<PAGE>


                                                                 EXHIBIT 10.8(h)

                      FOURTH AMENDMENT TO CREDIT AGREEMENT


         This FOURTH AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is entered
into effective as of December 22, 2000, among WOODWARD MARKETING, L.L.C., a
Delaware limited liability company (the "Borrower"), BANK OF AMERICA, N. A.
("Bank of America"), as a Bank, as an Issuing Bank, and as Agent for the Banks,
BNP PARIBAS, a bank organized under the laws of France ("BNP Paribas"), and
Woodward Marketing, Inc., Atmos Energy Marketing LLC, J. D. Woodward and James
Kifer (collectively the "Guarantors").

         WHEREAS, Borrower and Banks entered into that certain Credit Agreement,
dated to be effective as of August 9, 2000, as amended by that certain First
Amendment to Credit Agreement and Guaranty of Atmos Energy Marketing, LLC dated
as of September 29, 2000, that certain Second Amendment to Credit Agreement
dated as of November 3, 2000, and that certain Third Amendment to Credit
Agreement dated as of December 5, 2000 (as amended the "Credit Agreement"); and

         WHEREAS, the Obligations (as defined in the Credit Agreement) were
guaranteed by the Guarantors pursuant to a Guaranty Agreement executed by each
of the Guarantors, in favor of the Banks, dated as of August 9, 2000 (the
"Guaranty Agreements"); and

         WHEREAS, the Obligations are secured by security interests in the
Collateral (as defined in the Credit Agreement) granted to Bank pursuant to the
Security Agreements (as defined in the Credit Agreement) and pursuant to the
Nations Funds Security Agreement (as defined in the Credit Agreement), each
executed by Borrower (collectively, the "Security Agreements"); and

         WHEREAS, on even date herewith Bank of America has assigned a portion
of its interest under the Credit Agreement to BNP Paribas; and

         WHEREAS, the parties hereto desire to amend the Credit Agreement as set
forth herein.

         NOW, THEREFORE, in consideration of the mutual covenants and agreements
herein contained, Borrower, Bank of America and the Guarantors agree as follows:

         1. The definition of "Adjusted Pro Rata Share" set forth in Section
1.01 of the Credit Agreement, Certain Defined Terms, is deleted in its entirety
and replaced with the following:

                  "Adjusted Pro Rata Share" means, as to any Bank at any
         particular time, the percentage equivalent (expressed as a decimal,
         rounded to the ninth decimal place) at such time of (a) an amount equal
         to such Bank's Uncommitted Line Portion plus, in the case of Bank of
         America, the amount of advances made in excess of the Borrowing Base
         Advance Cap under the Overdraft Line or the Bankcard Line and/or to
         fund Obligations of the Borrower under Swap Contracts or the Bankcard
         Line, and/or to fund overdraft costs arising from of transfers of funds
         made through the automated clearinghouse

<PAGE>


         system, and in the case of BNP Paribas, the amount of advances made in
         excess of the Borrowing Base Advance Cap to fund Obligations of the
         Borrower under Swap Contracts, divided by (b) the combined total of the
         Uncommitted Line of all the Banks plus the amount of advances made in
         excess of the Borrowing Base Advance Cap under the Overdraft Line and
         the Bankcard Line and/or to fund the Obligations of the Borrower under
         the Overdraft Line, the Bankcard Line and/or Swap Contracts, and/or to
         fund overdraft costs arising from of transfers of funds made through
         the automated clearinghouse system, if any.

         2. A new definition, "Bankcard Advance", is added to Section 1.01 of
the Credit Agreement, Certain Defined Terms, to read as follows:

                  "Bankcard Advance" means any advance made hereunder by Bank of
         America under the Bankcard Line.

         3. A new definition, "Bankcard Line", is added to Section 1.01 of the
Credit Agreement, Certain Defined Terms, to read as follows:

                  "Bankcard Line" means that certain discretionary bankcard line
         the Borrower maintains with Bank of America in an amount not to exceed
         $50,000.00.

         4. The definition of "Borrowing Base Advance Cap" set forth in Section
1.01 of the Credit Agreement, Certain Defined Terms, is deleted in its entirety
and replaced with the following:

                  "Borrowing Base Advance Cap" means at any time an amount equal
         to the least of:

                           (a) $125,000,000.00;

                           (b) the Borrowing Base Sub-Cap; or

                           (c) the sum of:

                                    (i) the amount of Cash Collateral and other
                           liquid investments which are acceptable to the Banks
                           in their sole discretion and which are subject to a
                           first perfected security interest in favor of Agent,
                           as collateral agent for the Banks, and which have not
                           been used in determining availability for any other
                           advance (other than advances made under the Borrowing
                           Base Line) or Letter of Credit Issuance; plus

                                    (ii) 90% of Borrower's equity in Banc of
                           America Futures Incorporated accounts, to the extent
                           such equity is not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus


FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 2
<PAGE>


                                    (iii) 90% of Borrower's equity in BNP
                           Paribas Commodity Futures, Inc. accounts from and
                           after the date that a tri-party agreement with
                           respect to such accounts is entered into among
                           Borrower, Agent and BNP Paribas Commodity Futures,
                           Inc., to the extent such equity is not being used in
                           determining availability for any other advance (other
                           than advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus

                                    (iv) 90% of the amount of Tier I Accounts
                           which are not being used in determining availability
                           for any other advance (other than advances made under
                           the Borrowing Base Line) or Letter of Credit
                           Issuance, net of deductions, offsets and
                           counterclaims; plus

                                    (v) 85% of the amount of Tier II Accounts
                           and which are not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance, net of deductions, offsets
                           and counterclaims; plus

                                    (vi) 85% of the amount of Tier I Unbilled
                           Accounts which are not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus

                                    (vii) 80% of the amount of Tier II Unbilled
                           Accounts which are not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus

                                    (viii) 80% of the amount of Eligible
                           Inventory which are not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus

                                    (ix) 80% of the amount of Eligible Exchange
                           Receivables which are not being used in determining
                           availability for any other advance (other than
                           advances made under the Borrowing Base Line) or
                           Letter of Credit Issuance; plus

                                    (x) 80% of the amount of Undelivered Product
                           Value; less

                                    (xi) the amounts which would be subject to a
                           so-called "First Purchaser Lien" as defined in Texas
                           Bus. & Com. Code Section 9.319, comparable laws of
                           the states of Oklahoma, Kansas, Wyoming or New
                           Mexico, or any other comparable law, unless a Letter
                           of Credit secures payment of all amounts subject to
                           such First Purchaser Lien; less

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 3


<PAGE>

                                    (xii) 125% of the mark-to-market amounts
                           owed to Bank of America and/or its Affiliates under
                           Swap Contracts;

                                    (xiii) 125% of the mark-to-market amounts
                           owed to BNP Paribas and/or its Affiliates under Swap
                           Contracts; and

                                    (xiv) 100% of Borrower's Unrealized
                           Mark-to-Market Losses as of the date of determination
                           of Borrowing Base Advance Cap.

                  In no event shall any amounts described in (b)(i) through
         (b)(ix) above which may fall into more than one of such categories be
         counted more than once when making the calculation under of this
         definition.

         5. The definition of "Borrowing Base Sub-Cap" set forth in Section 1.01
of the Credit Agreement, Certain Defined Terms, is deleted in its entirety and
replaced with the following:

                  "Borrowing Base Sub-Cap" means, initially, an amount equal to
         $50,000,000.00; provided, however, Borrower may elect from time to time
         any of $50,000,000.00, $60,000,000.00, $70,000,000.00, $75,000,000.00,
         $80,000,000.00, $90,000,000.00, $100,000,000.00, $110,000,000.00,
         $120,000,000.00 or $125,000,000.00 as the Borrowing Base Sub-cap
         provided that Borrower's Net Working Capital and Tangible Net Worth at
         the time of election are greater than, or equal to, the amounts
         specified below:


                           (a)      If Borrower elects $125,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $25,000,000.00 and Tangible Net Worth
                                    must be at least $26,000,000.00; or

                           (b)      If Borrower elects $120,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $24,000,000.00 and Tangible Net Worth
                                    must be at least $25,000,000.00; or

                           (c)      If Borrower elects $110,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $22,000,000.00 and Tangible Net Worth
                                    must be at least $23,000,000.00; or

                           (d)      If Borrower elects $100,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $20,000,000.00 and Tangible Net Worth
                                    must be at least $21,000,000.00; or

                           (e)      If Borrower elects $95,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $19,000,000.00 and Tangible Net Worth
                                    must be at least $20,000,000.00; or


FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 4
<PAGE>


                           (f)      If Borrower elects $90,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $18,000,000.00 and Tangible Net Worth
                                    must be at least $19,000,000.00; or

                           (g)      If Borrower elects $80,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $16,000,000.00 and Tangible Net Worth
                                    must be at least $17,000,000.00; or

                           (h)      If Borrower elects $75,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $15,000,000.00 and Tangible Net Worth
                                    must be at least $16,000,000.00; or

                           (i)      If Borrower elects $70,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $14,000,000.00 and Tangible Net Worth
                                    must be at least $15,000,000.00; or

                           (j)      If Borrower elects $60,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $12,000,000.00 and Tangible Net Worth
                                    must be at least $13,000,000.00; or

                           (k)      If Borrower elects $50,000,000.00,
                                    Borrower's Net Working Capital must be at
                                    least $10,000,000.00 and Tangible Net Worth
                                    must be at least $11,000,000.00.

                  Borrower shall elect which Borrowing Base Sub-Cap is in effect
         from time to time by delivering to Agent a written notice of such
         election, together with a Compliance Certificate in the form of Exhibit
         C which is attached hereto but modified to include a certification that
         upon the effectiveness of such election, no Default or Event of Default
         will exist.

         6. The definition of "Dollar Advance Cap" set forth in Section 1.01 of
the Credit Agreement, Certain Defined Terms, is deleted in its entirety and
replaced with the following:

                  "Dollar Advance Cap" means a cap upon Revolving Loans under
         the Borrowing Base Line with the following limits:

                  (a)      $50,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $125,000,000.00;

                  (b)      $48,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $120,000,000.00;

                  (c)      $44,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $110,000,000.00; and

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 5

<PAGE>


                  (d)      $40,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $100,000,000.00; and

                  (e)      $38,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $95,000,000.00; and

                  (f)      $36,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $90,000,000.00; and

                  (g)      $32,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $80,000,000.00; and

                  (h)      $30,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $75,000,000.00; and

                  (i)      $28,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $70,000,000.00; and

                  (j)      $24,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $60,000,000.00; and

                  (k)      $20,000,000.00 at such times as the Borrowing Base
                           Sub-Cap is $50,000,000.00.

         7. The definition of "Loan" set forth in Section 1.01 of the Credit
Agreement, Certain Defined Terms, is deleted in its entirety and replaced with
the following:

                  "Loan" means (a) any extension of credit by a Bank to the
         Borrower under Article II or Article III in the form of a Revolving
         Loan or an L/C Advance and (b) any Overdraft Advance or Bankcard
         Advance.

         8. The definition of "Obligations" set forth in Section 1.01 of the
Credit Agreement, Certain Defined Terms, is deleted in its entirety and replaced
with the following:

                                    "Obligations" means all advances, debts,
         liabilities, obligations, covenants and duties arising under any Loan
         Document and any documents related to Bankcard transactions, owing by
         the Borrower to any Bank, or any affiliate of any Bank, the Agent, or
         any Indemnified Person, whether direct or indirect (including those
         acquired by assignment), absolute or contingent, due or to become due,
         now existing or hereafter arising, including without limitation
         overdraft costs arising as a result of transfers of funds made through
         the automated clearinghouse system and all obligations of the Borrower
         under Revolving Loans, Letters of Credit, the Overdraft Line, the
         Bankcard Line and any Swap Contracts.

         9. The definition of "Swap Contract" set forth in Section 1.01 of the
Credit Agreement, Certain Defined Terms, is deleted in its entirety and replaced
with the following:

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 6

<PAGE>


                  "Swap Contract" means any agreement entered into with Bank of
         America or any Affiliate of Bank of America or BNP Paribas or any
         Affiliate of BNP Paribas, whether or not in writing, relating to any
         single transaction that is a rate swap, basis swap, forward rate
         transaction, commodity swap, commodity option, equity or equity index
         swap or option, bond, note or bill option, interest rate option,
         forward foreign exchange transaction, cap, collar or floor transaction,
         currency swap, cross-currency rate swap, currency option or any other
         similar transaction (including any option to enter into any of the
         foregoing) or any combination of the foregoing and, unless the context
         clearly requires, any master agreement relating to or governing any or
         all of the foregoing.

         10. A definition of "Mark to Market" is added to Section 1.01 of the
Credit Agreement, Certain Defined Terms, as follows:

                  "Mark-to-Market" means, the method of accounting used to
         account for derivative commodity instruments entered into for trading
         purposes, in accordance with EITF 98-10, "Accounting for Energy Trading
         and Risk Management Activities" and any future open obligation.

         11. A definition of "Unrealized Mark-to-Market Losses" is added to
Section 1.01 of the Credit Agreement, Certain Defined Terms, as follows:

                  "Unrealized Mark-to-Market Losses" means, Borrower's
         unrealized Mark-to-Market losses as of the day of determination of
         Borrower's Borrowing Base Advance Cap to be reported on a Borrowing
         Base Collateral Position Report, calculated net of unrealized
         Mark-to-Market profits. If a loss, deduct the absolute value of that
         loss, if a profit the value equals zero.

         12. Subsection (c) of Section 2.01 of the Credit Agreement, Procedure
for Borrowing, is hereby deleted in its entirety and replaced with the
following:

                  (c) Advances Related to the Overdraft Line and Swap Contracts.
In addition to advances requested from time to time by the Borrower, in the
event that either (i) any amounts owing to Bank of America or BNP Paribas or any
of their Affiliates under the Overdraft Line or any Swap Contract are not paid
within two (2) Business Days after such obligation arises; or (ii) Bank of
America or any of its Affiliates have made an Overdraft Advance in the amount of
a drawing under a Letter of Credit which has not been timely reimbursed by the
Borrower in accordance with Section 3.03(b) of this Agreement and such amount
has not been paid by the Borrower within one (1) Business Day after such
obligation arises, then Bank of America shall notify the Agent of such failure
to pay and the Agent (without the necessity of any instructions or request from
the Borrower) shall make a Revolving Loan in accordance with the provisions of
Section 2.03 of this Agreement under the Borrowing Base Line for any amounts due
by the Borrower to Bank of America or BNP Paribas or any of their Affiliates
under the Overdraft Line, or any Swap Contract, and then apply the proceeds of
such advance to pay to Bank of America, or BNP Paribas or any of their
Affiliates (as the case may be) all amounts owed to such Person under the
Overdraft Line or such Swap Contract. Upon making any such Revolving Loan, the

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 7

<PAGE>


Agent shall send notice of such Revolving Loan to the Borrower and the Banks.
Any such advance shall initially be a Base Rate Loan. In the event that any such
advance made to fund Bank of America or its Affiliates, other than an advance to
reimburse Bank of America for an Overdraft Advance made to fund a drawing under
Letters of Credit or to fund Reducing L/C Borrowings, results in an advance in
excess of the Borrowing Base Advance Cap, the Banks shall have no duty to fund
their pro rata share of any excess resulting from such advance made to repay
amounts owing to Bank of America or BNP Paribas or any of their Affiliates under
the Overdraft Line or any Swap Contract, but Bank of America or BNP Paribas or
any of their Affiliates', as the case may be, outstandings hereunder shall be
deemed to be increased by the amount of such excess. Notwithstanding the
foregoing, the Banks other than Bank of America shall have the duty, however, to
fund their pro rata share of all Overdraft Advances made to fund drawings under
Letters of Credit or to fund Reducing L/C Borrowings. In the event any advance
described above does exceed the Borrowing Base Advance Cap, the Borrower shall
pay to Agent, for the benefit of Bank of America or its Affiliate (as the case
may be), the amount of such excess, together with interest thereon, within one
(1) Business Day after the date of such advance and, notwithstanding anything to
the contrary herein, the Banks other than Bank of America shall not share in
such payment.

         THE BORROWER ACKNOWLEDGES AND AGREES THAT THE BANKS HAVE ABSOLUTELY NO
DUTY TO FUND ANY REVOLVING LOAN REQUESTED BY THE BORROWER BUT WILL EVALUATE EACH
LOAN REQUEST AND IN EACH BANK'S ABSOLUTE AND SOLE DISCRETION WILL DECIDE WHETHER
TO FUND SUCH LOAN REQUEST. THE BORROWER FURTHER ACKNOWLEDGES AND AGREES THAT
BANK OF AMERICA HAS ABSOLUTELY NO DUTY TO MAKE OR FUND ANY OVERDRAFT ADVANCE OR
TO ENTER INTO ANY SWAP CONTRACT, AND ANY OVERDRAFT ADVANCE OR THE ENTERING INTO
OF ANY SWAP CONTRACT SHALL BE AT BANK OF AMERICA'S ABSOLUTE AND SOLE DISCRETION
AND THAT BNP PARIBAS HAS ABSOLUTELY NO DUTY TO ENTER INTO ANY SWAP CONTRACT, AND
THE ENTERING INTO OF ANY SWAP CONTRACT SHALL BE AT BNP PARIBAS' ABSOLUTE AND
SOLE DISCRETION.

         13. Subsection (a) of Section 2.03 of the Credit Agreement, Procedure
for Borrowing, is hereby deleted in its entirety and replaced with the
following:

                  (a) Each Borrowing of Revolving Loans consisting only of Base
Rate Loans, if approved by the Banks in their sole discretion, shall be made
upon the Borrower's irrevocable written notice delivered to the Agent and the
Banks in the form of a Notice of Borrowing (Revolving Loan), which notice must
be received by the Agent and the Banks prior to 12:00 p.m. (Dallas time) on the
Borrowing Date specifying the amount of the Borrowing. Each such Notice of
Borrowing shall be by electronic transfer or facsimile, confirmed immediately in
an original writing. Each Borrowing of Revolving Loans that includes any
Offshore Rate Loans, if approved by the Banks in their sole discretion, shall be
made upon the Borrower's irrevocable written notice delivered to the Agent and
the Banks in the form of a Notice of Borrowing (which notice must be received by
the Agent and the Banks prior to 12:00 p.m. Dallas time three (3) Business Days
prior to the requested Borrowing Date), specifying the amount of the Borrowing.
Each such Notice of Borrowing shall be by electronic transfer or facsimile,
confirmed

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 8

<PAGE>


immediately in an original writing. Each requested Offshore Rate Loan must have
an Offshore Effective Amount of at least $15,000,000. A Bankcard Advance may be
made by Bank of America in its sole discretion or, at Bank of America's
discretion, upon written request from Borrower.

         14. Section 2.07 of the Credit Agreement, Repayment, is hereby deleted
in its entirety and replaced with the following:

                           2.07 Repayment. The Borrower shall repay the
                  principal amount of each Revolving Loan to the Agent on behalf
                  of the Banks, on the Advance Maturity Date for such Loan. The
                  Borrower shall repay to the Agent for the benefit of Bank of
                  America each Overdraft Advance made under the Overdraft Line
                  and each Bankcard Line Advance made under the Bankcard Line on
                  the next Business Day after such Overdraft Advance or Bankcard
                  Line is made. Notwithstanding anything to the contrary
                  contained herein, the Banks other than Bank of America shall
                  not share in any payment made with respect to the Overdraft
                  Line or the Bankcard Line. All amounts owing Bank of America
                  under the Overdraft Line or the Bankcard Line and all amounts
                  owing to Bank of America or BNP Paribas under any Swap
                  Contract, to the extent such amounts have not been repaid from
                  the proceeds of a Revolving Loan, shall be paid on demand, or
                  if no demand is made, on the first (1st) Business Day after
                  the Borrower receives notice that such amount was advanced by
                  or becomes owing to Bank of America or BNP Paribas.

         15. Subsection (a) and Subsection (b) of Section 2.08 of the Credit
Agreement, Interest, are hereby deleted in their entirety and replaced with the
following:

                  (a) Each Revolving Loan and Overdraft Advance and each
         Bankcard Advance (except for a Revolving Loan made as a result of a
         drawing under a Letter of Credit or a Reducing L/C Borrowing) shall
         bear interest on the outstanding principal amount thereof from the
         applicable Borrowing Date at a floating rate per annum equal to the
         Base Rate plus the Applicable Margin at all times such Loan is a Base
         Rate Loan or at the Offshore Rate plus the Applicable Margin at all
         times such Loan is an Offshore Rate Loan. Each Revolving Loan made as a
         result of a drawing under a Letter of Credit or a Reducing L/C
         Borrowing, all amounts owing to Bank of America or any Affiliate of
         Bank of America under the Overdraft Line or the Bankcard Line or owing
         to Bank of America or BNP Paribas with respect to any Swap Contract,
         shall bear interest on the outstanding principal amount thereof from
         the date funded at a floating rate per annum equal to the Base Rate
         plus the Applicable Margin until such Loan has been outstanding for
         more than two (2) Business Days and, thereafter, shall bear interest on
         the outstanding principal amount thereof at a floating rate per annum
         equal to the Base Rate, plus three percent (3.0%) per annum (the
         "Default Rate").

                  (b) Interest on each Revolving Loan shall be paid upon demand,
         or if no demand is made, shall be paid in arrears on each Interest
         Payment Date. Interest on each Overdraft Advance and each Bankcard
         Advance shall be paid upon demand, or if no

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 9

<PAGE>


         demand is made, on the earlier to occur of the date of repayment of
         such Overdraft Advance or Bankcard Advance or the date such Overdraft
         Advance is due and payable.

         16. Section 2.13 of the Credit Agreement, Sharing of Payments, Etc., is
hereby deleted in its entirety and replaced with the following:

         2.13 Sharing of Payments, Etc. If, other than as expressly provided
elsewhere herein, any Bank shall obtain on account of the Loans made by it any
payment (whether voluntary, involuntary, through the exercise of any right of
set-off, or otherwise) in excess of its Pro Rata Share or Adjusted Pro Rata
Share, as the case may be at such time (other than payments to Bank of America
or BNP Paribas with respect to advances made in excess of the Borrowing Base
Advance Cap as a result of payment under a Swap Contract or advances under the
Overdraft Line or the Bankcard Line), such Bank shall immediately (a) notify the
Agent of such fact, and (b) purchase from the other Banks such participations in
the Loans made by them as shall be necessary to cause such purchasing Bank to
share the excess payment pro rata with each of them; provided, however, that if
all or any portion of such excess payment is thereafter recovered from the
purchasing Bank, such purchase shall to that extent be rescinded and each other
Bank shall repay to the purchasing Bank the purchase price paid therefor,
together with an amount equal to such paying Bank's ratable share (according to
the proportion of (i) the amount of such paying Bank's required repayment to
(ii) the total amount so recovered from the purchasing Bank) of any interest or
other amount paid or payable by the purchasing Bank in respect of the total
amount so recovered. The Borrower agrees that any Bank so purchasing a
participation from another Bank may, to the fullest extent permitted by law,
exercise all its rights of payment (including the right of set-off, but subject
to Section 11.09) with respect to such participation as fully as if such Bank
were the direct creditor of the Borrower in the amount of such participation.
The Agent will keep records (which shall be conclusive and binding in the
absence of manifest error) of participations purchased under this Section and
will in each case notify the Banks following any such purchases or repayments.

         17. Section 2.14 of the Credit Agreement, The Election of One Bank to
Continue Funding, is hereby deleted in its entirety and replaced with the
following:

                  2.14 The Election of One Bank to Continue Funding. If one or
         more Banks (the "Declining Banks") do not approve a requested Revolving
         Loan or the issuance or amendment of a requested Letter of Credit for
         reasons other than a Default and the other Bank or Banks do approve
         such Revolving Loan or the issuance or amendment of such Letter of
         Credit, the Agent shall notify the Banks. If the Bank or Banks which
         are not the Declining Banks desire, they may (on a pro rata basis among
         the Banks that have elected to continue funding) make the full amount
         of such requested Revolving Loan or issue or amend the requested Letter
         of Credit irrespective of the Declining Banks' disapproval (in such
         case, the Banks that elect to continue funding shall be referred to as
         the "Approving Banks"). In such event, from such date (the "Conversion
         to Single Funding Bank Date") forward (a) all subsequent Revolving
         Loans and Issuances of Letters of Credit or Amendments to Letters of
         Credit that increase the face amount of a Letter of Credit or extend
         the term of a Letter of Credit shall be made unilaterally by the
         Approving Banks and no Letter of Credit thereafter Issued shall be

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 10
<PAGE>


         participated in by the Declining Banks, (b) all Banks' interests in the
         Collateral and loan management decisions shall be pro-rata based on
         each Bank's total Effective Amount of Revolving Loans, plus the
         Effective Amounts of such Bank's L/C Obligations from time to time, and
         (c) the Approving Banks' Uncommitted Line Portion shall be increased on
         the basis of each such advance and Issuance of a Letter of Credit.

                           NOTWITHSTANDING THE FOREGOING, HOWEVER, FOR PURPOSES
         OF ALLOCATING REPAYMENTS PRIOR TO THE OCCURRENCE OF A DEFAULT
         HEREUNDER, THE ADJUSTED PRO RATA SHARE OF THE UNCOMMITTED LINE OF EACH
         BANK SHALL REMAIN FIXED AT THE PERCENTAGE HELD BY SUCH BANK THE DAY
         BEFORE THE CONVERSION TO SINGLE FUNDING BANK DATE, WITHOUT RESPECT TO
         ANY CHANGES WHICH MAY SUBSEQUENTLY OCCUR IN SUCH BANK'S PRO RATA SHARE
         OF THE UNCOMMITTED LINE EXCEPT THAT IN THE EVENT THAT OBLIGATIONS
         BECOME OWING TO BANK OF AMERICA OR BNP PARIBAS AND THEIR AFFILIATES
         AFTER SUCH DATE PURSUANT TO THE OVERDRAFT LINE OR THE BANKCARD LINE OR
         PURSUANT TO SWAP CONTRACTS AS A RESULT OF CONTRACTS OR TRANSACTIONS
         EXISTING ON THE CONVERSION TO SINGLE FUNDING BANK DATE, THE ADJUSTED
         PRO RATA SHARE OF EACH BANK SHALL BE RECALCULATED TO ACCOUNT FOR THE
         INCREASE IN OBLIGATIONS THAT HAVE BECOME OWING TO BANK OF AMERICA OR
         BNP PARIBAS OR THEIR AFFILIATES UNTIL SUCH TIME, IF ANY, THAT ONE BANK
         IS FULLY REPAID. UPON THE OCCURRENCE OF A DEFAULT AND THEREAFTER,
         REPAYMENTS SHALL BE ALLOCATED ACCORDING TO THE ADJUSTED PRO RATA SHARE
         OF THE OUTSTANDING BALANCES HELD BY THE BANKS ON THE DATE OF DEFAULT
         EXCEPT THAT IN THE EVENT THAT OBLIGATIONS BECOME OWING TO BANK OF
         AMERICA OR BNP PARIBAS OR THEIR AFFILIATES AFTER SUCH DATE PURSUANT TO
         THE OVERDRAFT LINE OR THE BANKCARD LINE OR PURSUANT TO SWAP CONTRACTS
         AS A RESULT OF CONTRACTS OR TRANSACTIONS EXISTING ON THE DATE OF SUCH
         DEFAULT, THE ADJUSTED PRO RATA SHARE OF EACH BANK SHALL BE RECALCULATED
         TO ACCOUNT FOR THE INCREASE IN OBLIGATIONS OWING TO BANK OF AMERICA OR
         BNP PARIBAS OR THEIR AFFILIATES.

         18. Schedule 2.01 of the Credit Agreement is deleted in its entirety
and replaced with the Schedule 2.01 attached hereto.

         19. Schedule 11.02 of the Credit Agreement is deleted in its entirety
and replaced with the Schedule 11.02 attached hereto.

         20. Exhibit E to the Credit Agreement is deleted in its entirety and
replaced with the Exhibit E attached hereto.

         21. Renewal; Continued Effect. Except as set forth above, the Credit
Agreement shall continue in full force and effect.

         22. Representations. To induce the Banks to enter into this Amendment,
Borrower ratifies and confirms each representation and warranty set forth in the
Credit Agreement as if such representations and warranties were made on even
date herewith, and further represents and warrants (a) that no material adverse
change has occurred in the financial condition or business prospects of Borrower
since the date of the last financial statements delivered to the Banks, (b) that
no Event of Default exists and no event or condition exists or has occurred
which with

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 11

<PAGE>


passage of time, or notice, or both, would become an Event of Default (a
"Default"), and (c) that Borrower is fully authorized to enter into this
Amendment. BORROWER ACKNOWLEDGES THAT THE CREDIT AGREEMENT PROVIDES FOR A CREDIT
FACILITY THAT IS COMPLETELY OPTIONAL ON THE PART OF THE BANK AND THAT THE BANK
HAS ABSOLUTELY NO DUTY OR OBLIGATION TO ADVANCE ANY REVOLVING LOAN OR TO ISSUE
ANY LETTER OF CREDIT. BORROWER REPRESENTS AND WARRANTS TO BANK THAT BORROWER IS
AWARE OF THE RISKS ASSOCIATED WITH CONDUCTING BUSINESS UTILIZING AN UNCOMMITTED
FACILITY.

         23. Conditions Precedent. As a condition to Bank of America entering
into this Amendment, no Default or Event of Default shall exist on the date
hereof, and Bank of America must have received executed originals of each of the
following documents and instruments, in form and substance satisfactory to Bank
of America:

                  (a)    this Amendment, duly executed by Borrower;

                  (b)    a Promissory Note in the amount of $84,000,000.00, duly
                         executed by Borrower and payable to the order of Bank
                         of America;

                  (c)    a Promissory Note in the amount of $56,000,000.00, duly
                         executed by Borrower and payable to the order of BNP
                         Paribas;

                  (d)    a Second Amended and Restated Guaranty of each of the
                         Guarantors, duly executed by each Guarantor;

                  (e)    an Amended and Restated Security Agreement, duly
                         executed by Borrower;

                  (f)    an Amended and Restated Security Agreement (BNP Paribas
                         Commodity Futures, Inc.), duly executed by Borrower;

                  (g)    an Acknowledgement and Ratification of Subordination
                         and Support Agreements, duly executed by Atmos Energy
                         Corporation Atmos Energy Marketing, LLC; and

                  (g)    such other documents or certificates as Bank of America
                         may reasonably request.

         24. Ratification of Security Agreements. Borrower ratifies and confirms
the Security Agreements, and acknowledges and agrees that references to the
Credit Agreement in such Security Agreements are hereby amended to refer to the
Credit Agreement as amended by this Amendment and that in all other respects
such Security Agreements shall continue in full force and effect, and that
pursuant to such Security Agreements Borrower has granted and hereby confirms
and grants to Bank a continuing first and prior security interest in the
Collateral to secure payment and performance of all Obligations.

FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 12

<PAGE>


         25. Acknowledgment of and Consent to Assignment. The Borrower and the
Guarantors acknowledge and consent to the assignment by Bank of America of a
portion of its interest under the Credit Agreement to BNP Paribas.

         26. Miscellaneous.

                  (a) Severability. In case any of the provisions of this
Amendment shall for any reason be held to be invalid, illegal, or unenforceable,
such invalidity, illegality, or unenforceability shall not affect any other
provision hereof, and this Amendment shall be construed as if such invalid,
illegal, or unenforceable provision had never been contained herein.

                  (b) Capitalized Terms. Except as otherwise defined herein,
capitalized terms shall have the meanings specified in the Credit Agreement.

                  (c) Execution in Counterparts. This Amendment may be executed
in any number of counterparts, all of which taken together shall constitute one
and the same instrument, and any party hereto may execute this Amendment by
signing one or more counterparts.

                  (d) Governing Law. This Amendment shall be construed in
accordance with and governed by the laws of the State of California (without
reference to principles of conflicts of laws), provided, however, that Bank
shall retain all rights under federal law.

                  (e) Rights of Third Parties. All provisions herein are imposed
solely and exclusively for the benefit of Borrower and Bank, and their permitted
successors and assigns, and no other Person shall be a direct or indirect legal
beneficiary of, or have any direct or indirect cause of action or claim in
connection with this Amendment or any of the other Loan Documents.

                  (f) COMPLETE AGREEMENT. THIS WRITTEN AMENDMENT AND THE OTHER
WRITTEN AGREEMENTS ENTERED INTO AMONG THE PARTIES REPRESENT THE FINAL AGREEMENT
AMONG 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 AMONG THE PARTIES.


FOURTH AMENDMENT TO CREDIT AGREEMENT - PAGE 13

<PAGE>


                  Executed as of the day and year first above written



                                        BORROWER:


                                        WOODWARD MARKETING, L.L.C.,
                                        a Delaware limited liability company



                                        By:    /s/ HENRY O. DRILLING
                                           ------------------------------
                                        Name:  Henry O. Drilling
                                             ----------------------------
                                        Title: Sr. Vice President
                                              ---------------------------


                                        BANKS:


                                        BANK OF AMERICA, N. A.,
                                        as Agent


                                        By:    /s/ IRENE C. RUMMEL
                                           ------------------------------
                                        Name:  Irene C. Rummel
                                             ----------------------------
                                        Title: Vice President
                                              ---------------------------

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


                                        By:    /s/ IRENE C. RUMMEL
                                           ------------------------------
                                        Name:  Irene C. Rummel
                                             ----------------------------
                                        Title: Vice President
                                              ---------------------------

                                        BNP PARIBAS,
                                        as a Bank


                                        By:    /s/ EDWARD K. CHIN
                                           ------------------------------
                                        Name:  Edward K. Chin
                                             ----------------------------
                                        Title: Director
                                              ---------------------------


                                        By:    /s/ OLIVIER LE BIHAN
                                           ------------------------------
                                        Name:  Olivier Le Bihan
                                             ----------------------------
                                        Title: Vice President
                                              ---------------------------

SIGNATURE PAGE - FOURTH AMENDMENT TO CREDIT AGREEMENT


<PAGE>


                                        GUARANTORS:


                                        WOODWARD MARKETING, INC.


                                        By:     /s/ HENRY O. DRILLING
                                           ----------------------------------
                                        Name:   Henry O. Drilling
                                             --------------------------------
                                        Title:  Sr. Vice President
                                              -------------------------------


                                        ATMOS ENERGY MARKETING, LLC


                                        By:     /s/ LAURIE M. SHERWOOD
                                           -------------------------------
                                        Name:   Laurie M. Sherwood
                                             --------------------------------
                                        Title:  Vice President and Treasurer
                                              -------------------------------



                                             /s/ J. D. WOODWARD
                                        ----------------------------------------
                                                J. D. WOODWARD



                                             /s/ JAMES KIFER
                                        ----------------------------------------
                                                JAMES KIFER


SIGNATURE PAGE - FOURTH AMENDMENT TO CREDIT AGREEMENT




<PAGE>




                                  SCHEDULE 2.01

                              UNCOMMITTED LINE AND
                            UNCOMMITTED LINE PORTION
                         (EXCLUDING OVERDRAFT LINES AND
                                 SWAP CONTRACTS)


I. Until such time as the Borrower first elects a Borrowing Base Sub-Cap of
$110,000,000 or more:

<Table>
<Caption>

                                                                    Pro Rata
Line:                 Bank                  Dollar Amount           Share
-----                 ----                  -------------           -----
<S>                 <C>                     <C>                     <C>
Borrowing Base      Bank of America         $75,000,000.00           75%
Line
                    BNP Paribas             $25,000,000.00           25%

Collateralized      Bank of America         $11,250,000.00           75%
L/C Line
                    BNP Paribas              $3,750,000.00           25%
</Table>



II. Commencing with and at all times after the date the Borrower first elects a
Borrowing Base Sub-Cap of $110,000,000 or more:

<Table>
<Caption>

Line:                    Bank                     Dollar Amount            Share
-----                    ----                     -------------            -----
<S>                      <C>                      <C>                      <C>
Borrowing Base           Bank of America          $75,000,000.00            60%
Line
                         BNP Paribas              $50,000,000.00            40%

Collateralized           Bank of America          $ 9,000,000.00            60%
L/C Line
                         BNP Paribas              $ 6,000,000.00            40%
</Table>

<PAGE>




                                 SCHEDULE 11.02


                    LENDING OFFICES AND ADDRESSES FOR NOTICES



BANK OF AMERICA, N. A.,
as Agent


Bank of America, N. A.
333 Clay Street, Suite 4550
Houston, Texas  77002
Attention:  Irene C. Rummel
Telephone:  (713) 651-4921
Facsimile:  (713) 651-4801



AGENT'S PAYMENT OFFICE:


Bank of America, N. A.
Bank of America Plaza, 8th Floor
901 Main Street
Dallas, Texas  75202-3714



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

Bank of America, N. A.
International Trade Operations Center
333 South Beaudry Avenue, 19th Floor
Los Angeles, California 90017
Attention:  Sandra Leon
Telephone:  (213) 345-5231
Facsimile:  (213) 345-6694


<PAGE>


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


Bank of America, N. A.
333 Clay Street, Suite 4550
Houston, Texas  77002
Attention:  Irene C. Rummel
Telephone:  (713) 651-4921
Facsimile:  (713) 651-4801



BNP PARIBAS,
as a Bank


BNP Paribas
787 Seventh Avenue
New York, New York  10019
Attention:  Ed Chin
Telephone:  (212) 841 2020
Facsimile:  (212) 841 2537



<PAGE>


                                    EXHIBIT E

                                     FORM OF
                    BORROWING BASE COLLATERAL POSITION REPORT

                                     [Date]

Bank of America, N. A., as Agent
333 Clay Street, Suite 4550
Houston, Texas  77002
Attention:  Irene C. Rummel
Telephone:  (713) 651-4921
Facsimile:  (713) 651-4801

         Re:  Credit Agreement, dated to be effective as of August 9, 2000 (as
              amended or supplemented from time to time, the "Agreement"), by
              and among Woodward Marketing, L.L.C. (the "Borrower"), the banks
              that from time to time are parties thereto, and Bank of America,
              N. A., as Agent

Ladies and Gentlemen:

         The Borrower, acting through its duly authorized Responsible Officer
(as that term is defined in the Agreement), deliver the attached report to the
Banks and certify to each of the Banks that it is in compliance with the
Agreement. Further, the undersigned hereby certifies that the Net Position has
at no time exceeded the limitations set forth in Section 8.11 of the Agreement
and that the undersigned has no knowledge of any Defaults or Events of Default
under the Agreement which exist as of the date of this letter.

         The undersigned also certifies that the amounts set forth on the
attached report constitute all Collateral which has been or is being used in
determining availability for an advance or letter of credit issued under the
Borrowing Base Line as of the preceding date. This certificate and attached
reports are submitted pursuant to Section 7.02(b) of the Agreement. Capitalized
terms used herein and in the attached reports have the meanings specified in the
Agreement.

                                       Very truly yours,

                                       WOODWARD MARKETING, L.L.C.



                                       By:
                                          -------------------------------------
                                       Name:
                                            -----------------------------------
                                       Title:  Responsible Officer


<PAGE>


                           WOODWARD MARKETING, L.L.C.,
                    BORROWING BASE COLLATERAL POSITION REPORT
                                  AS OF [DATE]

         In my capacity as Responsible Officer for Woodward Marketing, L.L.C., I
hereby certify that as of the date written above, the amounts indicated below
were accurate and true as of the date of preparation. I also certify that the
net long or short position has not exceeded the limitations set forth in Section
8.11 of the Credit Agreement.

<Table>

I.   COLLATERAL
<S>                                                                   <C>                 <C>            <C>
     A.   Cash Collateral                                             $_______            100%           $________

     B.   BA Futures equity                                           $_______             90%           $________

     C.   BNP Paribas Futures equity                                  $_______             90%           $________

     D.   Tier I Accounts                                             $_______             90%           $________

     E.   Tier II Accounts                                            $_______             85%           $________

     F.   Tier I Unbilled Accounts                                    $_______             85%           $________

     G.   Tier II Unbilled Accounts                                   $_______             80%           $________

     H.   Eligible Inventory                                          $_______             80%           $________

     I.   Eligible Exchange Receivables                               $_______             80%           $________

     J.   Undelivered Product Value                                   $_______             80%           $________

     K.   First purchaser liability                                   $(______)           100%           $(_______)

     L.   125% of Net amounts due Bank of America
          under commodity Swap Contracts                              $(______)           125%           $(_______)

     M.   125% of Net Amounts due BNP Paribas
          under commodity Swap Contracts                              $(______)           125%           $(_______)

     N.   100% of Borrower's Unrealized Mark-to-Market Losses         $(______)           100%           $(_______)

                                                                      ---------           ----            ---------

                                                                      ==========          ====           ==========

     TOTAL COLLATERAL                                                 $_______            ____           $_________

     BORROWING BASE SUB-CAP                                                                              $_________

     BORROWING BASE ADVANCE CAP (Least of
     $125,000,000.00, Borrowing Base Sub-Cap or Total Collateral)                                        $_________

II.  BANK OUTSTANDINGS

     A.   Loans from the Banks                                                                           $_________

     B.   L/Cs from the Banks                                                                            $_________


TOTAL OUTSTANDINGS UNDER BORROWING BASE LINE                                                             $_________

III. EXCESS/(DEFICIT) (I-II)                                                                             $_________

IV.  NET SHORT OR LONG POSITION __________ MMBTUS
</Table>

<PAGE>


Attached hereto are (i) an aging report, (ii) a schedule of netted qualified
exchange balances, (iii) a schedule of qualified inventory and (iv) a schedule
of all contras applied against (i), (ii), and (iii).



                                    By:
                                       ----------------------------------------
                                    Responsible Officer