Document:

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                                                                    EXHIBIT 10.1

                                Credit Agreement
                            Dated as of March 5, 2001
                               (this "Agreement")

Lender:             Verizon Investments Inc., a Delaware corporation ("Lender").

Borrower:           Genuity Inc., a Delaware corporation ("Borrower").

Facility:           $500,000,000 line of credit (the "Facility").

Commitment Period:  March 8, 2001 to, but not including, May 31, 2001
                    (the "Commitment Period").

Maturity Date:      May 31, 2001 (the "Maturity Date").

Five-Year
Agreement:          All references to the Five-Year Agreement herein
                    shall be deemed to refer to the $2,000,000,000 Five-Year
                    Credit Agreement, dated as of September 5, 2000, as amended
                    on December 6, 2000 and as may be amended from time to time
                    hereafter, among Borrower, the initial lenders named
                    therein, The Chase Manhattan Bank, as administrative agent
                    for said lenders, Chase Securities, Inc., as arranger,
                    Citibank, N.A., as syndication agent, and Credit Suisse
                    First Boston and Deutsche Bank AG, New York and/or Cayman
                    Islands Branches, as co-documentation agents (the "Five-Year
                    Agreement").

Availability:       Borrower shall have the right to borrow from time to time
                    under the Facility during the Commitment Period following
                    three business days notice provided through and subject to
                    the terms of a Notice of Borrowing given by Borrower as
                    hereinafter provided (a "Notice of Borrowing"), in an amount
                    not to be less than $25,000,000 or more than $200,000,000 on
                    any business day. All borrowings shall be repaid in full on
                    or before the Maturity Date.

Use of Proceeds:    The proceeds of any borrowing by Borrower under the Facility
                    shall be available for the general corporate purposes of
                    Borrower.

Notice of
Borrowing:          In writing on the Notice of Borrowing form attached hereto,
                    to be delivered to Lender at least three business days in
                    advance of the requested borrowing.

Term of Borrowing:  At Borrower's option, any period to the extent possible, but
                    not less than five business days and not to extend beyond
                    the Maturity Date (a "Term of Borrowing").

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Interest Rate:      The rate of interest on any borrowing under the
                    Facility will be calculated at London Interbank Offer
                    ("LIBO") rate plus 200 basis points per annum, LIBO being
                    the average (rounded upward, if necessary, to the next 1/16
                    of 1%) of the rates per annum at which JP Morgan Chase, or
                    any successor thereto, is offered deposits in United States
                    dollars as of 11:00 a.m. London time, on the second London
                    business day preceding the first day of the Term of
                    Borrowing, by prime banks in the London interbank market of
                    an amount and for an interest period most similar to the
                    Term of Borrowing, adjusted for applicable reserve
                    requirements.

Increased Costs:    If (i) Lender borrows funds from any source at an interest
                    rate based on the LIBO rate during the Commitment Period in
                    response to or in anticipation of the receipt of a Notice of
                    Borrowing from Borrower, (ii) Lender lends such funds to
                    Borrower through the Facility and (iii) Lender incurs or
                    reasonably anticipates that it will incur costs of a nature
                    generally described in Section 2.11 (a) and (b) of the Five-
                    Year Agreement, then Borrower shall reimburse Lender for any
                    such costs incurred or to be incurred by Lender.

Payments:           Interest is payable on the last day of the applicable
                    interest period in immediately available funds. Interest is
                    to be calculated on the basis of the actual number of days
                    elapsed in a year of 360 days. Notwithstanding the
                    foregoing, principal and all remaining interest due and
                    owing to the maturity of each borrowing shall be due and
                    payable at the maturity of each borrowing. If any payment on
                    any borrowing under the Facility is paid for whatever reason
                    on a date other than the last day of the interest period
                    applicable thereto, Borrower shall, upon demand by Lender,
                    pay to Lender any amounts required to compensate Lender for
                    any additional losses, costs or expenses that Lender incurs
                    or reasonably expects to incur as a result of such payment,
                    including, without limitation, any costs which Lender pays
                    or will be required to pay to any source from which Lender
                    may have previously borrowed funds to lend to Borrower under
                    the Facility.

Evidence of Debt:   The Master Promissory Note attached hereto shall evidence
                    borrowings under the Facility.

Representations     Borrower represents and warrants, as of the first day of
and Warranties      the Commitment Period and on each date that Borrower
                    submits to Lender a Notice of Borrowing, as follows:

                    (a)       Borrower is a corporation duly organized, validly
                              existing and in good standing under the laws of
                              the state of its incorporation.

                    (b)       The execution, delivery and performance by
                              Borrower of this Agreement and the Master
                              Promissory Note, and the consummation of the
                              transactions contemplated hereby, are within
                              Borrower's corporate powers, have been duly
                              authorized by all necessary corporate action, and
                              do not contravene (i) Borrower's charter or
                              by-laws (or other equivalent organizational
                              documents)

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                              or (ii) any law or contractual restriction binding
                              on or affecting Borrower.

                    (c)       No authorization or approval or other action by,
                              and no notice to or filing with, any governmental
                              authority or regulatory body or any other third
                              party is required for the due execution, delivery
                              and performance by Borrower of this Agreement or
                              the Master Promissory Note.

                    (d)       This Agreement and the Master Promissory Note have
                              been duly executed and delivered by Borrower.
                              Assuming that this Agreement has been duly
                              executed and delivered by Lender, this Agreement
                              and the Master Promissory Note are legal, valid
                              and binding obligations of Borrower enforceable
                              against Borrower in accordance with their terms,
                              subject to (i) bankruptcy, insolvency,
                              reorganization, moratorium and other similar laws
                              of general application affecting the rights and
                              remedies of creditors and secured parties and (ii)
                              general principals of equity, regardless of
                              whether applied in proceedings in equity or at
                              law.

                    (e)       The consolidated balance sheet of Borrower and its
                              subsidiaries as at December 31, 2000, and the
                              related consolidated statements of income and cash
                              flows of Borrower and its subsidiaries for the
                              fiscal year then ended fairly present the
                              consolidated financial condition of Borrower and
                              its subsidiaries as at such date and the
                              consolidated results of the operations of Borrower
                              and its subsidiaries for the period ended on such
                              date, all in accordance with generally accepted
                              accounting principles consistently applied, and
                              any report or audit opinion issued on such
                              financial statements by Arthur Andersen LLP shall
                              be in standard form and unqualified.

                    (f)       There is no pending or (to the knowledge of
                              Borrower) threatened action or proceeding
                              affecting Borrower or any of its subsidiaries
                              before any court, governmental agency or
                              arbitrator that purports to affect the legality,
                              validity or enforceability of this Agreement or
                              the Master Promissory Note.

                    (g)       Neither Borrower nor any of its subsidiaries is an
                              investment company, as such term is defined in the
                              Investment Company Act of 1940, as amended.

                    (h)       The Five-Year Agreement remains in full force and
                              effect, is enforceable against Borrower in
                              accordance with its terms, subject to (i)
                              bankruptcy, insolvency, reorganization, moratorium
                              and other similar laws of general application
                              affecting the rights and remedies of creditors and
                              secured parties and (ii) general principles of
                              equity, regardless of whether applied in
                              proceedings in equity or at law; and Borrower is
                              permitted to make additional borrowings thereunder
                              (or would be permitted to make such additional
                              borrowings thereunder but for the fact that
                              Borrower is currently indebted to the lenders
                              thereunder in a principal amount equal to
                              $2,000,000,000).

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Standard Covenants:  The provisions with respect to covenants set forth in
                     Article V of the Five-Year Agreement shall be incorporated
                     by reference herein and shall be deemed for all purposes to
                     apply equally to the Facility; provided, however, that (i)
                     the term "Advance" shall be deemed to apply to any
                     borrowing under the Facility and "Commitment" shall be
                     deemed to apply to the obligation of Lender to Borrower to
                     permit Borrower to borrow funds under the Facility, (ii)
                     the terms "Lender," "Lenders" and "Agent" shall each be
                     deemed to apply to Lender, and (iii) Section 5.01(j) shall
                     not be deemed to apply to the Facility.

Additional
Covenants:           Borrower further covenants that during the Commitment
                     Period:

                    (a)       Borrower shall not make any additional borrowings
                              under the Five-Year Agreement if the principal
                              amount of any borrowings made hereunder plus the
                              principal amount of all borrowings then
                              outstanding under the Five-Year Agreement shall
                              exceed $2,000,000,000 until Borrower shall have
                              received at least $500,000,000 in proceeds from
                              any, or any combination of, the following: (i) the
                              issuance of indebtedness in the public or private
                              capital markets, (ii) borrowings under bank credit
                              facilities (other than through borrowings pursuant
                              to the Five-Year Agreement), or (iii) the sale of
                              capital assets no longer used and useful in
                              Borrower's business as then being conducted;
                              provided, however, that the foregoing covenant
                              shall not be applicable during any period that the
                              ratio of the indebtedness actually incurred by
                              Borrower under the Five-Year Agreement to the
                              indebtedness actually incurred by Borrower under
                              the Facility shall equal or exceed 4:1.

                    (b)       Borrower shall apply all net proceeds received
                              from the issuance of indebtedness in public or
                              private capital markets transactions during the
                              Commitment Period to the repayment of all amounts
                              then borrowed under the Facility until all amounts
                              borrowed under the Facility shall have been repaid
                              in full.

                    (c)       Borrower shall never permit the sum of all amounts
                              borrowed under the Facility plus the aggregate
                              principal amount of all public or private capital
                              market securities issued by Borrower and
                              guaranteed by Lender or any affiliate of Lender to
                              exceed 25% of the aggregate debt financing that
                              Borrower is permitted to incur under the
                              Recapitalization Agreement dated June 22, 2000
                              between Lender and GTE Corporation, as such
                              Recapitalization Agreement may be amended from
                              time to time.

Taxes:              If (i) Lender borrows funds from any source during the
                    Commitment Period in response to or in anticipation of the
                    receipt of a Notice of Borrowing from Borrower, (ii) Lender
                    lends such funds to Borrower through the Facility and (iii)
                    Lender is required to pay, or reasonably anticipates that it
                    will be required to pay, Taxes or Other Taxes of a nature
                    generally described in Section 2.14 of the Five-Year
                    Agreement, then Borrower shall reimburse Lender for any such
                    Taxes or Other Taxes paid or to be paid by Lender.

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Expenses:           Borrower agrees to pay an initial fee of $10,000 and on
                    demand all reasonable out-of-pocket costs and expenses of
                    Lender in connection with the preparation, execution,
                    delivery, administration, modification and amendment of this
                    Agreement, the Master Promissory Note and the other
                    documents to be delivered hereunder, upon presentation of an
                    itemized statement of account (after reasonable time for
                    Borrower to review such statement of account). Borrower
                    further agrees to pay on demand all costs and expenses of
                    Lender (including, without limitation, reasonable counsel
                    fees and expenses), in connection with the enforcement
                    (whether through negotiations, legal proceedings or
                    otherwise) of this Agreement, the Master Promissory Note and
                    the other documents to be delivered hereunder, including,
                    without limitation, reasonable fees and expenses of counsel
                    for Lender in connection with the enforcement of rights
                    hereunder.

Indemnification:    Borrower agrees to indemnify and hold harmless Lender and
                    each of their affiliates and their officers, directors,
                    employees, agents and advisors (each, an "Indemnified
                    Party") from and against any and all claims, damages,
                    losses, liabilities and expenses (including, without
                    limitation, reasonable fees and expenses of counsel) that
                    may be incurred by or asserted or awarded against any
                    Indemnified Party, in each case arising out of or in
                    connection with or by reason of, or in connection with the
                    preparation for a defense of, any investigation, litigation
                    or proceeding arising out of, related to or in connection
                    with this Agreement, the Master Promissory Note, any of the
                    transactions contemplated herein or the actual or proposed
                    use any borrowings hereunder, whether or not such
                    investigation, litigation or proceeding is brought by
                    Borrower, its directors, shareholders or creditors or an
                    Indemnified Party or any other Person or any Indemnified
                    Party is otherwise a party thereto, except to the extent
                    such claim, damage, loss, liability or expense (i) results
                    from such Indemnified Party's gross negligence or willful
                    misconduct, or (ii) arises from litigation commenced by
                    Borrower against Lender which seeks enforcement of any of
                    the rights of Borrower hereunder or under the Master
                    Promissory Note and is determined adversely to Lender.
                    Borrower also agrees not to assert any claim against Lender,
                    any of its affiliates, or any of their respective directors,
                    officers, employees, attorneys and agents, on any theory of
                    liability, for special, indirect, consequential or punitive
                    damages arising out of or otherwise relating to this
                    Agreement, the Master Promissory Note, any of the
                    transactions contemplated herein or the actual or proposed
                    use of the any borrowings hereunder. Without prejudice to
                    the survival of any other agreement of Borrower hereunder,
                    the agreements and obligations of Borrower contained in this
                    Indemnification section shall survive the payment in full of
                    principal, interest and all other amounts payable and under
                    the Master Promissory Note.

Events of Default:  In the event (each an "Event of Default") that:

                    (a)       Borrower shall fail to pay any principal of the
                              Master Promissory Note when due; or

                    (b)       Borrower shall fail to pay any interest on the
                              Master Promissory Note, or any facility fee,
                              administration fee or other amounts hereunder,
                              when due, and such amounts remain unpaid for a
                              period of five business days; or

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                    (c)       any representation or warranty made or deemed made
                              by Borrower herein or by Borrower (or any of its
                              officers) in connection with this Agreement shall
                              prove to have been incorrect in any material
                              respect when made or deemed made; or

                    (d)       Borrower shall fail to perform or observe any
                              term, covenant or agreement contained in or
                              incorporated by reference into this Agreement on
                              its part to be performed or observed if such
                              failure shall remain unremedied for 30 days after
                              written notice thereof shall have been given to
                              Borrower by Lender; or

                    (e)       Borrower shall commence a voluntary case or
                              proceeding seeking liquidation, reorganization or
                              other relief with respect to itself or its debts
                              under any bankruptcy, insolvency or other similar
                              law now or hereafter in effect or seeking the
                              appointment of a trustee, receiver, liquidation,
                              custodian or other similar official of its or any
                              substantial part of its property, or shall consent
                              to any such relief or to the appointment of or
                              taking possession by any such official in an
                              involuntary case or other proceeding commenced
                              against it, or shall make a general assignment of
                              the benefit of creditors, or shall fail generally
                              to pay its debts as they become due, or shall take
                              any corporate action to authorize any of the
                              foregoing; or

                    (f)       An involuntary case or other proceeding shall be
                              commenced against Borrower seeking liquidation,
                              reorganization or other relief with respect to it
                              or its debts under any bankruptcy, insolvency or
                              other similar law now or hereafter in effect or
                              seeking the appointment of a trustee, receiver,
                              liquidation, custodian or other similar official
                              or it or a substantial part of its property, and
                              such involuntary case or other proceedings shall
                              remain undismissed and unstayed for a period of 60
                              days or an order for relief shall be entered
                              against Borrower under the federal bankruptcy laws
                              as now or hereafter in effect; or

                    (g)       An event of default (as such term is used in the
                              Five- Year Agreement) shall have occurred and be
                              continuing under the Five-Year Agreement;

                    (h)       (i) Verizon shall cease, prior to the exercise of
                              the option by Verizon Communications Inc.
                              ("Verizon") to exchange its Class B Common Stock
                              of Borrower for Class C Common Stock of Borrower
                              (the "Verizon Option"), to control, directly or
                              indirectly, a sufficient number of shares of
                              Borrower's capital stock such that, upon exercise
                              of the Verizon Option, Verizon would own, directly
                              or indirectly, at least 50% of the combined voting
                              power of all Voting Stock of Borrower; or (ii) the
                              Verizon Option is cancelled or becomes invalid or
                              unenforceable (other than upon the exercise
                              thereof) or the U.S. Federal Communications
                              Commission issues a final ruling that will prevent
                              the exercise of the Verizon Option; or (iii) after
                              the exercise of the Verizon Option, Verizon shall
                              cease to own, directly or indirectly, at least 50%
                              of the combined voting power of all Voting Stock
                              of Borrower;

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                              then, and in every such event, (i) in the case of
                              any of the events specified in paragraphs (e) or
                              (f) above, the Facility shall thereupon
                              automatically be terminated and any outstanding
                              principal and accrued interest on any borrowings
                              hereunder shall automatically become due and
                              payable without presentment, demand, protest or
                              other notice or formality of any kind, all of
                              which are hereby expressly waived, and (ii) in the
                              case of any event specified in paragraphs (a),
                              (b), (c) (d), (g) or (h) above, Lender may, by
                              notice in writing to Borrower, terminate the
                              Facility hereunder, if still in existence, and it
                              shall thereupon be terminated, and Lender may, by
                              notice in writing to Borrower, declare any
                              outstanding principal and accrued interest on any
                              borrowing hereunder to be, and the same shall
                              thereupon forthwith become, due and payable
                              without presentment, demand, protest or other
                              notice of formality of any kind, all of which are
                              hereby expressly waived.

Conditions:                   The obligation of Lender to make loans in
                              accordance with the terms of the Facility is
                              subject to the conditions precedent that: (i) the
                              representations and warranties made herein shall
                              be true on the date of each borrowing (and
                              Borrower's acceptance of the proceeds of such
                              borrowing shall constitute Borrower's
                              representation that the representations and
                              warranties contained in this Agreement are true on
                              the date of such loan) and (ii) no event which,
                              with the giving of notice or passage of time, or
                              both, would constitute an Event of Default has
                              occurred and is continuing.

Defined Terms:                All terms used and not otherwise defined
                              herein shall have the meanings ascribed to such
                              terms in the Five-Year Agreement, in each case as
                              in effect on the date hereof and as may be amended
                              from time to time hereafter.

Documentation:                Prior to or concurrently with the first
                              Notice of Borrowing delivered by Borrower to
                              Lender hereunder, Borrower will provide copies of
                              borrowing resolutions adopted by the Board of
                              Directors of Borrower and signature certificates
                              of authorized officers of Borrower to Lender with
                              respect to the Facility in form reasonably
                              satisfactory to Lender. Prior to the initial
                              borrowing under the Facility, Borrower will
                              provide appropriate opinions of counsel
                              substantially in the forms set forth in Exhibit E
                              of the Five-Year Agreement.

Jurisdiction:                 Each of the parties hereto hereby irrevocably
                              and unconditionally submits, for itself and its
                              property, to the nonexclusive jurisdiction of any
                              New York State court or federal court of the
                              United States of America sitting in New York City,
                              and any appellate court from any thereof, in any
                              action or proceeding arising out of or relating to
                              this Agreement or the Master Promissory Note, or
                              for recognition or enforcement of any judgment,
                              and each of the parties hereto hereby irrevocably
                              and unconditionally agrees that all claims in
                              respect of any such action or proceeding may be
                              heard and determined in any such New York State
                              court or, to the extent permitted by law, in such
                              federal court. Each of the parties hereto agrees
                              that a final judgment in any such action or
                              proceeding shall be conclusive and may be enforced
                              in other jurisdictions by suit on the judgment or
                              in any other manner provided by law. Nothing in
                              this Agreement shall affect any right that any
                              party may otherwise have to bring any action or
                              proceeding relating

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                              to this Agreement or the Master Promissory Note in
                              the courts of any jurisdiction.

Venue:                        Each of the parties hereto irrevocably and
                              unconditionally waives, to the fullest extent it
                              may legally and effectively do so, any objection
                              that it may now or hereafter have to the laying of
                              venue of any suit, action or proceeding arising
                              out of or relating to this Agreement or the Master
                              Promissory Note in any New York State or federal
                              court. Each of the parties hereto hereby
                              irrevocably waives, to the fullest extent
                              permitted by law, the defense of an inconvenient
                              forum to the maintenance of such action or
                              proceeding in any such court.

Waiver of Jury Trial:         Borrower and Lender hereby irrevocably waive all
                              right to trial by jury in any action, proceeding
                              or counterclaim (whether based on contract, tort
                              or otherwise) arising out of or relating to this
                              Agreement or the Master Promissory Note or the
                              actions of Lender in the negotiation,
                              administration, performance or enforcement
                              thereof.

Substitution of Lender:       Lender shall have the right to assign and transfer
                              its rights, privileges and obligations hereunder
                              to any corporate affiliate of Lender which has the
                              financial capacity to serve as Lender hereunder
                              ("New Lender") without the consent of Borrower,
                              and following such assignment, (a) New Lender
                              shall be deemed for all purposes hereunder to be
                              Lender hereunder, as if New Lender had served as
                              Lender hereunder as of the first day of the
                              Commitment Period, and (b) the corporation
                              previously serving as Lender hereunder shall be no
                              longer for any purpose hereunder be deemed to be
                              Lender hereunder.

Successors and Assigns:       This Agreement shall inure to the parties hereto
                              and their respective successors and assigns.

Governing Law:                New York.

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     In witness whereof, the parties hereto have caused this Agreement to be
executed by their respective officers thereunto duly authorized, as of the date
first above written.

                  GENUITY INC.

                  By:   /s/ W. Jack Reagan
                       --------------------------
                  Name:  W. Jack Reagan
                  Title:    Vice President and Treasurer

                  VERIZON INVESTMENTS INC.

                  By:   /s/ Janet M. Garrity
                       --------------------------
                  Name:  Janet M. Garrity
                  Title:  President and Treasurer

                                                                               9<PAGE>

                                                                  Exhibit 10.1.5

                           FOURTH AMENDMENT TO SECOND
                     AMENDED AND RESTATED CREDIT AGREEMENT
                     -------------------------------------

     This Fourth Amendment to Second Amended and Restated Credit Agreement (this
"Fourth Amendment") is entered into effective as of the Effective Date (as
 ----------------
hereinafter defined), by and among Patina Oil & Gas Corporation, a Delaware
corporation ("Borrower"), The Chase Manhattan Bank, successor by merger to Chase
              --------
Bank of Texas, National Association, as Administrative Agent ("Administrative
                                                               --------------
Agent"), and the financial institutions parties hereto as Banks (individually a
-----
"Bank" and collectively "Banks").
 ----                    -----

                               W I T N E S E T H:
                               ------------------

     WHEREAS, Borrower, Administrative Agent and Banks are parties to that
certain Second Amended and Restated Credit Agreement dated as of July 15, 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, Banks have made a revolving
credit loan to Borrower; and

     WHEREAS, Borrower has requested that Banks (i) amend certain terms of the
Credit Agreement in certain respects, (ii) consent to certain transactions more
particularly described herein, and (iii) establish a Borrowing Base of
$200,000,000 to be effective as of November 1, 2000 and continuing until the
next Determination thereafter; and

     WHEREAS, subject to the terms and conditions herein contained, Banks have
agreed to Borrower's requests.

     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,
Borrower, Administrative Agent and each Bank hereby agree as follows:

     SECTION 1.  Amendments.  In reliance on the representations, warranties,
     ----------  ----------
covenants and agreements contained in this Fourth Amendment, and subject to the
terms and conditions set forth herein, the Credit Agreement is hereby amended
effective as of November 22, 2000 (which date shall be referred to herein as the
"Effective Date") in the manner provided in this Section 1.
 --------------                                  ---------

     1.1. Amendment to Definitions.  The definitions of "Administrative Agent,"
          ------------------------                       --------------------
"Chase," "Loan Papers" and "Permitted Investments" contained in Section 2.1 of
 -----    -----------       ---------------------
the Credit Agreement are amended to read in full as follows:

     "Administrative Agent" means The Chase Manhattan Bank, successor-by-merger
      --------------------
to Chase Bank of Texas, National Association, in its capacity as Administrative
Agent for Banks hereunder or any successor thereto.

                                       1
<PAGE>

     "Chase" means The Chase Manhattan Bank, successor-by-merger to Chase Bank
      -----
of Texas, National Association, in its capacity as a Bank.

     "Loan Papers" means this Agreement, the First Amendment, the Second
      -----------
Amendment, the Third Amendment, the Fourth Amendment, the Notes, each Restricted
Subsidiary Guarantee now or hereafter executed, each Restricted Subsidiary
Pledge Agreement now or hereafter executed, all Mortgages now or at any time
hereafter delivered pursuant to Section 6.1, the Collateral Assignment, the
                                -----------
Collateral Assignment of Loan, and all other certificates, documents or
instruments delivered in connection with this Agreement, as the foregoing may be
amended from time to time.

     "Permitted Investment" means, with respect to Borrower or any Restricted
      --------------------
Subsidiary, (a) readily marketable direct obligations of the United States of
America, (b) fully insured time deposits and certificates of deposit with
maturities of one (1) year or less of any commercial bank operating in the
United States having capital and surplus in excess of $50,000,000.00, (c)
commercial paper of a domestic issuer if at the time of purchase such paper is
rated in one of the two highest ratings categories of Standard and Poor's
Corporation or Moody's Investors Service, (d) any reverse repurchase agreement
entered into with a commercial bank meeting the criteria described in clause (b)
preceding which is secured by a fully-perfected security interest in a security
of the type described in clauses (a) through (c) preceding and which security
has a market value at the time such reverse repurchase agreement is entered into
of not less than 100% of the obligation of such commercial bank under such
reverse repurchase agreement, (e) Investments by Borrower and its Restricted
Subsidiaries in Borrower or Restricted Subsidiaries of Borrower, (f) Investments
outstanding as of the Closing Date described on Schedule 2 hereof, (g) the
Elysium Equity Investment, (h) the Elysium Loan (provided that the Investments
described in clause (g) and this clause (h) do not exceed an aggregate amount
greater than $81,000,000), and (i) Investments by Borrower and its Restricted
Subsidiaries which when made, together with all other Investments made pursuant
to this clause (i) do not exceed an amount (measured at cost) greater than five
percent (5%) of the Borrowing Base then in effect.

     1.2. Additional Definitions.  Section 2.1 of the Credit Agreement shall be
          ----------------------
amended to add the following definitions to such Section:

     "Collateral Assignment of Loan" means that certain Collateral Assignment of
      -----------------------------
Loan and Security Therefor to be entered into among Elysium, Borrower and
Administrative Agent, in form and substance acceptable to Administrative Agent,
pursuant to which all of Borrower's right, title and interest in and to the
Elysium Credit Agreement, the Elysium Note, and the Elysium Loan Documents, and
all Liens serving the Elysium Loan, shall be assigned to Administrative Agent
for the ratable benefit of Banks to secure the Obligations.

     "Elysium" means Elysium Energy, L.L.C., a New York limited liability
      -------
company.

                                       2
<PAGE>

     "Elysium Credit Agreement" means that certain Credit Agreement dated as of
      ------------------------
November 28, 2000, by and between Borrower and Elysium, pursuant to which
Borrower agreed to provide a credit facility to Elysium in the maximum original
principal amount of $60,000,000.

     "Elysium Equity Investment" means the investment by Borrower of an amount
      -------------------------
not greater than $21,000,000 to purchase fifty percent (50%) of the ownership
interests of Elysium.

     "Elysium Equity Investment Documents" means all agreements, conveyances,
      -----------------------------------
certificates and other documents and instruments now or hereafter executed and
delivered by or between Borrower and Elysium in connection with the Elysium
Equity Investment Transactions.

     "Elysium Equity Investment Transactions" means the transactions to occur
      --------------------------------------
pursuant to the Elysium Equity Investment Documents, including, without
limitation, the completion of the Elysium Equity Investment.

     "Elysium Loan" means the revolving credit loan evidenced by the Elysium
      ------------
Credit Agreement and the Elysium Note which shall in no event exceed a maximum
principal amount of $60,000,000.

     "Elysium Loan Documents" means the Elysium Credit Agreement, the Elysium
      ----------------------
Note and all other "Loan Papers" as defined in the Elysium Credit Agreement, as
the foregoing may be amended from time to time to the extent permitted
hereunder.

     "Elysium Note" means that certain Non-Recourse Note dated November 28,
      ------------
2000, executed by Elysium and payable to Borrower in the original principal
amount of $60,000,000.

     "Fourth Amendment" means the Fourth Amendment to Second Amended and
      ----------------
Restated Credit Agreement dated as of November 22, 2000, entered into by and
among Borrower, Administrative Agent and Banks.

     1.3. Amendment to Material Documents.  Section 10.6 of the Credit Agreement
is amended to read in full as follows:

     "SECTION 10.6. Amendment to Material Documents.  Borrower will not, nor
                    -------------------------------
will Borrower permit any of its Restricted Subsidiaries to, enter into any
material modification or amendment of, grant any material consent under, or
waive any material right or obligation of any Person under (a) its certificate
or articles of incorporation, bylaws, partnership agreement, regulations or
other organizational documents, or (b) any Elysium Loan Document."

     SECTION 2.     Consent and Waiver.  Borrower has requested that Banks (i)
     ----------     ------------------
consent to (a) the Elysium Equity Investment Transactions, and (b) the making by
Borrower of the Elysium Loan (as all such terms in clauses (a) and (b) are
defined in the Credit Agreement as amended by

                                       3
<PAGE>

this Fourth Amendment), and (ii) waive any provision of the Credit Agreement and
the other Loan Papers which prohibit such transactions.

     In reliance on the representations, warranties, covenants and agreements
contained in the Credit Agreement and this Fourth Amendment, and subject to the
satisfaction of the conditions precedent set forth in Section 4 hereof, Banks
                                                      ---------
hereby (A) consent to (i) the Elysium Equity Investment Transactions, and (ii)
the making by Borrower of the Elysium Loan, and (B) waive any provision of the
Credit Agreement and the other Loan Papers which prohibits any such Elysium
Equity Investment Transaction or the making of such Elysium Loan by Borrower.

     The consents and waivers herein contained in this Section 2 are limited
                                                       ---------
solely to (i) the Elysium Equity Investment Transactions, (ii) the making by
Borrower  of the Elysium Loan, and (iii) the applicable provisions of the Credit
Agreement which prohibit such transactions.  Nothing contained herein shall be
deemed (a) a consent to any action other than the Elysium Equity Investment
Transactions and the making of the Elysium Loan, or (b) a waiver of any
provision of the Credit Agreement or any other Loan Papers except to the extent
such provision prohibits any such Elysium Equity Investment Transaction or the
making of the Elysium Loan.

     SECTION 3.     Borrowing Base.  Borrower, Administrative Agent and each
     ---------      --------------
Bank agree that the Borrowing Base in effect for the period from and after
November 1, 2000 until the next Determination thereafter shall be $200,000,000.
Borrower, Administrative Agent and each Bank agree that the Determination
provided for in this Section 3 shall not be construed to be a Special
                     ---------
Determination for purposes of Section 5.3 of the Credit Agreement.

     SECTION 4.     Conditions Precedent.  The effectiveness of (a) the
     ----------     --------------------
amendments to the Credit Agreement contained in Section 1 hereof, (b) the
                                                ---------
consents and waivers contained in Section 2 hereof, and (c) the increase in the
                                  ---------
Borrowing Base contained in Section 3 hereof is subject to the satisfaction of
                            ---------
each of the following conditions precedent.

     4.1. Closing Deliveries  Administrative Agent shall have received each of
          ------------------
the following documents, instruments and agreements, each of which shall be in
form and substance and executed in such counterparts as shall be acceptable to
Administrative Agent and each Bank:

          (a)  on or prior to December 15, 2000, the Collateral Assignment of
          Loan duly executed and delivered by Borrower and Elysium, together
          with such other assignments, conveyances, amendments, agreements and
          other writings including, without limitation, UCC-1 financing
          statements, in form and substance satisfactory to Administrative
          Agent;

          (b)  a copy of the articles or certificate of incorporation,
          certificate of limited partnership, articles of organization or
          comparable charter documents, and all amendments thereto, of each
          Company accompanied by a certificate that such copy is true, correct
          and complete, and dated within ten (10) days of the Effective Date (or
          within such other period as acceptable to Administrative Agent),
          issued by the appropriate governmental authority of the jurisdiction
          of incorporation or organization of each Company, and accompanied by a
          certificate of the Secretary

                                       4
<PAGE>

          or comparable Authorized Officer of each Company that such copy is
          true, correct and complete on the Effective Date;

          (c)  a copy of the bylaws, partnership agreement, regulations,
          operating agreement or comparable charter documents, and all
          amendments thereto, of each Company accompanied by a certificate of
          the Secretary or comparable Authorized Officer of each Company that
          such copy is true, correct and complete as of the Effective Date;

          (d)  certain certificates and other documents issued by the
          appropriate governmental authorities of such jurisdictions as
          Administrative Agent has requested relating to the existence of each
          Company and to the effect that each Company is in good standing with
          respect to the payment of franchise and similar Taxes and is duly
          qualified to transact business in such jurisdictions;

          (e)  a certificate of incumbency of all officers of each Company who
          will be authorized to execute or attest to any Loan Paper, dated the
          Effective Date;

          (f)  copies of resolutions or comparable authorizations approving the
          Loan Papers and authorizing the transactions contemplated by this
          Fourth Amendment and the other Loan Papers, duly adopted by the Board
          of Directors or comparable authority of each Company accompanied by
          certificates of the Secretary or comparable officer of each Company
          that such copies are true and correct copies of resolutions duly
          adopted at a meeting of or (if permitted by applicable law and, if
          required by such law, by the bylaws or other charter documents of such
          Company) by the unanimous written consent of the Board of Directors of
          each Company, and that such resolutions constitute all the resolutions
          adopted with respect to such transactions, have not been amended,
          modified, or revoked in any respect, and are in full force and effect
          as of the Effective Date;

          (g)  an opinion of counsel for Borrower, dated the Effective Date,
          favorably opining as to the enforceability of this Fourth Amendment
          and each of the other Loan Papers and otherwise in form and substance
          satisfactory to Administrative Agent;

          (h)  a certificate signed by an Authorized Officer of Borrower stating
          that (after giving effect to this Fourth Amendment, the Elysium Equity
          Investment Transactions and the making of the Elysium Loan), (i) the
          representations and warranties contained in this Fourth Amendment and
          the other Loan Papers are true and correct in all respects, (ii) no
          Default of Event of Default has occurred and is continuing, and (iii)
          all conditions set forth in Section 7.1 and Section 7.2 of the Credit
          Agreement have been satisfied;

          (i)  on or prior to December 1, 2000, a copy of each of the Elysium
          Equity Investment Documents and the Elysium Loan Documents accompanied
          by a certificate executed by an Authorized Officer of Borrower
          certifying that (i) such copies are accurate and complete and
          represent the complete understanding and

                                       5
<PAGE>

          agreement of the parties thereto, (ii) no material right or obligation
          of any party thereto has been modified, amended or waived, and (iii)
          subject only to funding of a Borrowing to be made under the Credit
          Agreement, the Elysium Equity Investment Transactions and the making
          of the Elysium Loan have been (or will be) consummated on the terms
          set forth in the Elysium Equity Investment Documents and the Elysium
          Loan Documents; and

          (j) such other documents, instruments, agreements and actions as may
          reasonably be required by Administrative Agent and any Bank.

     4.2. Closing Transactions.  Subject only to disbursement and application
          --------------------
of a Borrowing, the Elysium Equity Investment Transactions and the making of the
Elysium Loan shall have occurred (or Administrative Agent shall be satisfied
that such transactions will occur simultaneously therewith).

     4.3. Fees and Expenses.  Borrower shall have paid all reasonable fees and
          -----------------
expenses of counsel to Administrative Agent incurred by Administrative Agent in
connection with the preparation, negotiation and execution of this Fourth
Amendment and all related documents.

     4.4. Other Fees.  Borrower shall have paid to Administrative Agent for
          ----------
the ratable benefit of each Bank, and shall have paid to Administrative Agent
(for its own account), such fees and other amounts as Borrower shall be required
to pay to Administrative Agent pursuant to any separate agreement between
Borrower and Administrative Agent in connection with this Fourth Amendment.

     SECTION 5.  Representations and Warranties of Borrower.  To induce the
     ---------   ------------------------------------------
Banks and Administrative Agent to enter into this Fourth Amendment, Borrower
hereby represents and warrants to Administrative Agent and the Banks as follows:

     5.1. Credit Agreement.  Each representation and warranty of the Companies
          ----------------
contained in the Credit Agreement and the other Loan Papers is true and correct
on the date hereof, and will be true and correct after giving effect to the
Elysium Equity Investment Transactions and the making of the Elysium Loan.

     5.2. Authorization.  The execution, delivery and performance by Borrower of
          -------------
this Fourth Amendment are within Borrower's corporate powers, have been duly
authorized by all necessary corporate action, require no action by or filing
with, any governmental body, agency or official and do not violate or constitute
a default under any provision of applicable law or Material Agreement binding
upon any Company or result in the creation or imposition of any Lien upon any of
the assets of any Company other than the Liens securing the Obligations.

     5.3. Binding Effect.  This Fourth Amendment constitutes the valid and
          --------------
binding obligation of Borrower enforceable in accordance with its terms, except
as (a) the enforceability thereof may be limited by bankruptcy, insolvency or
similar laws affecting creditors rights generally, and (b) the availability of
equitable remedies may be limited by equitable principles of general
application.

                                       6
<PAGE>

     5.4. No Defenses.  Borrower has no defenses to payment, counterclaim or
          -----------
rights of set-off with respect to the Obligations existing on the date hereof.

     SECTION 6.     Miscellaneous;
                    ---------------

     6.1. 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.  Borrower
hereby extends the Liens securing the Obligations until the Obligations have
been paid in full or are specifically released by Administrative 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.

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

     6.3. Legal Expenses.  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 Fourth Amendment and all related documents.

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

     6.5. Complete Agreement.  THIS FOURTH AMENDMENT, THE CREDIT AGREEMENT AND
          ------------------
THE OTHER LOAN PAPERS REPRESENT THE FINAL AGREEMENT AMONG THE PARTIES WITH
RESPECT TO THE SUBJECT MATTER HEREOF AND MAY NOT BE CONTRADICTED BY EVIDENCE OF
PRIOR, CONTEMPORANEOUS OR ORAL AGREEMENTS OF THE PARTIES.  THERE ARE NO
UNWRITTEN ORAL AGREEMENTS BETWEEN OR AMONG THE PARTIES WITH RESPECT TO THE
SUBJECT MATTER HEREOF.

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

     6.7. Release of Lien.   Upon the refinancing in full of the Elysium
          ---------------
Loan, Administrative Agent shall be authorized, without any other action or
consent on the part of any Bank, to execute and deliver releases of the Liens
evidenced by, and granted in connection with, the Collateral Assignment of Loan
and related documents.

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

                            [Signature Pages Follow]

                                       7
<PAGE>

SIGNATURE PAGE  TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                            PATINA OIL & GAS CORPORATION

                            By: /s/  David J. Kornder
                               --------------------------------
                               David J. Kornder, Vice President and Chief
                               Financial Officer

                               [Signature Page]

                                       8
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                                    THE CHASE MANHATTAN BANK, successor-
                                    by-merger to Chase Bank of Texas, National
                                    Association, as Administrative Agent

                                    By:      /s/ Robert C. Mertensotto
                                        ----------------------------------------
                                    Name:    Robert C. Mertensotto
                                         ---------------------------------------
                                    Title:   Managing Director
                                          --------------------------------------

                                    THE CHASE MANHATTAN BANK, successor-
                                    by-merger to Chase Bank of Texas, National
                                    Association, as a Bank

                                    By:      /s/ Robert C. Mertensotto
                                       -----------------------------------------
                                    Name:    Robert C. Mertensotto
                                         ---------------------------------------
                                    Title:   Managing Director
                                          --------------------------------------

                               [Signature Page]
<PAGE>

SIGNATURE PAGE  TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                              BANK OF AMERICA, N.A., as a Bank

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

                               [Signature Page]
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                                        BANK ONE, NA (MAIN OFFICE - CHICAGO),
                                        as a Bank (FORMERLY KNOWN AS THE FIRST
                                        NATIONAL BANK OF CHICAGO)

                                        By:        /s/ Kurt Stoeber
                                           -------------------------------------
                                        Name:      Kurt Stoeber
                                             -----------------------------------
                                        Title:     Corporate Banking Officer
                                              ----------------------------------

                               [Signature Page]
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                              BANKERS TRUST COMPANY, as a Bank

                              By:        /s/ Marcus M. Tarkington
                                 ------------------------------------------
                              Name:      Marcus M. Tarkington
                                   ----------------------------------------
                              Title:     Director
                                    ---------------------------------------

                               [Signature Page]
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                                   CREDIT LYONNAIS NEW YORK BRANCH

                                   By:       /s/ Phillip Spectrum
                                      ------------------------------------------
                                   Name:     Phillip Spectrum
                                        ----------------------------------------
                                   Title:    Senior Vice President
                                         ---------------------------------------

                               [Signature Page]
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                                        FIRST UNION NATIONAL BANK

                                        By:        /s/ Robert R. Wetteroff
                                           -------------------------------------
                                        Name:      Robert R. Wetteroff
                                             -----------------------------------
                                        Title:     Senior Vice President
                                              ----------------------------------

                               [Signature Page]
<PAGE>

SIGNATURE PAGE TO FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT
AGREEMENT, BY AND AMONG PATINA OIL & GAS CORPORATION, AS BORROWER, THE FINANCIAL
INSTITUTIONS PARTIES THERETO, AS BANKS, AND THE CHASE MANHATTAN BANK, AS
ADMINISTRATIVE AGENT.

                                        WELLS FARGO BANK, N.A.

                                        By:      /s/ Todd Stornetta
                                           -------------------------------------
                                        Name:    Todd Stornetta
                                             -----------------------------------
                                        Title:    Vice President
                                              ----------------------------------

                               [Signature Page]

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00021-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00021-of-00352.parquet"}]]