EXHIBIT 10.73

                       FIRST AMENDMENT TO CREDIT AGREEMENT

      This First  Amendment to Credit  Agreement  (this  "AMENDMENT") is entered
into as of the 28th day of June, 1996, by and among Patina Oil & Gas Corporation
("PATINA"),  SOCO Wattenberg Corporation ("SWAT"), Gerrity Oil & Gas Corporation
("GERRITY"),  (Patina, SWAT and Gerrity are each individually referred to herein
as "BORROWER" and  collectively  as  "BORROWERS"),  Texas Commerce Bank National
Association,  as Administrative Agent ("ADMINISTRATIVE  AGENT"),  NationsBank of
Texas, N.A., as Documentary Agent ("DOCUMENTARY AGENT"), Wells Fargo Bank, N.A.,
CIBC, Inc. and Credit Lyonnais New York Branch,  as Co-Agents  ("CO-AGENTS") and
the  financial  institutions  listed on Schedule 1 to the Credit  Agreement  (as
hereinafter defined) as Banks (individually a "BANK" and collectively "BANKS").

                               W I T N E S E T H:

      WHEREAS, Borrowers, Administrative Agent, Documentary Agent, Co-Agents and
Banks are parties to that certain Credit  Agreement  dated as of May 2, 1996 the
"CREDIT AGREEMENT") (unless otherwise defined herein, all terms used herein with
their initial letter  capitalized shall have the meaning given such terms in the
Credit Agreement); and

     WHEREAS, pursuant to the Credit Agreement the Banks have made certain Loans
to Borrowers; and

      WHEREAS,  Borrowers have advised Banks that Patina has repurchased 135,400
shares of Common Stock in market transactions for an aggregate  consideration of
$923,345.00 (the "PATINA COMMON STOCK REPURCHASE"); and

      WHEREAS,  the Patina Common Stock  Repurchase  violates SECTION 9.2 of the
Credit Agreement and constitutes an Event of Default under the Credit Agreement;
and

      WHEREAS,  Borrowers  have  requested  that the  Banks  waive  the Event of
Default resulting from the Patina Common Stock Repurchase; and

      WHEREAS,  the Banks have agreed to grant such waiver on the condition that
the Credit Agreement be amended in certain respects.

      NOW  THEREFORE,  for and in  consideration  of the  mutual  covenants  and
agreements  herein  contained  and other good and  valuable  consideration,  the
receipt  and  sufficiency  of  which  are  hereby  acknowledged  and  confessed,
Borrowers, each Agent, and each Bank hereby agree as follows:

      SECTION 1.  AMENDMENTS.  In reliance on the  representations,  warranties,
covenants and agreements contained in this Amendment, the Credit Agreement shall
be amended effective June 28, 1996 (the "EFFECTIVE DATE") in the manner provided
in this Section 1.


                                 1





     1.1.  AMENDMENT TO  DEFINITIONS.  The  definitions  of "INITIAL  RESTRICTED
PAYMENT  LIMIT"  and  "LOAN  PAPERS"  contained  in  Section  1.1 of the  Credit
Agreement shall be amended to read in full as follows:

           "Initial  Restricted Payment Limit" means $11,000,000;  provided that
      such amount shall be allocated by Borrowers  between Patina and Gerrity on
      or before August 15, 1996, and Borrowers  shall notify Banks in writing of
      such  allocation  together  with the  delivery  to Banks of the  financial
      statements for the Fiscal Quarter ended June 30, 1996 required by SECTIONS
      8.1(B), (D) and (E); provided,  further,  that not more than $5,000,000 of
      the  Initial  Restricted  Payment  Limit  shall be  allocated  to  Patina.
      "Allocated Shares of Initial Restricted Payment Limit" means, with respect
      to Patina or Gerrity, that portion of the Initial Restricted Payment Limit
      allocated  to  Patina  or  Gerrity  (as   applicable)   pursuant  to  this
      definition.

           "Loan Papers" means this Agreement, the Notes, the Patina Guarantees,
      the Collateral Assignment of Intercompany Loan, the Tax Credit Transaction
      Agreement,  the Patina Pledge Agreement, the Gerrity Pledge Agreement, the
      First  Amendment,  all  Mortgages now or at any time  hereafter  delivered
      pursuant  to  SECTION  5.1,  and  all  other  certificates,  documents  or
      instruments delivered in connection with this Agreement,  as the foregoing
      may be amended from time to time.

     1.2. ADDITIONAL  DEFINITIONS.  Section 1.1 of the Credit Agreement shall be
amended to add the following definition to such Section:

           "First Amendment" means the First Amendment to Credit Agreement dated
      as of June 28, 1996,  entered  into by and among  Borrowers,  Agents,  and
      Banks.

      SECTION 2.WAIVER  REGARDING PATINA COMMON STOCK  REPURCHASE.  Banks hereby
waive  Borrowers'  obligation to comply with SECTION 9.2 of the Credit Agreement
to the extent, but only to the extent,  that SECTION 9.2 of the Credit Agreement
prohibits  the Patina  Common  Stock  Repurchase,  and Banks  waive the Event of
Default resulting from such Patina Common Stock Repurchase. Each Borrower hereby
acknowledges  that such  waiver is limited  solely to SECTION  9.2 of the Credit
Agreement,  and solely to the Patina Common Stock Repurchase.  Nothing contained
herein shall  obligate Banks to grant any additional or future waiver of SECTION
9.2 of the Credit Agreement or any other provision of any other Loan Paper.

      SECTION  3.REPRESENTATIONS  AND WARRANTIES.  In order to induce Agents and
Banks to enter into this  Amendment and grant the waiver  contained in SECTION 2
hereof, each Borrower hereby represents and warrants to each Agent and each Bank
that:

          (a)  each  representation  and  warranty  of  each  Borrower  and  the
     Restricted  Subsidiaries  contained in the Loan Papers are true and correct
     in all material  respects as of the date hereof  (except to the extent that
     such  representations  and warranties are expressly made as of a particular
     date,  in which event such  representations  and  warranties  were true and
     correct as of such date);

          (b) except for the Event of Default  under  Section  9.2 of the Credit
     Agreement  resulting  from the Patina  Common Stock  Repurchase,  neither a
     Default nor an Event of Default has occurred which is continuing; and

          (c) Borrowers have no defenses to payment,  counterclaims or rights of
     set-off with respect to the Obligations on the date hereof.

      SECTION 4.MISCELLANEOUS.

      4.1  REAFFIRMATION OF LOAN PAPERS;  EXTENSION OF LIENS. Any and all of the
terms and provisions of the Credit  Agreement and the Loan Papers shall,  except
as amended and modified hereby,  remain in full force and effect.  Each Borrower
hereby extends the Liens securing the  Obligations  until the  Obligations  have
been paid in full,  and agrees  that the  amendments  and  modifications  herein
contained  shall in no  manner  affect or impair  the  Obligations  or the Liens
securing payment and performance thereof.

      4.2 PARTIES IN INTEREST. All of the terms and provisions of this Amendment
shall bind and inure to the benefit of the parties  hereto and their  respective
successors and assigns.

      4.3 LEGAL  EXPENSES.  Each  Borrower  hereby  agrees to pay on demand  all
reasonable  fees and  expenses of counsel to  Administrative  Agent  incurred by
Administrative  Agent  in  connection  with  the  preparation,  negotiation  and
execution of this Amendment and all related documents.

      4.4 COUNTERPARTS.  This Amendment may be executed in counterparts, and all
parties need not execute the same counterpart;  however, no party shall be bound
by this  Amendment  until this  Amendment  has been  executed by  Borrowers  and
Required  Banks at which time this  Amendment  shall be binding on,  enforceable
against and inure to the benefit of Borrowers,  Agents and all Banks. Facsimiles
shall be effective as originals.

      4.5 COMPLETE AGREEMENT. THIS AMENDMENT, THE CREDIT AGREEMENT AND THE OTHER
LOAN  PAPERS  REPRESENT  THE FINAL  AGREEMENT  AMONG THE  PARTIES AND MAY NOT BE
CONTRADICTED  BY EVIDENCE OF PRIOR,  CONTEMPORANEOUS  OR ORAL  AGREEMENTS OF THE
PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

      4.6  HEADINGS.  The  headings,  captions  and  arrangements  used  in this
Amendment are, unless specified otherwise, for convenience only and shall not be
deemed to limit,  amplify or modify the terms of this Amendment,  nor affect the
meaning thereof.

      IN WITNESS  WHEREOF,  the parties  hereto have caused this Amendment to be
duly executed by their respective Authorized Officers on the date and year first
above written.

                                    BORROWERS:

                                    PATINA OIL & GAS CORPORATION,
                                    a Delaware corporation


                                    By:
                                    Its:

                                    SOCO WATTENBERG CORPORATION,
                                    a Delaware corporation


                                    By:
                                    Its:


                                    GERRITY OIL & GAS CORPORATION,
                                    a Delaware corporation


                                    By:
                                    Its:



                                 2






                                   ADMINISTRATIVE AGENT:

                                   TEXAS COMMERCE BANK
                                   NATIONAL ASSOCIATION


                                    By:
                                    Its:

                                    DOCUMENTARY AGENT:

                                    NATIONSBANK OF TEXAS, N.A.


                                    By:
                                    Its:

                                    CO-AGENTS:

                                    CIBC, INC.


                                    By:
                                    Its:

                                    CREDIT LYONNAIS NEW YORK BRANCH


                                    By:
                                    Its:

                                    BANKS:

                                    TEXAS COMMERCE BANK
                                    NATIONAL ASSOCIATION


                                    By:
                                    Its:


                                 3





                                    NATIONSBANK OF TEXAS, N.A.


                                    By:
                                    Its:

                                    CIBC, INC.


                                    By:
                                    Its:

                                    CREDIT LYONNAIS NEW YORK BRANCH


                                    By:
                                    Its:

                                    WELLS FARGO BANK, N.A.


                                    By:
                                    Its:


                                 4