EXHIBIT 10(a)


                            SIXTH AMENDMENT TO FIRST
                            RESTATED CREDIT AGREEMENT



               SIXTH AMENDMENT TO FIRST RESTATED CREDIT AGREEMENT

     This Sixth  Amendment  to First  Restated  Credit  Agreement  (this  "Sixth
Amendment")  is  entered  into  as of the  30th  day  of  September,  1999  (the
"Effective Date"), by and among Denbury  Resources,  Inc. ("DRI"), a corporation
previously  incorporated  under the Canadian Business  Corporation Act which has
been domesticated in the State of Delaware,  Bank of America, N.A., successor by
merger to NationsBank,  N.A., successor by merger to NationsBank of Texas, N.A.,
as Administrative Agent ("Agent"), and the financial institutions parties hereto
as Banks ("Banks").

                              W I T N E S S E T H:

     WHEREAS,  DRI,  Agent and Banks are parties to that certain First  Restated
Credit  Agreement  dated as of December 29, 1997, as amended by (a) that certain
First Amendment to First Restated Credit Agreement dated as of January 27, 1998,
(b) that certain Second Amendment to First Restated Credit Agreement dated as of
February 25, 1998,  (c) that certain Third  Amendment to First  Restated  Credit
Agreement  dated as of August 10,  1998,  (d) that certain  Fourth  Amendment to
First Restated  Credit  Agreement  dated February 19, 1999, and (e) that certain
Fifth  Amendment to First Restated  Credit  Agreement dated as of April 21, 1999
(as amended, 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 DRI; and

     WHEREAS,  the parties desire to amend Section 9.15 of the Credit  Agreement
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,  DRI,
Agent and each Bank hereby agree as follows:

     Section  1.  Amendment.  Section  9.15 of the  Credit  Agreement  is hereby
amended effective as of the Effective Date to read in full as follows:

     "SECTION 9.15. Qualified Purpose.  Borrower will not request or receive any
Borrowing  hereunder if, after giving effect thereto and the use of the proceeds
thereof,  that portion of the principal  balance of the Revolving  Loan which is
outstanding at such time and was utilized for any purpose other than a Qualified
Purpose  exceeds twenty five percent (25%) of the  Conforming  Borrowing Base in
effect at such time.  Borrower  agrees  that each  Request  for  Borrowing  will
include, in addition to the information described in Section 2.2 hereof, a

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certification  from an  Authorized  Officer of  Borrower  as to the  purpose and
utilization  of the proceeds of such  Borrowing.  Additionally,  notwithstanding
anything to the contrary contained in Section 3.2 hereof, all principal payments
received by Banks with respect to the  Revolving  Loan shall be applied first to
that portion of the outstanding principal balance of the Revolving Loan utilized
for purposes other than Qualified Purposes.  Notwithstanding the foregoing,  the
Credit  Parties  shall not be required to comply with this  Section  9.15 at any
time (a) on or prior to the date Texas Pacific  Group makes the Proposed  Equity
Contribution  (and Parent,  in turn,  contributes  the proceeds of such Proposed
Equity Contribution to the common equity capital of Borrower),  and (b) that the
Borrowing  Base  is  equal  to the  Conforming  Borrowing  Base.  Any  principal
outstanding  under the Revolving Loan immediately after giving effect to receipt
and application of the proceeds of the Proposed Equity Contribution (as required
pursuant  to  Section  2.6)  shall be  deemed  to be  utilized  for a  Qualified
Purpose."

      Section 2.  Miscellaneous.

     2.1  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.  DRI hereby
extends the Liens securing the Obligations  until the Obligations have been paid
in full or are  specifically  released  by Agent and Banks  prior  thereto,  and
agrees that the amendments and modifications herein contained shall in no manner
adversely  affect or impair the  Obligations or the Liens  securing  payment and
performance thereof.

     2.2  Parties in  Interest.  All of the terms and  provisions  of this Sixth
Amendment  shall bind and inure to the benefit of the  parties  hereto and their
respective successors and assigns.

     2.3 Legal Expenses.  DRI hereby agrees to pay on demand all reasonable fees
and  expenses of counsel to Agent  incurred  by Agent,  in  connection  with the
preparation,  negotiation  and execution of this Sixth Amendment and all related
documents.

     2.4 Counterparts. This Sixth Amendment may be executed in counterparts, and
all parties need not execute the same  counterpart;  however,  no party shall be
bound by this Sixth  Amendment  until all parties have  executed a  counterpart.
Facsimiles shall be effective as originals.

     2.5 Complete Agreement.  THIS SIXTH 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 AMONG THE PARTIES.



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

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


                                             BORROWER:

                                             DENBURY RESOURCES, INC.,
                                             a Delaware corporation


                                             By:
                                                --------------------------------
                                                       Gareth Roberts
                                                  President and Chief Executive
                                                          Officer


                                             By:
                                                --------------------------------
                                                        Phil Rykhoek
                                                 Chief Financial Officer and
                                                          Secretary


                                             ADMINISTRATIVE AGENT:

                                             BANK OF AMERICA, N.A.,


                                             By:
                                               ---------------------------------
                                                    J. Scott Fowler,
                                                   Managing Director


                                             BANKS:

                                             BANK OF AMERICA, N.A.,


                                             By:
                                               ---------------------------------
                                                    J. Scott Fowler,
                                                   Managing Director




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                                             BANKBOSTON, N.A.


                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------



                                             BANK ONE, TEXAS, N.A.

                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------


                                             CHASE BANK OF TEXAS, NATIONAL
                                             ASSOCIATION

                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------

                                            CHRISTIANIA BANK, OG KREDITKASSE ASA

                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------


                                             PARIBAS


                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------


                                             CREDIT LYONNAIS - NEW YORK BRANCH

                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------


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                                             WELLS FARGO BANK (TEXAS), N.A.


                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------

                                             NATEXIS BANQUE BFCE

                                             By:
                                               ---------------------------------
                                             Name:
                                               ---------------------------------
                                             Title:
                                               ---------------------------------




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