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                                                                    EXHIBIT 10.6





________________________________________________________________________________





                       FOURTH AMENDMENT TO THIRD AMENDED
                         AND RESTATED CREDIT AGREEMENT


                         dated as of December 22, 1995

                                     among

                               APACHE CORPORATION

                                      and

                    VARIOUS COMMERCIAL LENDING INSTITUTIONS,

                                      and

                      THE FIRST NATIONAL BANK OF CHICAGO,
                      as Administrative Agent and Arranger

                                      and

                                 CHEMICAL BANK,
                            as Co-Agent and Arranger





________________________________________________________________________________
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                       FOURTH AMENDMENT TO THIRD AMENDED
                         AND RESTATED CREDIT AGREEMENT


         THIS FOURTH AMENDMENT TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT,
dated as of December 22, 1995, (the "Fourth Amendment"), is among APACHE
CORPORATION, a Delaware corporation (the "Company"), the various commercial
lending institutions as are or may become parties hereto (the "Lenders"), THE
FIRST NATIONAL BANK OF CHICAGO, as Administrative Agent (in such capacity, the
"Administrative Agent") and Arranger (in such capacity, an "Arranger") and
CHEMICAL BANK, as Co-Agent (in such capacity, the "Co-Agent") and Arranger (in
such capacity, an "Arranger").

                              W I T N E S S E T H:

         1.      The Company, the Lenders, the Arrangers, the Co-Agent and the
Administrative Agent have heretofore entered into that certain Third Amended
and Restated Credit Agreement, dated as of March 1, 1995, as previously amended
(the "Credit Agreement").

         2.      The Company, the Lenders, the Arrangers, the Co-Agent and the
Administrative Agent now intend to amend the Credit Agreement (i) to permit
Apache Gathering Company to become a member of Producers Energy Marketing, LLC,
(ii) to permit the Company to guarantee the payment of obligations of Apache
Gathering Company to Producers Energy Marketing, LLC and (iii) to address
various other issues in connection therewith as follows:

         I.      AMENDMENTS TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT.

         A.      Section 1.1 of the Credit Agreement is hereby amended by
adding the following definition of "Producers Energy" in appropriate
alphabetical order:

                 "Producers Energy" means Producers Energy Marketing, LLC, a
Delaware limited liability company.

         B.      The definitions of "Contingent Obligation", "Indebtedness" and
"Subsidiary" appearing in Section 1.1 of the Credit Agreement are hereby
amended in their entirety to the following:

                 "Contingent Obligation" means, with respect to any Person as
         of the time a determination thereof is to be made, any obligation,
         contingent or otherwise, of any such Person, directly or indirectly,
         guaranteeing, endorsing or otherwise becoming contingently liable (by
         direct or indirect agreement, contingent or otherwise, to provide
         funds for payment, to supply funds to, or otherwise invest in, a
         debtor, or otherwise to assure a
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         creditor against loss) for any Indebtedness of itself or of any other
         Person (other than by endorsements of instruments in the course of
         business).

                 "Indebtedness" means, with respect to a Person, such Person's
         (i) obligations for borrowed money, (ii) obligations representing the
         deferred purchase price of property or services, including obligations
         payable out of Hydrocarbon production, other than accounts payable
         arising in the ordinary course of such Person's business payable on
         terms customary in the trade, (iii) obligations,  whether or not
         assumed, secured by Liens (other than Liens permitted by Section 11.5,
         clauses (a) through (d) or clauses (f) through (h)) or payable out of
         the proceeds of production from property now or hereafter owned or
         acquired by such Person, (iv) obligations which are evidenced by
         notes, bonds, debentures, acceptances, or other instruments, (v)
         Capitalized Lease Obligations, (vi) liabilities under interest rate
         swap, exchange, collar or cap agreements and all other agreements or
         arrangements designed to protect such Person against fluctuations in
         interest rates or currency exchange rates, (vii) liabilities under
         commodity hedge, commodity swap, exchange, collar or cap agreements,
         fixed price agreements and all other agreements or arrangements
         designed to protect a person against fluctuations in oil or gas
         prices, and (viii) obligations, contingent or otherwise, relative to
         the amount of all letters of credit, whether or not drawn, and (ix)
         all Contingent Obligations of such Person in respect of any of the
         foregoing; provided, however, that such term shall not include any
         amounts included as deferred credits on the financial statements of
         such Person or of a consolidated group including such Person,
         determined in accordance with Agreement Accounting Principles;
         provided furtherthat for purposes of the foregoing clauses (ii), (iii)
         and (ix), obligations pursuant to any oil, gas and/or mineral leases,
         farm-out agreements, division orders, contracts for the exchange or
         processing of oil, gas and/or other hydrocarbons, unitization and
         pooling declarations and agreements, operating agreements, development
         agreements, area of mutual interest agreements, marketing agreements
         or arrangements, and other agreements which are customary in the oil,
         gas and other mineral exploration, development and production business
         and in the business of processing of gas and gas condensate production
         for the extraction of products therefrom shall not be Indebtedness.

                 "Subsidiary" means, with respect to any Person, any other
         Person more than 50% of the outstanding voting securities of which
         shall at the time be owned or





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         controlled, directly or indirectly, by such Person; provided, that
         with respect to the Company, Subsidiaries shall include MW Petroleum,
         MWJR, each Drilling Partnership and any other Person more than 50% of
         the outstanding voting securities of which shall at the time be owned
         or controlled, directly or indirectly, by the Company or by one or
         more Subsidiaries or by the Company and one or more Subsidiaries;
         further provided, that, notwithstanding the foregoing, Subsidiaries of
         the Company shall not include, for the purposes of Article VIII
         (except for Sections 8.10, 8.15 and 8.16), Article IX, Article XI
         (except for Sections 11.2 and 11.9) and Article XII (except for
         Section 12.1 insofar as the representation or warranty which is
         breached or shall be false was made pursuant to Section 8.10, Section
         8.15 or Section 8.16), Apache Energy Limited and its Subsidiaries;
         further provided, that, notwithstanding the foregoing, Subsidiaries of
         the Company shall not include Producers Energy except for the purposes
         of Sections 8.10, 8.15, 8.16 and 12.1 (insofar as the representation
         or warranty which is breached or shall be false was made pursuant to
         Sections 8.10, 8.15 or 8.16).

         C.      Section 11.1 of the Credit Agreement is hereby amended by
deleting subsection 11.1(a) in its entirety and inserting the following before
the semicolon:

                 "(a)     The Obligations arising under the Loan Documents,
         Contingent Obligations permitted under Section 11.4 (whether or not
         then payable), and intercompany Indebtedness pursuant to Investments
         by the Company permitted by Sections 11.12(d), (e), (g), (h) and (i)".

         D.      Section 11.4 of the Credit Agreement is hereby amended (i) by
deleting "$45,000,000" from the fifth line of Section 11.4 and by replacing it
with "30,000,000"; (ii) by deleting subsection 11.4(h) in its entirety and
inserting the following before the comma:

         "(h) Contingent Obligations of the Company or any of its Subsidiaries
         in respect of itself or in respect of obligations of partnerships,
         corporations or limited liability companies of which the Company or
         its Subsidiaries are partners, shareholders or members, respectively,
         pursuant to any oil, gas and/or mineral leases, farm-out agreements,
         division orders, contracts for the sale, delivery, purchase, exchange,
         or processing of oil, gas and/or other hydrocarbons, unitization and
         pooling declarations and agreements, operating agreements, development
         agreements, area of mutual interest agreements, marketing agreements
         or





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         arrangements, and other agreements which are customary in the oil, gas
         and other mineral exploration, development and production business and
         in the business of processing of gas and gas condensate production for
         the extraction of products therefrom";

and (iii) by inserting the following after subsection 11.4(i) thereof before
the period:

         ", and (j) Contingent Obligations of the Company and any of its
         Subsidiaries to or in respect of Producers Energy which when
         aggregated with the Investments of the Company and any of its
         Subsidiaries permitted with respect to Producers Energy pursuant to
         subsection 11.12(c) do not exceed $30,000,000 in the aggregate".

         E.      Section 11.12 of the Credit Agreement is hereby amended by
deleting subsection 11.12(c) in its entirety and inserting the following before
the semicolon:

                 "(c)     without duplication, Investments permitted as
         Indebtedness pursuant to Section 11.1 and Investments permitted as
         Contingent Obligations pursuant to Section 11.4 (including, without
         limitation, Investments of the Company and any of its Subsidiaries in
         Producers Energy which when aggregated with the Contingent Obligations
         of the Company and any of its Subsidiaries permitted pursuant to
         subsection 11.4(j) do not exceed $30,000,000 in the aggregate)".

         F.      Section 14.7 of the Credit Agreement is hereby amended (i) by
deleting the word "or" at the end of subsection 14.7(b)(vi) and (ii) by
inserting the following after subsection 14.7(b)(vii) thereof:

         "or     (viii)  any investigation, litigation or proceeding related to
         any Investment by the Company, any of its Subsidiaries, Apache Energy
         Resources, Apache Energy Limited or Producers Energy in any Person,
         whether or not any Agent or any Lender is party thereto;".

         II.     EFFECTIVENESS.  This Fourth Amendment shall become effective
as of the date hereof when the Administrative Agent shall have received
counterparts hereof duly executed by the Company, the Required Lenders, the
Administrative Agent and the Co-Agent (or, in the case of any party as to which
an executed counterpart shall not have been received, telegraphic, telex, or
other written confirmation from such party of execution of a counterpart hereof
by such party).

         III.    REAFFIRMATION OF REPRESENTATIONS AND WARRANTIES.  To induce
the Lenders, the Administrative Agent, the Co-Agent and the





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Arrangers to enter into this Fourth Amendment, the Company hereby reaffirms, as
of the date hereof, its representations and warranties in their entirety
contained in Article VIII of the Credit Agreement and in all other documents
executed pursuant thereto (except to the extent such representations and
warranties relate solely to an earlier date) and additionally represents and
warrants as follows:

                 (i)      The Company is a corporation duly incorporated,
         validly existing and in good standing under the laws of its
         jurisdiction of incorporation and has all requisite authority, permits
         and approvals, and is in good standing to conduct its business in each
         jurisdiction in which its business is conducted.

                 (ii)     The Company has the corporate power and authority and
         legal right to execute and deliver this Fourth Amendment and to
         perform its obligations hereunder.  The execution and delivery by the
         Company of this Fourth Amendment and the performance of its
         obligations hereunder have been duly authorized by proper corporate
         proceedings, and this Fourth Amendment and the Credit Agreement, as
         amended hereby, constitute the legal, valid and binding obligations of
         the Company, enforceable against the Company in accordance with their
         terms, except as enforceability may be limited by bankruptcy,
         insolvency or similar laws affecting the enforcement of creditors'
         rights generally.

                 (iii)    No Default or Unmatured Default has occurred and is
         continuing as of the date hereof.

                 (iv)     There has been no material adverse change (a) in the
         businesses, assets, properties, operations, condition (financial or
         otherwise) or results of operations or prospects of the Company and
         its Subsidiaries from March 1, 1995, (b) affecting the rights and
         remedies of the Lenders under and in connection with this Fourth
         Amendment and the Credit Agreement, as amended by this Fourth
         Amendment, or (c) in the ability of the Company to perform its
         obligations under this Fourth Amendment or the Credit Agreement, as
         amended by this Fourth Amendment.1

                 (v)      There is no litigation, arbitration, governmental
         investigation, proceeding or inquiry pending or, to the knowledge of
         any of their officers threatened against or affecting the Company or
         its Subsidiaries which is or could have a Material Adverse Effect.

         IV.     DEFINED TERMS.  Except as amended hereby, terms used herein
when defined in the Credit Agreement shall have the same meanings herein unless
the context otherwise requires.





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         V.      REAFFIRMATION OF CREDIT AGREEMENT.  This Fourth Amendment
shall be deemed to be an amendment to the Credit Agreement, and the Credit
Agreement, as amended hereby, is hereby ratified, approved and confirmed in
each and every respect.  All references to the Credit Agreement herein and in
any other document, instrument, agreement or writing shall hereafter be deemed
to refer to the Credit Agreement as amended hereby.

         VI.     GOVERNING LAW.  THIS FOURTH AMENDMENT SHALL BE CONSTRUED IN
ACCORDANCE WITH THE INTERNAL LAWS (AND NOT THE LAW OF CONFLICTS) OF THE STATE
OF ILLINOIS, BUT GIVING EFFECT TO FEDERAL LAWS APPLICABLE TO NATIONAL BANKS.
All obligations of the Company and rights of the Lenders, the Administrative
Agent, the Co-Agent and the Arrangers and any other holders of the Notes
expressed herein shall be in addition to and not in limitation of those
provided by applicable law.

         VII.    SEVERABILITY OF PROVISIONS.  Any provision in this Fourth
Amendment that is held to be inoperative, unenforceable, or invalid in any
jurisdiction shall, as to that jurisdiction, be inoperative, unenforceable, or
invalid without affecting the remaining provisions in that jurisdiction or the
operation, enforceability, or validity of that provision in any other
jurisdiction, and to this end the provisions of this Fourth Amendment are
declared to be severable.

         VIII.   COUNTERPARTS.  This Fourth Amendment may be executed in any
number of counterparts, all of which taken together shall constitute one
agreement, and any of the parties hereto may execute this Fourth Amendment by
signing any such counterpart.

         IX.     HEADINGS.  Article and section headings in this Fourth
Amendment are for convenience of reference only, and shall not govern the
interpretation of any of the provisions of this Fourth Amendment.

         X.      SUCCESSORS AND ASSIGNS.  This Fourth Amendment shall be
binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns.

         XI.     NOTICE.  THIS WRITTEN FOURTH AMENDMENT TOGETHER WITH THE THIRD
AMENDED AND RESTATED CREDIT AGREEMENT AND THE OTHER 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 BETWEEN THE PARTIES.


                      [SIGNATURES BEGIN ON FOLLOWING PAGE]





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         IN WITNESS WHEREOF, the Company, the Lenders, the Administrative
Agent, the Co-Agent and the Arrangers have executed this Fourth Amendment as of
the date first above written.

                                        APACHE CORPORATION
                                        
                                        
                                        
                                        By:/s/ Clyde E. McKenzie               
                                           ------------------------------------
                                        Name:  Clyde E. McKenzie
                                        Title: Vice President and Treasurer
                                        
                                        
                                        THE FIRST NATIONAL BANK OF CHICAGO,
                                        Individually, as Administrative Agent
                                        and as Arranger
                                        
                                        
                                        
                                        By:/s/ Christine Frank                 
                                           ------------------------------------
                                        Name:  Christine Frank
                                        Title: Vice President
                                        
                                        
                                        CHEMICAL BANK, Individually, as 
                                        Co-Agent and as Arranger
                                        
                                        
                                        
                                        By:/s/ R. Potter                       
                                           ------------------------------------
                                        Name:  Ronald Potter
                                        Title: Managing Director
                                        
                                        
                                        BANK OF MONTREAL, Individually and as 
                                        Lead Manager
                                        
                                        
                                        
                                        By:/s/ Robert Roberts                  
                                           ------------------------------------
                                        Name:  Robert L. Roberts
                                        Title: Director, U.S. Corporate Banking





                                      S-1
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                                        CIBC INC., Individually and as Lead 
                                        Manager
                                        
                                        
                                        
                                        By:                                    
                                           ------------------------------------
                                        Name:
                                        Title:
                                        
                                        
                                        NATIONSBANK, Individually and as Lead 
                                        Manager
                                        
                                        
                                        
                                        By:/s/ Jo Tamalis                      
                                           ------------------------------------
                                        Name:  Jo A. Tamalis
                                        Title: Senior Vice President
                                        
                                        
                                        BANK OF AMERICA NATIONAL TRUST & 
                                        SAVINGS ASSOCIATION
                                        
                                        
                                        
                                        By:/s/ Laura B. Shepard                
                                           ------------------------------------
                                        Name:  Laura B. Shepard
                                        Title: Vice President
                                        
                                        
                                        BANQUE PARIBAS
                                        
                                        
                                        
                                        By:/s/ Charles K. Thompson             
                                           ------------------------------------
                                        Name:  Charles K. Thompson
                                        Title: Group Vice President
                                        
                                        
                                        By:/s/ G.J. Jeram                      
                                           ------------------------------------
                                        Name:  G.J. Jeram
                                        Title: Vice President
                                        
                                        
                                        SOCIETE GENERALE, SOUTHWEST AGENCY
                                        
                                        
                                        
                                        By:/s/ R.A. Erbert                     
                                           ------------------------------------
                                        Name:  Richard A. Erbert
                                        Title: Vice President





                                      S-2
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                                        MORGAN GUARANTY TRUST COMPANY OF
                                          NEW YORK
                                        
                                        
                                        
                                        By:/s/ P.W. McNeal                     
                                           ------------------------------------
                                        Name:  Philip W. McNeal
                                        Title: Vice President
                                        
                                        
                                        ABN-AMRO BANK N.V. - HOUSTON AGENCY
                                        
                                        
                                        
                                        By:/s/ Michael N. Oakes                
                                           ------------------------------------
                                        Name:  Michael N. Oakes
                                        Title: Vice President
                                        
                                        
                                        By:/s/ H. Gene Shiels                  
                                           ------------------------------------
                                        Name:  H. Gene Shiels
                                        Title: Vice President
                                        
                                        
                                        THE FIRST NATIONAL BANK OF BOSTON
                                        
                                        
                                        
                                        By:/s/ Michael Kane                    
                                           ------------------------------------
                                        Name:  Michael Kane
                                        Title: Managing Director
                                        
                                        
                                        THE BANK OF NOVA SCOTIA, SAN FRANCISCO
                                        AGENCY
                                        
                                        
                                        
                                        By:/s/ A.S. Norsworthy                 
                                           ------------------------------------
                                        Name:  A.S. Norsworthy
                                        Title: Assistant Agent
                                        
                                        
                                        THE CHASE MANHATTAN BANK, N.A.
                                        
                                        
                                        
                                        By:/s/ Bettylou J. Robert              
                                           ------------------------------------
                                        Name:  Bettylou J. Robert
                                        Title: Vice President
                                        




                                      S-3
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                                        CITIBANK, N.A.
                                        
                                        
                                        
                                        By:/s/ Carolyn R. Bodmer               
                                           ------------------------------------
                                        Name:  Carolyn R. Bodmer
                                        Title: Vice President
                                        
                                        
                                        THE FUJI BANK, LIMITED - HOUSTON AGENCY
                                        
                                        
                                        
                                        By:/s/ Soichi Yoshida                  
                                           ------------------------------------
                                        Name:  Soichi Yoshida
                                        Title: Vice President & Senior Manager
                                        
                                        
                                        UNION BANK OF SWITZERLAND, HOUSTON 
                                        AGENCY
                                        
                                        
                                        
                                        By:/s/ E. Swann                        
                                           ------------------------------------
                                        Name:  Evans Swann
                                        Title: Managing Director
                                        
                                        
                                        By:/s/ Kelly Boots                     
                                           ------------------------------------
                                        Name:  Kelly Boots
                                        Title: Assistant Treasurer
                                        
                                        
                                        UNION BANK
                                        
                                        
                                        
                                        By:/s/ Richard P. DeGrey               
                                           ------------------------------------
                                        Name:  Richard P. DeGrey
                                        Title: Vice President
                                        
                                        
                                        By:/s/ W.M. Roth                       
                                           ------------------------------------
                                        Name:  Walter M. Roth
                                        Title: Vice President





                                      S-4
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                                        CHRISTIANIA BANK OG KREDITKASSE
                                        
                                        
                                        
                                        By:/s/ Peter M. Dodge                  
                                           ------------------------------------
                                        Name:  Peter M. Dodge
                                        Title: Vice President
                                        
                                        
                                        
                                        By:/s/ Hans Chr. Kjelsrud              
                                           ------------------------------------
                                        Name:  Hans Chr. Kjelsrud
                                        Title: Vice President
                                        
                                        
                                        COLORADO NATIONAL BANK
                                        
                                        
                                        
                                        By:                                    
                                           ------------------------------------
                                        Name:
                                        Title:
                                        
                                        
                                        THE LONG-TERM CREDIT BANK OF JAPAN, LTD.
                                        
                                        
                                        
                                        By:/s/ S. Otsubo                       
                                           ------------------------------------
                                        Name:  Satoru Otsubo
                                        Title: Joint General Manager
                                        
                                        
                                        ROYAL BANK OF CANADA, GRAND CAYMAN
                                          (NORTH AMERICAN #1) BRANCH
                                        
                                        
                                        By:/s/ J.D. Frost                      
                                           ------------------------------------
                                        Name:  J.D. Frost
                                        Title: Senior Manager
                                        




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