Document:

<PAGE>

                                                                    EXHIBIT 10.1

                      FIRST AMENDMENT TO CREDIT AGREEMENT

                                 BY AND AMONG

                          ATP OIL & GAS CORPORATION,
                                 AS BORROWER,

                                 BNP PARIBAS,
                           AS ADMINISTRATIVE AGENT,

                                      AND

                         THE LENDERS SIGNATORY HERETO

                         EFFECTIVE AS OF JUNE 29, 2001
<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                 Page
<S>                <C>                                                           <C>
ARTICLE I.         DEFINITIONS................................................      1
 Section 1.01      Terms Defined Above........................................      1
 Section 1.02      Terms Defined in Credit Agreement..........................      1
 Section 1.03      Other Definitional Provisions..............................      1

ARTICLE II.        AMENDMENTS TO CREDIT AGREEMENT.............................      1
 Section 2.01      Amendments and Supplements to Definitions..................      2
 Section 2.02      Amendments to Article II...................................      2
 Section 2.03      Amendments to Article IX...................................      3
 Section 2.04      Amendments to Schedules....................................      3

ARTICLE III.       CONDITIONS.................................................      3
 Section 3.01      Loan Documents.............................................      3
 Section 3.02      Corporate Proceedings of Loan Parties......................      3
 Section 3.03      Representations and Warranties.............................      4
 Section 3.04      No Default.................................................      4
 Section 3.05      No Change..................................................      4
 Section 3.06      Security Instruments.......................................      4
 Section 3.07      Amendment Fee..............................................      4
 Section 3.08      Other Instruments or Documents.............................      4

ARTICLE IV.        MISCELLANEOUS..............................................      4
 Section 4.01      Adoption, Ratification and Confirmation of Credit Agreement      4
 Section 4.02      Successors and Assigns.....................................      4
 Section 4.03      Counterparts...............................................      4
 Section 4.04      Number and Gender..........................................      4
 Section 4.05      Entire Agreement...........................................      5
 Section 4.06      Invalidity.................................................      5
 Section 4.07      Titles of Articles, Sections and Subsections...............      5
 Section 4.08      Governing Law..............................................      5
</TABLE>

                                       i
<PAGE>

                      FIRST AMENDMENT TO CREDIT AGREEMENT

     This FIRST AMENDMENT TO CREDIT AGREEMENT (this "First Amendment") executed
effective as of the 29th day of June, 2001 (the "Effective Date"), is by and
among ATP OIL & GAS CORPORATION, a corporation formed under the laws of the
State of Texas (the "Borrower"); each of the lenders that is a signatory hereto
or which becomes a signatory hereto and to the hereinafter described Credit
Agreement as provided in Section 12.06 of the Credit Agreement (individually,
together with its successors and assigns, a "Lender" and, collectively, the
"Lenders"); and BNP PARIBAS, a financial institution formed under the laws of
France (in its individual capacity, "Paribas"), as agent for the Lenders (in
such capacity, together with its successors in such capacity, the
"Administrative Agent").

                              W I T N E S S E T H:

     WHEREAS, the Borrower, Administrative Agent and Lenders are parties to that
certain Credit Agreement dated as of April 27, 2001 (the "Credit Agreement"),
pursuant to which the Lenders agreed to make loans to and extensions of credit
on behalf of the Borrower; and

     WHEREAS, the Borrower, and the Lenders desire to amend the Credit Agreement
in the particulars hereinafter provided;

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
herein contained, the parties hereto agree as follows:

                            ARTICLE I. DEFINITIONS

     Section 1.01 Terms Defined Above. As used in this First Amendment, each of
the terms "Borrower", "Credit Agreement", "Effective Date", "First Amendment",
and "Lenders" shall have the meaning assigned to such term hereinabove.

     Section 1.02 Terms Defined in Credit Agreement. Each term defined in the
Credit Agreement and used herein without definition shall have the meaning
assigned to such term in the Credit Agreement, unless expressly provided to the
contrary.

     Section 1.03   Other Definitional Provisions.

     (a) The words "hereby", "herein", "hereinafter", "hereof", "hereto" and
"hereunder" when used in this First Amendment shall refer to this First
Amendment as a whole and not to any particular Article, Section, subsection or
provision of this First Amendment.

     (b) Section, subsection and Exhibit references herein are to such Sections,
subsections and Exhibits to this First Amendment unless otherwise specified.

                  ARTICLE II. AMENDMENTS TO CREDIT AGREEMENT

     The Borrower, the Administrative Agent, and the Lenders agree that the
Credit Agreement is hereby amended, effective as of the Effective Date, in the
following particulars.

                                       1
<PAGE>

     Section 2.01   Amendments and Supplements to Definitions.

     (a)  The following term, which is defined in Section 1.02 of the Credit
Agreement, is hereby amended in its entirety to read as follows:

          "Agreement" shall mean this Credit Agreement, as amended and
     supplemented by the First Amendment and as the same may from time to time
     be further amended or supplemented.

     (b)  Section 1.02 of the Credit Agreement is hereby further amended and
supplemented by adding the following new definition  where alphabetically
appropriate, which reads in its entirety as follows:

          "First Amendment" shall mean that certain First Amendment to Credit
     Agreement dated as of June 29, 2001, by and among the Borrower, the
     Administrative Agent and the Lenders.

     Section 2.02   Amendments to Article II.

     (a) Section 8.01 of the Credit Agreement is hereby amended by adding
thereto new subsections (j) and (k) as follows:

          "(j) Monthly Financial Statements.  As soon as available and in any
     event within 25 days after the end of each calendar month, consolidating
     statements of income of the Borrower and its Consolidated Subsidiaries for
     the immediately preceding calendar month, and the related consolidating
     balance sheets as at the end of such period, accompanied by the certificate
     of a Responsible Officer, which certificate shall state that said financial
     statements fairly present the consolidated and consolidating financial
     condition and results of operations of the Borrower and its Consolidated
     Subsidiaries in accordance with GAAP, as at the end of, and for, such
     period (subject to normal year-end audit adjustments).

          (k) Accounts Payable Report.  Within three Business Days after the
     15th and last day of each calendar month, the certificate of a Responsible
     Officer certifying that attached thereto is a true and complete report of
     all accounts payable and other current liabilities of the Borrower and its
     Consolidated Subsidiaries, including aging of all such accounts, as of the
     immediately preceding 15th or last day of the relevant month."

     (b) Section 8.11(a) of the Credit Agreement is hereby amended in its
entirety to read as follows:

          "(a) Promptly after the Closing Date, but in any event on or before
     July 31, 2001, the Borrower shall have caused ATP (UK) to have (i) executed
     and delivered in favor of the Administration Agent fixed and floating
     charges on all of the Oil and Gas Properties of ATP (UK) located in the
     North Sea to secure the Obligations, (ii) taken all action necessary to
     obtain all necessary consents and approvals from all necessary Persons and
     Governmental Authorities and to duly register such fixed and floating
     charges, (iii) obtained and delivered certificates of the appropriate
     Governmental

                                       2
<PAGE>

     Authorities with respect to the existence, qualification and good standing
     (or the functional equivalent under English law) of ATP (UK), and (iv)
     caused to be delivered an opinion from counsel to ATP (UK), in form and
     substance satisfactory to the Administrative Agent, as to such matters
     incident to the transactions herein contemplated relating to ATP (UK) as
     the Administrative Agent may reasonably request."

     Section 2.03 Amendments to Article IX. Section 9.13 of the Credit Agreement
is hereby amended in its entirety to read as follows:

          "Section 9.13  Current Ratio.  The Borrower will not permit its ratio
     of (i) consolidated current assets to (ii) consolidated current liabilities
     (excluding current maturities of the Notes) to be less than (A) 0.85 to
     1.00 at the end of the fiscal quarter of the Borrower ending June 30, 2001
     and (B) 1.00 to 1.00 at the end of any fiscal quarter of the Borrower
     thereafter."

     Section 2.04   Amendments to Schedules.  Schedule 9.03 is hereby amended by
replacing item 2 thereof with the following:

          "2.  Loans from the Borrower to ATP (UK) of not more than $5,000,000
     at any one time outstanding as of the Closing Date and for a period not to
     extend past July 31, 2001."

                            ARTICLE III. CONDITIONS

     The enforceability of this First Amendment against the Administrative Agent
and the Lenders is subject to the satisfaction of the following conditions
precedent:

     Section 3.01 Loan Documents. The Administrative Agent shall have received
multiple original counterparts, as requested by the Administrative Agent, of
this First Amendment executed and delivered by a duly authorized officer of the
Borrower, the Administrative Agent, and each Lender.

     Section 3.02 Corporate Proceedings of Loan Parties. The Administrative
Agent shall have received multiple copies, as requested by the Administrative
Agent, of the resolutions, in form and substance reasonably satisfactory to the
Administrative Agent, of the Board of Directors of the Borrower, authorizing the
execution, delivery and performance of this First Amendment, each such copy
being attached to an original certificate of the Secretary or an Assistant
Secretary of the Borrower, dated as of the Effective Date, certifying (i) that
the resolutions attached thereto are true, correct and complete copies of
resolutions duly adopted by written consent or at a meeting of the Board of
Directors, (ii) that such resolutions constitute all resolutions adopted with
respect to the transactions contemplated hereby, (iii) that such resolutions
have not been amended, modified, revoked or rescinded as of the Effective Date,
(iv) that the articles of incorporation and bylaws of the Borrower have not been
amended or otherwise modified since the effective date of the Credit Agreement,
except pursuant to any amendments attached thereto, and (v) as to the incumbency
and signature of the officers of the Borrower executing this First Amendment.

                                       3
<PAGE>

     Section 3.03   Representations and Warranties.  Except as affected by the
transactions contemplated in the Credit Agreement and this First Amendment, each
of the representations and warranties made by the Borrower in or pursuant to the
Loan Documents shall be true and correct in all material respects as of the
Effective Date, as if made on and as of such date.

     Section 3.04 No Default. No Default or Event of Default shall have occurred
and be continuing as of the Effective Date.

     Section 3.05 No Change. No event shall have occurred since December 31,
2000, which, in the reasonable opinion of the Lenders, could have a Material
Adverse Effect.

     Section 3.06 Security Instruments. All of the Security Instruments shall be
in full force and effect and provide to the Administrative Agent the security
intended thereby to secure the Indebtedness, as amended and supplemented hereby.

     Section 3.07   Amendment Fee.  The Borrower shall have paid to the
Administrative Agent for the benefit of the Lenders an amendment fee of $25,000.

     Section 3.08 Other Instruments or Documents. The Administrative Agent or
any Lender or counsel to the Administrative Agent shall receive such other
instruments or documents as they may reasonably request.

                           ARTICLE IV. MISCELLANEOUS

     Section 4.01   Adoption, Ratification and Confirmation of Credit Agreement.
Each of the Borrower, the Administrative Agent, and the Lenders does hereby
adopt, ratify and confirm the Credit Agreement, as amended hereby, and
acknowledges and agrees that the Credit Agreement, as amended hereby, is and
remains in full force and effect.

     Section 4.02 Successors and Assigns. This First Amendment shall be binding
upon and inure to the benefit of the parties hereto and their respective
successors and assigns permitted pursuant to the Credit Agreement.

     Section 4.03 Counterparts. This First Amendment may be executed by one or
more of the parties hereto in any number of separate counterparts, and all of
such counterparts taken together shall be deemed to constitute one and the same
instrument and shall be enforceable as of the Effective Date upon the execution
of one or more counterparts hereof by the Borrower, the Administrative Agent and
the Lenders. In this regard, each of the parties hereto acknowledges that a
counterpart of this First Amendment containing a set of counterpart execution
pages reflecting the execution of each party hereto shall be sufficient to
reflect the execution of this First Amendment by each necessary party hereto and
shall constitute one instrument.

     Section 4.04   Number and Gender.  Whenever the context requires, reference
herein made to the single number shall be understood to include the plural; and
likewise, the plural shall be understood to include the singular.  Words
denoting sex shall be construed to include the masculine, feminine and neuter,
when such construction is appropriate; and specific enumeration shall not
exclude the general but shall be construed as cumulative.  Definitions of terms
defined

                                       4
<PAGE>

in the singular or plural shall be equally applicable to the plural or singular,
as the case may be, unless otherwise indicated.

     Section 4.05 Entire Agreement. This First Amendment constitutes the entire
agreement among the parties hereto with respect to the subject hereof. All prior
understandings, statements and agreements, whether written or oral, relating to
the subject hereof are superseded by this First Amendment.

     Section 4.06 Invalidity. In the event that any one or more of the
provisions contained in this First Amendment shall for any reason be held
invalid, illegal or unenforceable in any respect, such invalidity, illegality or
unenforceability shall not affect any other provision of this First Amendment.

     Section 4.07   Titles of Articles, Sections and Subsections.  All titles or
headings to Articles, Sections, subsections or other divisions of this First
Amendment or the exhibits hereto, if any, are only for the convenience of the
parties and shall not be construed to have any effect or meaning with respect to
the other content of such Articles, Sections, subsections, other divisions or
exhibits, such other content being controlling as the agreement among the
parties hereto.

     Section 4.08   Governing Law.  This First Amendment shall be deemed to be a
contract made under and shall be governed by and construed in accordance with
the internal laws of the State of Texas.

     THIS FIRST AMENDMENT, THE CREDIT AGREEMENT, AS AMENDED HEREBY, THE NOTES,
     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 NEXT PAGE]

                                       5
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this First Amendment to
be duly executed and delivered by their proper and duly authorized officers as
of the Effective Date.

BORROWER:                           ATP OIL & GAS CORPORATION

                                    By:  /s/ Albert L. Reese, Jr.
                                         ------------------------
                                         Albert L. Reese, Jr.
                                         Sr. Vice President and
                                         Chief Financial Officer

                                      S-1
<PAGE>

LENDER AND ADMINISTRATIVE AGENT:    BNP PARIBAS, individually and
                                    as Administrative Agent

                                    By:  /s/ Brian Malone
                                         --------------------
                                    Name:  Brian Malone
                                    Title: Managing Director

                                    By:  /s/ Betsy Jocher
                                         --------------------
                                    Name:  Betsy Jocher
                                    Title: Vice President

                                      S-2<PAGE>

                                                                    EXHIBIT 10.2

                     SECOND AMENDMENT TO CREDIT AGREEMENT

                                  BY AND AMONG

                           ATP OIL & GAS CORPORATION,
                                  AS BORROWER,

                                  BNP PARIBAS,
                            AS ADMINISTRATIVE AGENT,

                        UNION BANK OF CALIFORNIA, N.A.,
                             AS SYNDICATION AGENT,

                                      AND

                          THE LENDERS SIGNATORY HERETO

                         EFFECTIVE AS OF JUNE 29, 2001
<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                 Page
<S>                <C>                                                           <C>
ARTICLE I          DEFINITIONS................................................      1
 Section 1.01      Terms Defined Above........................................      1
 Section 1.02      Terms Defined in Credit Agreement..........................      1
 Section 1.03      Other Definitional Provisions..............................      1

ARTICLE II         AMENDMENTS TO CREDIT AGREEMENT.............................      2
 Section 2.01      Amendments and Supplements to Definitions..................      2
 Section 2.02      Amendments to Article VIII.................................      2
 Section 2.03      Amendments to Article IX...................................      3
 Section 2.04      Amendments to Article X....................................      3

ARTICLE III        CONDITIONS.................................................      3
 Section 3.01      Loan Documents.............................................      4
 Section 3.02      Corporate Proceedings of Loan Parties......................      4
 Section 3.03      Representations and Warranties.............................      4
 Section 3.04      No Default.................................................      4
 Section 3.05      No Change..................................................      4
 Section 3.06      Security Instruments.......................................      4
 Section 3.07      Mandatory Prepayment.......................................      5
 Section 3.08      Other Instruments or Documents.............................      5

ARTICLE IV         MISCELLANEOUS..............................................      5
 Section 4.01      Adoption, Ratification and Confirmation of Credit Agreement      5
 Section 4.02      Successors and Assigns.....................................      5
 Section 4.03      Redetermination of Borrowing Base..........................      5
 Section 4.04      Counterparts...............................................      5
 Section 4.05      Number and Gender..........................................      5
 Section 4.06      Entire Agreement...........................................      6
 Section 4.07      Invalidity.................................................      6
 Section 4.08      Titles of Articles, Sections and Subsections...............      6
 Section 4.09      Governing Law..............................................      6
</TABLE>

                                       i
<PAGE>

                      SECOND AMENDMENT TO CREDIT AGREEMENT

     This SECOND AMENDMENT TO CREDIT AGREEMENT (this "Second Amendment")
executed effective as of the 29th day of June, 2001 (the "Effective Date"), is
by and among ATP OIL & GAS CORPORATION, a corporation formed under the laws of
the State of Texas (the "Borrower"); each of the lenders that is a signatory
hereto or which becomes a signatory hereto and to the hereinafter described
Credit Agreement as provided in Section 12.06 of the Credit Agreement
(individually, together with its successors and assigns, a "Lender" and,
collectively, the "Lenders"); BNP PARIBAS, a financial institution formed under
the laws of France (in its individual capacity, "Paribas"), as agent for the
Lenders (in such capacity, together with its successors in such capacity, the
"Administrative Agent"); and UNION BANK OF CALIFORNIA, N.A., as syndication
agent.

                              W I T N E S S E T H:

     WHEREAS, the Borrower, Administrative Agent and Lenders are parties to that
certain Credit Agreement dated as of April 27, 2001 as amended and supplemented
by that certain First Amendment to Credit Agreement dated as of June 29, 2001
(the "Credit Agreement"), pursuant to which the Lenders agreed to make loans to
and extensions of credit on behalf of the Borrower; and

     WHEREAS, the Borrower, and the Lenders desire to amend the Credit Agreement
in the particulars hereinafter provided;

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
herein contained, the parties hereto agree as follows:

                                   ARTICLE I

                                  DEFINITIONS

     Section 1.01 Terms Defined Above. As used in this Second Amendment, each of
the terms "Borrower", "Credit Agreement", "Effective Date", "Second Amendment",
and "Lenders" shall have the meaning assigned to such term hereinabove.

     Section 1.02 Terms Defined in Credit Agreement. Each term defined in the
Credit Agreement and used herein without definition shall have the meaning
assigned to such term in the Credit Agreement, unless expressly provided to the
contrary.

     Section 1.03   Other Definitional Provisions.

     (a) The words "hereby", "herein", "hereinafter", "hereof", "hereto" and
"hereunder" when used in this Second Amendment shall refer to this Second
Amendment as a whole and not to any particular Article, Section, subsection or
provision of this Second Amendment.

                                       1
<PAGE>

     (b) Section, subsection and Exhibit references herein are to such Sections,
subsections and Exhibits to this Second Amendment unless otherwise specified.

                                  ARTICLE II

                        AMENDMENTS TO CREDIT AGREEMENT

     The Borrower, the Administrative Agent, and the Lenders agree that the
Credit Agreement is hereby amended, effective as of the Effective Date, in the
following particulars.

     Section 2.01   Amendments and Supplements to Definitions.

     (a) The following term, which is defined in Section 1.02 of the Credit
Agreement, is hereby amended in its entirety to read as follows:

          "Agreement" shall mean this Credit Agreement, as amended and
     supplemented by the First Amendment and the Second Amendment and as the
     same may from time to time be further amended or supplemented.

     (b) Section 1.02 of the Credit Agreement is hereby further amended and
supplemented by adding the following new definitions where alphabetically
appropriate, which read in their entirety as follows:

          "Aquila" shall mean Aquila Energy Capital Corporation, a Delaware
     corporation.

          "Note Purchase Agreement" shall mean that certain Note Purchase
     Agreement dated as of June 29, 2001, by and between the Borrower and Aquila
     pursuant to which the Borrower, in accordance with the provisions thereof,
     owes or may owe to Aquila up to $34,320,000, plus interest, fees and other
     costs due thereunder.

          "Second Amendment" shall mean that certain Second Amendment to Credit
     Agreement dated as of June 29, 2001, by and among the Borrower, the
     Administrative Agent and the Lenders.

          "Subordination Agreement" shall mean that certain Intercreditor and
     Subordination Agreement dated as of June 29, 2001 by and among the
     Borrower, the Administrative Agent, the Lenders and Aquila.

     Section 2.02 Amendments to Article VIII. Section 8.01(c) of the Credit
Agreement is hereby amended in its entirety as follows:

          "(c) Promptly after the Borrower knows (i) that any Default or any
     Material Adverse Effect has occurred or (ii) that any default has occurred
     under the Note Purchase Agreement, a notice of such Default or Material
     Adverse Effect or default under the Note Purchase Agreement, describing the
     same in reasonable detail and the action the Borrower proposes to take with
     respect thereto."

                                       2
<PAGE>

     Section 2.03   Amendments to Article IX.

     (a) Section 9.01 of the Credit Agreement is hereby amended by adding
thereto new subsection (i) as follows:

          "(i) Debt of the Borrower under the Note Purchase Agreement which is
     subordinate to the Obligations pursuant to the Subordination Agreement."

     (b) Section 9.02 of the Credit Agreement is hereby amended by adding
thereto new subsection (f) as follows:

          "(f) Liens subordinate in priority to the Liens securing the
     Obligations securing the payment of the Debt of the Borrower under the Note
     Purchase Agreement."

     (c) Section 9.22 of the Credit Agreement is hereby amended in its entirety
to read as follows:

          "Section 9.22    Note Purchase Agreement.

          (a) Guaranties.  The obligations, liabilities and indebtedness created
     under or evidenced by the Note Purchase Agreement and any other documents
     executed in connection therewith shall not be guaranteed (whether a
     guaranty of payment, collection or otherwise) by any Subsidiary of the
     Borrower, unless such guaranty is subordinate to a guaranty of the
     Obligations in favor of the Administrative Agent pursuant to documentation
     in form and substance satisfactory to the Administrative Agent.

          (b) Payment and Modification.  The Borrower shall not make any
     payments on the obligations, liabilities and indebtedness created under or
     evidenced by the Note Purchase Agreement and any other documents executed
     in connection therewith, except as permitted pursuant to the Subordination
     Agreement.  Further, the Borrower shall not amend, supplement, restate or
     otherwise modify, in any material respect, the Note Purchase Agreement or
     any other document executed in connection therewith without the prior
     written consent of the Majority Lenders."

     Section 2.04 Amendments to Article X. Section 10.01 of the Credit Agreement
is hereby amended by adding thereto new subsection (n) as follows:

          "(n)  an event of default shall occur under the Note Purchase
     Agreement."

                                  ARTICLE III

                                  CONDITIONS

     The enforceability of this Second Amendment against the Administrative
Agent and the Lenders is subject to the satisfaction of the following conditions
precedent:

                                       3
<PAGE>

     Section 3.01 Loan Documents. The Administrative Agent shall have received
multiple original counterparts, as requested by the Administrative Agent, of the
following Loan Documents, executed (and acknowledged where appropriate) and
delivered by a duly authorized officer of the Borrower, the Administrative
Agent, each Lender and Aquila, as appropriate:

     (i)   this Second Amendment;

     (ii)  the Subordination Agreement;

     (iii) a Supplement and Amendment to Mortgage, Deed of Trust, Assignment of
           Production, Security Agreement and Financing Statement;

     (iv)  an Act of Supplement and Amendment to Act of Mortgage, Assignment of
           Production, Security Agreement, Fixture Filing and Financing
           Statement; and

     (v)  a First Amendment to Security Agreement.

     Section 3.02 Corporate Proceedings of Loan Parties. The Administrative
Agent shall have received multiple copies, as requested by the Administrative
Agent, of the resolutions, in form and substance reasonably satisfactory to the
Administrative Agent, of the Board of Directors of the Borrower, authorizing the
execution, delivery and performance of this Second Amendment and the other Loan
Documents referenced in Section 3.01 hereof, each such copy being attached to an
original certificate of the Secretary or an Assistant Secretary of the Borrower,
dated as of the date of execution of this Second Amendment, certifying (i) that
the resolutions attached thereto are true, correct and complete copies of
resolutions duly adopted by written consent or at a meeting of the Board of
Directors, (ii) that such resolutions constitute all resolutions adopted with
respect to the transactions contemplated hereby, (iii) that such resolutions
have not been amended, modified, revoked or rescinded as of the date of
execution of this Second Amendment, (iv) that the articles of incorporation and
bylaws of the Borrower have not been amended or otherwise modified since the
effective date of the Credit Agreement, except pursuant to any amendments
attached thereto, and (v) as to the incumbency and signature of the officers of
the Borrower executing this Second Amendment and the other Loan Documents
referenced in Section 3.01 hereof.

     Section 3.03  Representations and Warranties.  Except as affected by the
transactions contemplated in the Credit Agreement and this Second Amendment,
each of the representations and warranties made by the Borrower in or pursuant
to the Loan Documents shall be true and correct in all material respects as of
the Effective Date, as if made on and as of such date.

     Section 3.04 No Default. No Default or Event of Default shall have occurred
and be continuing as of the Effective Date.

     Section 3.05 No Change. No event shall have occurred since December 31,
2000, which, in the reasonable opinion of the Lenders, could have a Material
Adverse Effect.

     Section 3.06 Security Instruments. All of the Security Instruments shall be
in full force and effect and provide to the Administrative Agent the security
intended thereby to secure the Indebtedness, as amended and supplemented hereby.

                                       4
<PAGE>

     Section 3.07  Mandatory Prepayment.  The Borrower shall have paid to the
Administrative Agent concurrent with the execution of this Second Amendment the
mandatory prepayment of $5,000,000 required by the Borrowing Base
redetermination as set forth in Section 4.03 of this Second Amendment.

     Section 3.08 Other Instruments or Documents. The Administrative Agent or
any Lender or counsel to the Administrative Agent shall receive such other
instruments or documents as they may reasonably request.

                                  ARTICLE IV

                                 MISCELLANEOUS

     Section 4.01 Adoption, Ratification and Confirmation of Credit Agreement.
Each of the Borrower, the Administrative Agent, and the Lenders does hereby
adopt, ratify and confirm the Credit Agreement, as amended hereby, and
acknowledges and agrees that the Credit Agreement, as amended hereby, is and
remains in full force and effect.

     Section 4.02 Successors and Assigns. This Second Amendment shall be binding
upon and inure to the benefit of the parties hereto and their respective
successors and assigns permitted pursuant to the Credit Agreement.

     Section 4.03 Redetermination of Borrowing Base. Effective July 24, 2001,
the Borrowing Base, as redetermined pursuant to Section 2.08(b) of the Credit
Agreement, which shall be considered the redetermination occurring on or around
July 31, 2001, shall be $50,000,000, which Borrowing Base shall remain in effect
until the next Scheduled Redetermination Date to occur on or around October 1,
2001. The Lenders hereby waive payment of the Monthly Reduction Amount due
August 1, 2001 in consideration of, and if, the $5,000,000 mandatory prepayment
pursuant to Section 2.07(b)(ii) of the Credit Agreement required by the
redetermination of the Borrowing Base is paid concurrent with the execution of
this Second Amendment.

     Section 4.04 Counterparts. This Second Amendment may be executed by one or
more of the parties hereto in any number of separate counterparts, and all of
such counterparts taken together shall be deemed to constitute one and the same
instrument and shall be enforceable as of the Effective Date upon the execution
of one or more counterparts hereof by the Borrower, the Administrative Agent and
the Lenders. In this regard, each of the parties hereto acknowledges that a
counterpart of this Second Amendment containing a set of counterpart execution
pages reflecting the execution of each party hereto shall be sufficient to
reflect the execution of this Second Amendment by each necessary party hereto
and shall constitute one instrument.

     Section 4.05  Number and Gender.  Whenever the context requires, reference
herein made to the single number shall be understood to include the plural; and
likewise, the plural shall be understood to include the singular.  Words
denoting sex shall be construed to include the masculine, feminine and neuter,
when such construction is appropriate; and specific enumeration shall not
exclude the general but shall be construed as cumulative.  Definitions of terms
defined

                                       5
<PAGE>

in the singular or plural shall be equally applicable to the plural or singular,
as the case may be, unless otherwise indicated.

     Section 4.06 Entire Agreement. This Second Amendment constitutes the entire
agreement among the parties hereto with respect to the subject hereof. All prior
understandings, statements and agreements, whether written or oral, relating to
the subject hereof are superseded by this Second Amendment.

     Section 4.07 Invalidity. In the event that any one or more of the
provisions contained in this Second Amendment shall for any reason be held
invalid, illegal or unenforceable in any respect, such invalidity, illegality or
unenforceability shall not affect any other provision of this Second Amendment.

     Section 4.08  Titles of Articles, Sections and Subsections.  All titles or
headings to Articles, Sections, subsections or other divisions of this Second
Amendment or the exhibits hereto, if any, are only for the convenience of the
parties and shall not be construed to have any effect or meaning with respect to
the other content of such Articles, Sections, subsections, other divisions or
exhibits, such other content being controlling as the agreement among the
parties hereto.

     Section 4.09  Governing Law.  This Second Amendment shall be deemed to be a
contract made under and shall be governed by and construed in accordance with
the internal laws of the State of Texas.

     THIS SECOND AMENDMENT, THE CREDIT AGREEMENT, AS AMENDED HEREBY, THE NOTES,
     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 NEXT PAGE]

                                       6
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Second Amendment to
be duly executed and delivered by their proper and duly authorized officers as
of the Effective Date.

BORROWER:                           ATP OIL & GAS CORPORATION

                                    By:  /s/ T. Paul Bulmahn
                                       ----------------------------------
                                         T. Paul Bulmahn
                                         President

                                     S-1
<PAGE>

LENDER AND ADMINISTRATIVE           BNP PARIBAS, individually and
AGENT:                              as Administrative Agent

                                    By:  /s/ Betsy Jocher
                                       -------------------------------------
                                    Name:  Betsy Jocher
                                    Title: Vice President

                                    By:  /s/ Larry Robinson
                                       -------------------------------------
                                    Name:  Larry Robinson
                                    Title: Vice President

LENDER AND SYNDICATION              UNION BANK OF CALIFORNIA, N.A.,
AGENT:                              individually and as Syndication Agent

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

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

                                      S-2

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00028-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00028-of-00352.parquet"}]]