original Agreement are hereby amended in their entirety to read as follows:

                  "(b) capital lease obligations (excluding oil, gas or mineral
         leases) entered into in the ordinary course of such Restricted Person's
         business in arm's length transactions at competitive market rates under
         competitive terms and conditions in all respects, provided that such
         capital lease obligations required to be paid in any Fiscal Year do not
         in the aggregate exceed US $50,000,000 for all Restricted Subsidiaries.

                  (m) miscellaneous items of Indebtedness of all Restricted
         Persons (other than US Borrower) not described in subsections (a)
         through (m) which do not in the aggregate exceed US $400,000,000 in
         principal amount at any one time outstanding."

         Section 2.12. Limitation on Restricted Payments. Section 7.5 of the
Original Agreement is hereby deleted.

         Section 2.13. Prohibited Contracts. Section 7.7 of the Original
Agreement is hereby amended in its entirety to read as follows:

                  "Section 7.7. Prohibited Contracts; ERISA. Except as expressly
         provided for in the US Loan Documents, the Support Agreement dated
         December 10, 1998 between the US Borrower and Northstar Energy, the
         Santa Fe Snyder Indentures, and documents and

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                                          Third Amendment to US Credit Agreement
<PAGE>

         instruments evidencing or governing Acquired Debt, no Restricted Person
         will, directly or indirectly, enter into, create, or otherwise allow to
         exist any contract or other consensual restriction on the ability of
         any Restricted Person that is a Subsidiary of US Borrower to pay
         dividends or make other distributions to US Borrower, to redeem equity
         interests held in it by US Borrower, to repay loans and other
         indebtedness owing by it to US Borrower, or to transfer any of its
         assets to US Borrower."

         Section 2.14. Events of Default. Subsection (c), (e) and (f) of Section
8.1 of the Original Agreement are hereby amended in their entirety to read as
follows:

                  "(c) Any Restricted Person fails (other than as referred to in
         subsections (a) or (b) above) to (i) duly comply with Section 1.4 or
         Section 7.4(b) of the US Agreement or (ii) duly observe, perform or
         comply with any other covenant, agreement, condition or provision of
         any US Loan Document, and such failure remains unremedied for a period
         of thirty (30) days after notice of such failure is given by US Agent
         to US Borrower;

                  (e) Any Restricted Person fails to duly pay any Indebtedness
         in excess of US $125,000,000 constituting principal or interest owed by
         it with respect to borrowed money or money otherwise owed under any
         note, bond, or similar instrument, or (ii) breaches or defaults in the
         performance of any agreement or instrument by which any such
         Indebtedness is issued, evidenced, governed, or secured, other than a
         breach or default described in clause (i) above, and any such failure,
         breach or default results in the acceleration of such Indebtedness;
         provided that notwithstanding any provision of this subsection (e) to
         the contrary, to the extent that the terms of any such agreement or
         instrument governing the sale, pledge or disposal of Margin Stock or
         utilization of the proceeds of such Indebtedness in connection
         therewith would result in such acceleration and in a Default or an
         Event of Default under this Agreement, and would cause this Agreement
         or any US Loan to be subject to the margin requirements or any other
         restriction under Reg U, then such acceleration shall not constitute a
         Default or Event of Default under this subsection (e);

                  (f) Either of the following occurs: (i) a Termination Event
         occurs and the total amount of withdrawal liability that would be
         incurred by all ERISA Affiliates upon their complete withdrawal from
         all Multiemployer Plans would reasonably be expected to exceed US
         $125,000,000, or (ii) a Termination Event occurs and the total present
         value of all unfunded benefit liabilities within the meaning of Title
         IV of ERISA of all ERISA Plans (based upon the actuarial assumptions
         used to fund each such Plan) would reasonably be expected to exceed US
         $125,000,000";

         Section 2.15. Additional Events of Default. Section 8.1(h) is hereby
amended by replacing all references therein to the amount of "$100,000,000" to
"$125,000,000."

         Section 2.16. Amendments to Statutes and Regulations. Section 10.16 of
the Original Agreement is hereby amended by adding the following sentence at the
end thereof:

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                  "Unless the context otherwise requires or unless otherwise
         provided herein, the references in this Agreement to a particular
         statute, rule or regulation also refer to and include all amendments,
         supplements and other modifications to such statute, rule or
         regulation."

         Section 2.17. Disclosure Schedule. Paragraph 6 of the Disclosure
Schedule to the Original Agreement is hereby amended by adding the name of the
following Subsidiary thereto:

                  Canadian Mustang Energy Inc.

         Section 2.18. Tranche A Notes. Each Tranche A Note (and the form of
Tranche A Note attached as Exhibit A-1 to the Original Agreement) are hereby
amended by deleting the proviso at the end of the first sentence of the fourth
paragraph thereof which reads as follows: "; provided that if an Event of
Default has occurred and is continuing, such Loans shall bear interest on each
day outstanding at the applicable Default Rate in effect on such day". Each
Tranche A Note (and the form of Tranche A Note attached as Exhibit A-1 to the
Original Agreement) are hereby further amended by deleting the proviso at the
end of the third sentence of the fourth paragraph thereof which reads as
follows: "; provided that if an Event of Default has occurred and is continuing,
such Loan shall bear interest on each day outstanding at the applicable Default
Rate in effect on such day."

         Section 2.19. Tranche B Notes. Each Tranche B Note (and the form of
Tranche B Note attached as Exhibit A-2 to the Original Agreement) are hereby
amended by deleting the proviso at the end of the first sentence of the fourth
paragraph thereof which reads as follows: "; provided that if an Event of
Default has occurred and is continuing, such Loans shall bear interest on each
day outstanding at the applicable Default Rate in effect on such day." Each
Tranche B Note (and the form of Tranche B Note attached as Exhibit A-2 to the
Original Agreement) are hereby further amended by deleting the proviso at the
end of the third sentence of the fourth paragraph thereof which reads as
follows: "; provided that if an Event of Default has occurred and is continuing,
such Loan shall bear interest on each day outstanding at the applicable Default
Rate in effect on such day."

         Section 2.20. US Swing Note. The US Swing Note (and the form of US
Swing Note attached as Exhibit A-3 to the Original Agreement) are hereby amended
by deleting the proviso at the end of the first sentence of the fourth paragraph
thereof which reads as follows: "; provided that if an Event of Default has
occurred and is continuing, such Loans shall bear interest on each day
outstanding at the applicable Default Rate in effect on such day."

         Section 2.21. Competitive Bid Notes. Each Competitive Bid Note issued
under the US Agreement (and the form of Competitive Bid Note attached as Exhibit
L to the Original Agreement) are hereby amended by deleting the proviso at the
end of the first sentence of the fifth paragraph thereof which reads as follows:
"; provided that if an Event of Default has occurred and is continuing, such
Competitive Bid Loan shall bear interest on each day outstanding at the
applicable Default Rate in effect on such day."


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                                          Third Amendment to US Credit Agreement
<PAGE>

                                  ARTICLE III.

                           Conditions of Effectiveness

         Section 3.1. Effective Date. This Amendment shall become effective as
of the date first above written when and only when:

         (a) US Agent shall have received all of the following, at US Agent's
office, duly executed and delivered and in form and substance satisfactory to US
Agent, all of the following:

                  (i) this Amendment executed by US Borrower, US Agent and US
         Required Lenders; provided that the amendment set forth in Section 2.3
         hereof, insofar as it applies to the Tranche A Notes, and in Section
         2.18 hereof shall become effective only when executed and delivered by
         all Tranche A Lenders, the amendment set forth in Section 2.3 hereof,
         insofar as it applies to the Tranche B Notes, and in Section 2.19
         hereof shall become effective only when executed and delivered by all
         Tranche B Lenders, the amendment set forth in Section 2.3 hereof,
         insofar as it applies to the US Swing Note, and in Section 2.20 hereof
         shall become effective only when executed and delivered by the US Swing
         Lender, and the amendment set forth in Section 2.3 hereof, insofar as
         it applies to any Competitive Bid Note, and in Section 2.21 hereof
         shall become effective only when executed and delivered by the holder
         of such Competitive Bid Note; and provided further that the amendment
         set forth in Section 2.4 of this Amendment shall become effective only
         when executed and delivered by all US Lenders.

                  (ii) a certificate of the Senior Vice President - Finance or
         the Treasurer of US Borrower dated the date of this Amendment
         certifying: (i) that all of the representations and warranties set
         forth in Article IV hereof are true and correct at and as of such date,
         and (ii) that no Default exists at and as of such date.

         (b) US Borrower shall have paid, in connection with such US Loan
Documents, all fees and reimbursements to be paid to US Agent pursuant to any US
Loan Documents, or otherwise due US Agent and including fees and disbursements
of US Agent's attorneys.


                                   ARTICLE IV.

                         Representations and Warranties

         Section 4.1. Representations and Warranties of US Borrower. In order to
induce each US Lender to enter into this Amendment, US Borrower represents and
warrants to each US Lender that:

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                                          Third Amendment to US Credit Agreement
<PAGE>

         (a) The representations and warranties contained in Article V of the
Original Agreement are true and correct at and as of the time of the
effectiveness hereof, except to the extent that the facts on which such
representations and warranties are based have been changed by the extension of
credit under the US Agreement.

         (b) US Borrower is duly authorized to execute and deliver this
Amendment and is and will continue to be duly authorized to borrow monies and to
perform its obligations under the US Agreement. US Borrower has duly taken all
corporate action necessary to authorize the execution and delivery of this
Amendment and to authorize the performance of the obligations of US Borrower
hereunder.

         (c) The execution and delivery by US Borrower of this Amendment, the
performance by US Borrower of its obligations hereunder and the consummation of
the transactions contemplated hereby do not and will not (i) conflict with any
provision of (A) any Law, (B) the organizational documents of US Borrower, or
(C) any agreement, judgment, license, order or permit applicable to or binding
upon US Borrower unless such conflict would not reasonably be expected to have a
Material Adverse Effect, or (ii) result in or require the creation of any Lien
upon any assets or properties of US Borrower which would reasonably be expected
to have a Material Adverse Effect, except as expressly contemplated or permitted
in the Loan Documents. Except as expressly contemplated in the Loan Documents no
consent, approval, authorization or order of, and no notice to or filing with,
any Tribunal or third party is required in connection with the execution,
delivery or performance by US Borrower of this Amendment or to consummate any
transactions contemplated by this Amendment, unless failure to obtain such
consent would not reasonably be expected to have a Material Adverse Effect.

         (d) When duly executed and delivered, each of this Amendment and the US
Agreement will be a legal and binding obligation of US Borrower, enforceable in
accordance with its terms, except as limited by bankruptcy, insolvency or
similar laws of general application relating to the enforcement of creditors'
rights and by equitable principles of general application.


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                                          Third Amendment to US Credit Agreement
<PAGE>





         (e) The audited annual Consolidated financial statements of US Borrower
dated as of December 31, 2000 and the unaudited quarterly Consolidated financial
statements of US Borrower dated as of March 31, 2001 fairly present the
Consolidated financial position at such dates and the Consolidated statement of
operations and the changes in Consolidated financial position for the periods
ending on such dates for US Borrower. Copies of such financial statements have
heretofore been delivered to each US Lender. Since such dates no material
adverse change has occurred in the Consolidated financial condition or
businesses of US Borrower.


                                   ARTICLE V.

                                  Miscellaneous

         Section 5.1. Ratification of Agreements. The Original Agreement and the
US Notes as hereby amended are hereby ratified and confirmed in all respects.
The US Loan Documents, as they may be amended or affected by this Amendment, are
hereby ratified and confirmed in all respects. Any reference to the US Agreement
in any Loan Document shall be deemed to be a reference to the Original Agreement
as hereby amended. The execution, delivery and effectiveness of this Amendment
shall not, except as expressly provided herein, operate as a waiver of any
right, power or remedy of US Lenders under the US Agreement or any other US Loan
Document nor constitute a waiver of any provision of the US Agreement or any
other US Loan Document.

         Section 5.2. Survival of Agreements. All representations, warranties,
covenants and agreements of US Borrower herein shall survive the execution and
delivery of this Amendment and the performance hereof, including without
limitation the making or granting of the Loans, and shall further survive until
all of the Obligations are paid in full. All statements and agreements contained
in any certificate or instrument delivered by US Borrower or any Restricted
Person hereunder or under the US Agreement to any US Lender shall be deemed to
constitute representations and warranties by, and/or agreements and covenants
of, US Borrower under this Amendment and under the US Agreement.

         Section 5.3. US Loan Documents. This Amendment is a US Loan Document,
and all provisions in the US Agreement pertaining to US Loan Documents apply
hereto.

         Section 5.4. Governing Law. This Amendment shall be governed by and
construed in accordance the laws of the State of Texas and any applicable laws
of the United States of America in all respects, including construction,
validity and performance.

         Section 5.5. Counterparts; Fax. This Amendment may be separately
executed in counterparts and by the different parties hereto in separate
counterparts, each of which when so executed shall be deemed to constitute one
and the same Amendment. This Amendment may be validly executed by facsimile or
other electronic transmission.



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                                          Third Amendment to US Credit Agreement
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         THIS AMENDMENT AND THE OTHER US LOAN DOCUMENTS REPRESENT THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO
UNWRITTEN ORAL AGREEMENTS OF THE PARTIES.



                                          Third Amendment to US Credit Agreement
<PAGE>




         IN WITNESS WHEREOF, this Amendment is executed as of the date first
above written.



                                          DEVON ENERGY CORPORATION
                                          US Borrower


                                          By:  /s/  William T. Vaughn
                                               -------------------------------
                                               William T. Vaughn
                                               Senior Vice President - Finance

                                          BANK OF AMERICA, N.A.,
                                          Administrative Agent, US LC Issuer
                                          and Lender


                                          By:  /s/  James R. Allred
                                               -------------------------------
                                               Name:  James R. Allred
                                               Title: Managing Director

                                          BANK OF MONTREAL
                                          Lender


                                          By:  /s/  J. B. Whitmore
                                               -------------------------------
                                               Name:  J. B. Whitmore
                                               Title: Managing Director

                                          BANK ONE, NA
                                          Lender


                                          By:  /s/  Ronald L. Dierker
                                               -------------------------------
                                               Name:  Ronald L. Dierker
                                               Title: Director, Capital Markets

                                          THE CHASE MANHATTAN BANK
                                          Lender


                                          By:  /s/  Russell A. Johnson
                                               -------------------------------
                                               Name:  Russell A. Johnson
                                               Title: Vice President



                                          Third Amendment to US Credit Agreement
<PAGE>

                                            UMB BANK
                                            Lender


                                            By:  /s/  Richard J. Lehrter
                                                 -------------------------------
                                                 Name:  Richard J. Lehrter
                                                 Title: Community Bank President

                                            FIRST UNION NATIONAL BANK
                                            Lender


                                            By:  /s/  David Humphreys
                                                 -------------------------------
                                                 Name:  David Humphreys
                                                 Title: Vice President

                                            TORONTO-DOMINION (TEXAS), INC.
                                            Lender


                                            By:  /s/  Debbie A. Greene
                                                 -------------------------------
                                                 Name:  Debbie A. Greene
                                                 Title: Vice President

                                            WESTDEUTSCHE LANDESBANK GIROZENTRALE
                                            Lender


                                            By:  /s/  Salvatore Battinelli
                                                 -------------------------------
                                                 Name:  Salvatore Battinelli
                                                 Title: Managing Director,
                                                        Credit Dept.


                                            By:  /s/  Water T. Duffy III
                                                 -------------------------------
                                                 Name:  Walter T. Duffy III
                                                 Title: Associate Director

                                            THE BANK OF NEW YORK
                                            Lender


                                            By:  /s/  Raymond J. Palmer
                                                 -------------------------------
                                                 Name:  Raymond J. Palmer
                                                 Title: Vice President


                                          Third Amendment to US Credit Agreement

<PAGE>

                                            ROYAL BANK OF CANADA
                                            Lender


                                            By:  /s/  Tom J. Oberaigner
                                                 -------------------------------
                                                 Name:  Tom J. Oberaigner
                                                 Title: Senior Manager

                                            SUNTRUST BANK, ATLANTA
                                            Lender


                                            By:  /s/  David J. Edge
                                                 -------------------------------
                                                 Name:  David J. Edge
                                                 Title: Director

                                            MORGAN GUARANTY TRUST COMPANY OF NEW
                                            YORK
                                            Lender


                                            By:  /s/    Russell A. Johnson
                                                 ------------------------------
                                                 Name:  Russell A. Johnson
                                                 Title: Vice President

                                            CITIBANK, N.A.
                                            Lender


                                            By:  /s/  Lydia G. Junek
                                                 -------------------------------
                                                 Name:  Lydia G. Junek
                                                 Title: Attorney-in-fact

                                            DEUTSCHE BANK AG NEW YORK BRANCH
                                            AND/OR CAYMAN ISLANDS BRANCH
                                            Lender

                                            By:  /s/  Michael E. Keating
                                                 -------------------------------
                                                 Name:  Michael E. Keating
                                                 Title: Managing Director

                                            By:  /s/  Joel Makowsky
                                                 -------------------------------
                                                 Name:  Joel Makowksy
                                                 Title: Vice President



                                          Third Amendment to US Credit Agreement
<PAGE>

                                            CIBC, INC.
                                            Lender


                                            By:  /s/  Nora Q. Catiis
                                                 -------------------------------
                                                 Name:  Nora Q. Catiis
                                                 Title: Authorized Signatory

                                            ABN AMRO BANK, N.V.
                                            Lender


                                            By:  /s/  Frank R. Russo, Jr.
                                                 -------------------------------
                                                 Name:  Frank R. Russo, Jr.
                                                 Title: Group Vice President


                                            By:  /s/  Dana Montgomery
                                                 -------------------------------
                                                 Name:  Dana Montgomery
                                                 Title: Vice President

                                            BAYERISCHE LANDESBANK GIROZENTRALE,
                                            CAYMAN ISLANDS BRANCH
                                            Lender


                                            By:  /s/  Hereward Drummond
                                                 -------------------------------
                                                 Name:  Hereward Drummond
                                                 Title: Senior Vice President


                                            By:  /s/  James H. Boyle
                                                 -------------------------------
                                                 Name:  James H. Boyle
                                                 Title: Vice President

                                            THE FUJI BANK, LIMITED
                                            Lender


                                            By:  /s/  Jacques Azagury
                                                 -------------------------------
                                                 Name:  Jacques Azagury
                                                 Title: Senior Vice President &
                                                        Manager



                                          Third Amendment to US Credit Agreement
<PAGE>

                                            CREDIT LYONNAIS NEW YORK BRANCH
                                            Lender


                                            By:  /s/  Jacques Busquet
                                                 -------------------------------
                                                 Name:  Jacques Busquet
                                                 Title: Executive Vice President

                                            BANK OF TOKYO - MITSUBISHI LTD.
                                            HOUSTON AGENCY
                                            Lender


                                            By:  /s/  K. Glasscock
                                                 -------------------------------
                                                 Name:  K. Glasscock
                                                 Title: Vice President & Manager


                                          Third Amendment to US Credit Agreement

<PAGE>



                             COMPLIANCE CERTIFICATE

                            DEVON ENERGY CORPORATION



         Reference is made to that certain Third Amendment to US Credit
Agreement dated as of July 31, 2001 (the "Third Amendment"), among Devon Energy
Corporation ("US Borrower") and Bank of America, N.A., individually and as
administrative agent ("US Agent"), and certain financial institutions
("Lenders"). Terms which are defined in the Third Amendment and which are used
but not defined herein shall have the meanings given them in the Third
Amendment. The undersigned, William T. Vaughn and Dale Wilson, do hereby certify
that they have made a thorough inquiry into all matters certified herein and,
based upon such inquiry, experience, and the advice of counsel, do hereby
further certify that:

         1. They are the duly elected, qualified, and acting Senior Vice
President-Finance and Treasurer, respectively, of US Borrower.

         2. All representations and warranties made by any Restricted Person in
any Loan Document delivered on or before the date hereof are true on and as of
the date hereof (except to the extent that the facts upon which such
representations are based have been changed by the transactions contemplated in
the Third Amendment) as if such representations and warranties had been made as
of the date hereof.

         3. No Default exists on the date hereof.

         4. Each Restricted Person has performed and complied with all
agreements and conditions required in the Loan Documents to be performed or
complied with by it on or prior to the date hereof.

         IN WITNESS WHEREOF, this instrument is executed by the undersigned as
of July 31, 2001.




                                /s/  William T. Vaughn
                                ------------------------------------------------
                                William T. Vaughn, Senior Vice President-Finance



                                /s/  Dale Wilson
                                ------------------------------------------------
                                Dale Wilson, Treasurer