<PAGE>
 
                                                                    EXHIBIT 10.6



                                Credit Agreement

                                     Among

                        Mississippi Chemical Corporation

                                      And

                            The Lenders Party Hereto

                                      And

                         Harris Trust and Savings Bank,
                            as Administrative Agent

                                      And

                       Bank of Montreal, Chicago Branch,
                              as Syndication Agent

                                      And

                            Credit Agricole Indosuez
                                  as Co-Agent



                         Dated as of November 25, 1997
<PAGE>
 
                               TABLE OF CONTENTS

                        MISSISSIPPI CHEMICAL CORPORATION

                                CREDIT AGREEMENT
<TABLE>
<S>                    <C>                                                                                 <C>
Section 1.             The Revolving Credit and Swing Line..............................................    1
   Section 1.1.        The Revolving Credit.............................................................    1
   Section 1.2.        Swingline Loans under the Revolving Credit.......................................    4
          (a)          Swingline Commitment.............................................................    4
          (b)          Refunding Loans..................................................................    4
          (c)          Participations...................................................................    5
   Section 1.3.        Interest Rates...................................................................    5
          (a)          Base Rate Loans..................................................................    5
          (b)          Eurodollar Loans.................................................................    5
          (c)          Fed Funds Rate Loans.............................................................    5
          (d)          Default Rate.....................................................................    5
   Section 1.4.        Conversion and Continuation of Loans.............................................    6
   Section 1.5.        Letters of Credit................................................................    6
   Section 1.6.        Reimbursement Obligation.........................................................    8
   Section 1.7.        Manner of Borrowing Revolving Credit Loans and Swingline Loans...................    8
   Section 1.8.        Participation in L/Cs............................................................   10
   Section 1.9.        Capital Adequacy.................................................................   10
Section 2.             The Bid Facility.................................................................   11
   Section 2.1.        The Bid Loans....................................................................   11
   Section 2.2.        Requests for Bid Loans...........................................................   11
          (a)          Requests and Confirmations.......................................................   11
          (b)          Invitation to Bid................................................................   12
          (c)          Bids.............................................................................   12
   Section 2.3.        Notice of Bids...................................................................   12
   Section 2.4.        Acceptance or Rejection of Bids..................................................   13
   Section 2.5.        Notice of Acceptance or Rejection of Bids........................................   13
          (a)          Notice to Banks Making Successful Bids...........................................   13
          (b)          Notice to all Banks..............................................................   14
          (c)          Disbursement of Bid Loans........................................................   14
          (d)          Interest on Bid Loans............................................................   14
   Section 2.6.        Telephonic Notice................................................................   14
Section 3.             The Notes, Fees, Prepayments, Terminations and Application of Payments...........   15
   Section 3.1.        The Notes........................................................................   15
   Section 3.2.        Facility Fee.....................................................................   15
</TABLE> 
<PAGE>
 
<TABLE> 
<C>                    <S>                                                                                <C>
   Section 3.3.        Agent's Fees.....................................................................   16
   Section 3.4         .................................................................................   16
          (a)          Optional Prepayments of Base Rate Loans..........................................   16
          (b)          Optional Prepayments of Swingline Loans..........................................   16
          (c)          Optional Prepayments of Eurodollar Loans.........................................   16
          (d)          Mandatory Prepayments of Excess Borrowings.......................................   16
   Section 3.5.        Revolving Credit Termination.....................................................   17
   Section 3.6.        Place and Application of Payments................................................   17
Section 4.             Definitions......................................................................   17
   Section 4.1.        Certain Definitions..............................................................   17
   Section 4.2.        Accounting Terms.................................................................   28
Section 5.             Representations and Warranties...................................................   28
   Section 5.1.        Organization and Qualification; Non-Contravention................................   28
   Section 5.2.        Financial Reports................................................................   29
   Section 5.3.        Litigation; Tax Returns; Approvals...............................................   29
   Section 5.4.        Regulation U.....................................................................   29
   Section 5.5.        No Default.......................................................................   30
   Section 5.6.        ERISA............................................................................   30
   Section 5.7.        Debt and Security Interests......................................................   30
   Section 5.8.        Subsidiaries.....................................................................   30
   Section 5.9.        Accurate Information.............................................................   30
   Section 5.10.       Enforceability...................................................................   30
   Section 5.11.       Restrictive Agreements...........................................................   30
   Section 5.12.       No Violation of Law..............................................................   31
   Section 5.13.       No Default Under Other Agreements................................................   31
   Section 5.14.       Status Under Certain Laws........................................................   31
   Section 5.15.       Pari Passu.......................................................................   31
Section 6.             Conditions Precedent.............................................................   31
   Section 6.1.        Initial Extension of Credit......................................................   31
   Section 6.2.        Each Extension of Credit.........................................................   32
   Section 6.3.        Legal Matters....................................................................   33
   Section 6.4.        Documents........................................................................   33
Section 7.             Covenants........................................................................   33
   Section 7.1.        Maintenance of Property..........................................................   33
   Section 7.2.        Taxes............................................................................   34
   Section 7.3.        Maintenance of Insurance.........................................................   34
   Section 7.4.        Financial Reports................................................................   34
   Section 7.5.        Inspection.......................................................................   35
   Section 7.6.        Consolidation and Merger.........................................................   35
   Section 7.7.        Transactions with Affiliates.....................................................   36
</TABLE> 
<PAGE>
 
<TABLE> 
<C>                    <S>                                                                                <C>

   Section 7.8.        Dividends and Certain Other Restricted Payments..................................   36
   Section 7.9.        Liens............................................................................   36
   Section 7.10.       Borrowings and Guaranties........................................................   38
   Section 7.11.       Investments, Loans, Advances and Acquisitions....................................   39
   Section 7.12.       Sale of Property.................................................................   40
   Section 7.13.       Notice of Suit or Adverse Change in Business or Default..........................   41
   Section 7.14.       ERISA............................................................................   41
   Section 7.15.       Use of Proceeds..................................................................   41
   Section 7.16.       Compliance with Laws, etc........................................................   42
   Section 7.17.       Sale and Leaseback Transactions..................................................   42
   Section 7.18.       Fiscal Quarters..................................................................   42
   Section 7.19.       New Subsidiaries.................................................................   42
   Section 7.20.       Maximum Leverage Ratio...........................................................   42
   Section 7.21.       Minimum Interest Coverage Ratio..................................................   42
   Section 7.22.       Minimum Tangible Net Worth.......................................................   42
   Section 7.23.       Operating Leases.................................................................   43
   Section 7.24.       No Restrictions on Subsidiaries..................................................   43
Section 8.             Events of Default and Remedies...................................................   43
   Section 8.1.        Definitions......................................................................   43
   Section 8.2.        Remedies for Non-Bankruptcy Defaults.............................................   45
   Section 8.3.        Remedies for Bankruptcy Defaults.................................................   45
   Section 8.4.        L/Cs.............................................................................   45
Section 9.             Change in Circumstances Regarding Fixed Rate Loans...............................   45
   Section 9.1.        Change of Law....................................................................   45
   Section 9.2.        Unavailability of Deposits or Inability to Ascertain the Adjusted Eurodollar Rate   46
   Section 9.3.        Taxes and Increased Costs........................................................   46
   Section 9.4.        Funding Indemnity................................................................   47
   Section 9.5.        Lending Branch...................................................................   48
   Section 9.6.        Discretion of Bank as to Manner of Funding.......................................   48
   Section 9.7.        Mitigation of Circumstances......................................................   48
Section 10.            The Agents.......................................................................   49
   Section 10.1.       Appointment and Powers...........................................................   49
   Section 10.2.       Powers...........................................................................   49
   Section 10.3.       General Immunity.................................................................   49
   Section 10.4.       No Responsibility for Loans, Recitals, etc.......................................   50
   Section 10.5.       Right to Indemnity...............................................................   50
   Section 10.6.       Action Upon Instructions of Banks................................................   50
   Section 10.7.       Employment of Agents and Counsel.................................................   50
   Section 10.8.       Reliance on Documents; Counsel...................................................   50
</TABLE> 
<PAGE>
 
<TABLE> 
<C>                    <S>                                                                                <C>
   Section 10.9.       May Treat Payee as Owner.........................................................   50
   Section 10.10.      Agents' Reimbursement............................................................   51
   Section 10.11.      Rights as a Bank.................................................................   51
   Section 10.12.      Bank Credit Decision.............................................................   51
   Section 10.13.      Resignation of Agent.............................................................   51
   Section 10.14.      Duration of Agency...............................................................   51
   Section 10.15.      Syndication  Agent and Co-Agent..................................................   52
Section 11.            Miscellaneous....................................................................   52
   Section 11.1.       Amendments and Waivers...........................................................   52
   Section 11.2.       Waiver of Rights.................................................................   52
   Section 11.3.       Several Obligations..............................................................   53
   Section 11.4.       Non-Business Day.................................................................   53
   Section 11.5.       Documentary Taxes................................................................   53
   Section 11.6.       Representations..................................................................   53
   Section 11.7.       Notices..........................................................................   53
   Section 11.8.       Costs and Expenses; Indemnity....................................................   53
   Section 11.9.       Counterparts.....................................................................   55
   Section 11.10.      Successors and Assigns...........................................................   55
   Section 11.11.      No Joint Venture.................................................................   55
   Section 11.12.      Severability.....................................................................   55
   Section 11.13.      Table of Contents and Headings...................................................   55
   Section 11.14.      Sharing of Payments..............................................................   55
   Section 11.15.      Jurisdiction.....................................................................   56
   Section 11.16.      Participants and Note Assignees..................................................   56
   Section 11.17.      Assignment of Commitments by Banks...............................................   56
Signature Page..........................................................................................   58
     Exhibit A         Revolving Credit Note
     Exhibit B         Application and Agreement for Letter of Credit
     Exhibit C         Bid Loan Request Confirmation
     Exhibit D         Invitation to Bid
     Exhibit E         Confirmation of Bid
     Exhibit F         Notice of Acceptance of Bid
     Exhibit G         Schedule of Subsidiaries
     Exhibit H         Compliance Certificate
     Exhibit I         Form of Legal Opinion of Borrowers' Counsel
     Exhibit J         Farmland MissChem Project Contingent Obligations
     Exhibit K         Pricing Ratio Certificate
     Exhibit L         Existing Letters of Credit
     Schedule 5.3.     Litigation
     Schedule 7.24.    Existing Restrictions
</TABLE> 
<PAGE>
 
                        MISSISSIPPI CHEMICAL CORPORATION

                                CREDIT AGREEMENT

Harris Trust and Savings Bank
Chicago, Illinois

The from time to time lenders parties hereto

Ladies and Gentlemen:

     The undersigned Mississippi Chemical Corporation, a Mississippi corporation
(the "Borrower"), applies to you for your several commitments, subject to all
the terms and conditions hereof and on the basis of the representations and
warranties hereinafter set forth, to make a revolving credit (the "Revolving
Credit"), a swing line credit (the "Swing Line") and a competitive bid facility
(the "Bid Facility") available to the Borrower, all as more fully hereinafter
set forth.  Each of you is hereinafter referred to individually as "Bank" and
collectively as "Banks."  Harris Trust and Savings Bank in its individual
capacity is sometimes referred to herein as "Harris", and in its capacity as
Administrative Agent for the Banks is hereinafter in such capacity called the
"Administrative Agent."  Bank of Montreal in its capacity as Syndication Agent
for the Banks is hereinafter in such capacity called the "Syndication Agent."
Credit Agricole Indosuez, in its capacity as Co-Agent for the Banks is
hereinafter in such capacity collectively called the "Co-Agent."  All
capitalized terms not defined in the text of this Agreement are defined in
Section 4 hereof.

Section 1.    The Revolving Credit and Swing Line.

          Section 1.1.  The Revolving Credit.  (a) Subject to all of the terms
and conditions hereof, the Banks agree, severally and not jointly, to extend a
Revolving Credit to the Borrower which may be utilized by the Borrower in the
form of loans (individually a "Revolving Credit Loan" and collectively the
"Revolving Credit Loans") and L/Cs (as hereinafter defined).  The aggregate
principal amount of all Loans (as hereinafter defined) plus the maximum amount
available for drawing under all L/Cs and the aggregate principal amount of all
unpaid Reimbursement Obligations (as hereinafter defined) at any time
outstanding (collectively the "Revolving Credit Obligations") may not exceed the
sum of the Revolving Credit Commitments (as hereinafter defined) at any time.
The Revolving Credit shall be available to the Borrower, and may be availed of
by the Borrower from time to time, be repaid (subject to the restrictions on
prepayment set forth herein) and used again, during the period from the date
hereof to and including November 25, 2002 (as the same may be extended from time
to time in accordance with the provisions of Section 1.1(d) hereof, the
"Termination Date"), at which time the entire outstanding principal amount of
all Revolving Credit Obligations, together with all accrued and unpaid interest
thereon, shall be due and payable.
<PAGE>
 
       (b) The respective maximum aggregate principal amounts of the Revolving
Credit at any one time outstanding and the percentage (the "Commitment
Percentage") of the Revolving Credit available at any time which each Bank by
its acceptance hereof severally agrees to make available to the Borrower are as
follows (collectively, the "Revolving Credit Commitments" and individually, a
"Revolving Credit Commitment"):
<TABLE>
<S>                                                            <C>                           <C>
Harris Trust and Savings Bank                                     $ 35,000,000.00                    17.5%
---------------------------------------------------------------------------------------------------------
Credit Agricole Indosuez                                            32,500,000.00                   16.25%
---------------------------------------------------------------------------------------------------------
Banque Nationale de Paris, Houston Agency                           20,000,000.00                      10%
---------------------------------------------------------------------------------------------------------
The Fuji Bank, Limited                                              20,000,000.00                      10%
---------------------------------------------------------------------------------------------------------
Bank of America National Trust and Savings                          17,500,000.00                    8.75%
 Association
---------------------------------------------------------------------------------------------------------
The Bank of Nova Scotia, Atlanta Agency                             15,000,000.00                     7.5%
---------------------------------------------------------------------------------------------------------
SunTrust Bank, Atlanta                                              15,000,000.00                     7.5%
---------------------------------------------------------------------------------------------------------
First Union National Bank                                           15,000,000.00                     7.5%
---------------------------------------------------------------------------------------------------------
ABN AMRO Bank N.V.                                                  10,000,000.00                       5%
---------------------------------------------------------------------------------------------------------
The Dai-Ichi Kangyo Bank, Ltd.                                      10,000,000.00                       5%
---------------------------------------------------------------------------------------------------------
Deposit Guaranty National Bank                                      10,000,000.00                       5%
                                                                  ---------------
---------------------------------------------------------------------------------------------------------
Total                                                             $200,000,000.00                     100%
---------------------------------------------------------------------------------------------------------
</TABLE>

       (c) Loans under the Revolving Credit may be Eurodollar Loans or Base Rate
Loans.  Each Borrowing under the Revolving Credit shall be made by each Bank in
an amount equal to its Commitment Percentage of the amount of such Borrowing.
Each Borrowing of Base Rate Loans under the Revolving Credit shall be in an
amount not less than $5,000,000 or such greater amount which is an integral
multiple of $1,000,000 and each Borrowing of Eurodollar Loans shall be in an
amount not less than $10,000,000 or such greater amount which is an integral
multiple of $1,000,000.

       (d) At any time not earlier than 120 days prior to, nor later than 90
days prior to, each annual anniversary of the date hereof (each an "Anniversary
Date"), the Borrower may request that the Banks extend the then scheduled
Termination Date to the date one year from such Termination Date.  Each such
request by the Borrower shall be deemed to be a representation and warranty by
the Borrower to the Banks that no material adverse change in the financial
condition of the Borrower and its Subsidiaries, taken as a whole, has occurred
since the date of the most recent financial reports delivered to the Banks in
accordance with Section 7.4(b) hereof.  If such request is made by the Borrower
each Bank shall inform the Administrative Agent of its willingness to extend the
Termination Date no later than 30 days after the Banks receive such request.
Any Bank's failure to respond by such date shall indicate its unwillingness 
<PAGE>
 
to agree to such requested extension. At any time more than 30 days before such
Anniversary Date Banks having aggregate Commitment Percentages of at least 80%
of the Revolving Credit Commitments then in effect (the "Extending Banks") may
propose, by written notice to the Borrower, an extension of this Agreement to
the date one year from the applicable Termination Date on such terms and
conditions as the Extending Banks may then require.  If the extension of this
Agreement to the date one year from the Applicable Termination Date is
acceptable to the Borrower on the terms and conditions proposed by the Extending
Banks, the Borrower shall notify the Extending Banks of its acceptance of such
terms and conditions no later than the Anniversary Date, and such later date
will become the Termination Date hereunder and this Agreement shall otherwise be
amended in the manner described in the Extending Banks' notice proposing the
extension of this Agreement upon the Agent's receipt of (i) an amendment to this
Agreement signed by the Borrower and all of the Extending Banks, (ii)
resolutions of the Borrower's Board of Directors authorizing such extension and
(iii) an opinion of counsel to the Borrower equivalent in form and substance to
the form of opinion attached hereto as Exhibit I and otherwise acceptable to the
Extending Banks.  If the Borrower and the Extending Banks agree upon the terms
of an extension of the Termination Date, the Borrower may elect either (i) to
terminate the Revolving Credit Commitments of each Bank that is not an Extending
Bank (each a "Nonextending Bank") in whole on such Anniversary Date, at which
time all Loans and other amounts payable under the Loan Documents to the
Nonextending Banks shall become immediately due and payable, or (ii) to replace
such Nonextending Banks with one or more financial institutions acceptable to
the Borrower and the Administrative Agent (each a "Replacement Bank").  If the
Borrower elects to replace a Nonextending Bank, such replacement shall become
effective as of the date the Nonextending Banks' Revolving Credit Commitments
terminate (which shall be no later than the Anniversary Date) and all of the
following conditions are satisfied:

            (A) the unpaid principal amount of all Loans and Reimbursement
     Obligations made by each Nonextending Bank whose Revolving Credit
     Commitment is to terminate, together with accrued interest thereon and all
     other amounts payable under the Loan Documents to such Nonextending Bank,
     including any facility fee accrued through the date of such termination,
     shall have been paid in full and all of such Nonextending Banks'
     participations in L/Cs shall have been reallocated among the Extending
     Banks;

            (B) such Replacement Bank shall agree in writing to be bound by all
     of the terms and provisions of this Agreement, such agreement to specify
     the amount of the Revolving Credit Commitment of such Replacement Bank and
     to be otherwise in form and substance satisfactory to the Administrative
     Agent, and shall make Loans to the Borrower in principal amounts which bear
     the same ratio to the amounts of the Loans made by the other Extending
     Banks then outstanding as the Revolving Credit Commitment of such
     Replacement Bank bears to the then Revolving Credit Commitments of all
     other Extending Banks; and
<PAGE>
 
            (C) a copy of such agreement and of evidence satisfactory to the
     Administrative Agent of the making of such Loans shall be furnished to the
     Administrative Agent and the Extending Banks.

     Section 1.2. Swingline Loans under the Revolving Credit. (a) Swingline
Commitment. Subject to the terms and conditions hereof and in reliance on the
obligations of the Banks to Harris under this Section 1.2, Harris agrees to
advance one or more swingline loans (each a "Swingline Loan") to the Borrower
from time to time before the Termination Date on a revolving basis up to
$25,000,000 in aggregate principal amount at any time outstanding; provided that
Harris shall have no obligation to advance any Swingline Loan if the Total
Outstandings would thereby exceed the sum of the Revolving Credit Commitments
then in effect. All Swingline Loans will be Fed Funds Rate Loans or Offered Rate
Loans and will be in an amount not less than $250,000 or an integral multiple of
$100,000 in excess thereof. Swingline Loans may be repaid and their principal
amount reborrowed before the Termination Date, subject to the terms and
conditions hereof. Each Swingline Loan shall have a maturity of up to the
seventh day after such Swingline Loan was made. No more than 5 Swingline Loans
may be outstanding at any time.

     The Borrower may elect that each Swingline Loan shall bear interest
(computed on the basis of a year of 365/366 days and actual days elapsed) on the
unpaid principal amount thereof from the date such Swingline Loan is made until
the last day of the Interest Period applicable thereto at the rate per annum
quoted to the Borrower by Harris for the Interest Period applicable thereto,
billable on the last day of each month (each such Swingline Loan is hereinafter
referred to as an "Offered Rate Loan"); provided, however, that the Borrower
understands and agrees that Harris has no obligation to quote rates or to make
any such Offered Rate Loan and may refuse to make any such Offered Rate Loan
after receiving a request therefor from the Borrower.  The Borrower acknowledges
and agrees that the interest rate quoted by Harris for any Offered Rate Loan may
not be the best or lowest rate offered to other customers of Harris and may not
be the same rate offered to other customers of Harris for loans of similar
amounts and maturities, but is the rate at which Harris in its sole and
exclusive discretion is willing to make such Loan to the Borrower for the
specified amount and maturity.

     (b) Refunding Loans.  In its sole and absolute discretion, Harris may at
any time, on behalf of the Borrower (which hereby irrevocably authorizes Harris
to act on its behalf for such purpose), request each Bank to make a Base Rate
Loan under the Revolving Credit in an amount equal to such Bank's Commitment
Percentage of the amount of the Swingline Loans outstanding on the date such
notice is given.  Unless any of the conditions of Section 6.2 are not fulfilled
on such date, each Bank shall make the proceeds of its requested Base Rate Loan
available to Harris, in immediately available funds, at the principal office of
Harris in Chicago, Illinois, before 12:00 Noon (Chicago time) on the Business
Day following the day such notice is given.  The proceeds of such Base Rate
Loans shall be immediately applied to repay the outstanding Swingline Loans.
The Borrower authorizes Harris to charge the Borrower's accounts with Harris (up
to the amount available in such accounts) to pay the amount of any such
outstanding Swingline Loans to the extent amounts received from the Banks are
not sufficient to repay in full such Swingline Loans.
<PAGE>
 
     (c) Participations.  If any Bank refuses or otherwise fails to make a
Revolving Credit Loan when requested by Harris pursuant to Section 1.2(b) above
(because the conditions in Section 6.2 are not satisfied or otherwise), such
Bank will, by the time and in the manner such Revolving Credit Loan was to have
been funded to Harris, purchase from Harris an undivided participating interest
in the outstanding Swingline Loans in an amount equal to its Commitment
Percentage of the aggregate principal amount of Swingline Loans that were to
have been repaid with such Revolving Credit Loans.  Each Bank that so purchases
a participation in a Swingline Loan shall thereafter be entitled to receive its
Commitment Percentage of each payment of principal received on the Swingline
Loan and of interest received thereon accruing from the date such Bank funded to
Harris its participation in such Loan.  The obligation of the Banks to Harris
shall be absolute and unconditional and shall not be affected or impaired by any
Event of Default or Potential Default which may then be continuing hereunder.

     Section 1.3.  Interest Rates. (a) Base Rate Loans. Each Base Rate
Loan shall bear interest (computed on the basis of a year of 365/366 days and
actual days elapsed) on the unpaid principal amount thereof from the date such
Loan is made until maturity (whether by acceleration, upon prepayment or
otherwise) at a rate per annum equal to the sum of the Applicable Margin and the
Base Rate from time to time in effect, payable monthly in arrears on the last
day of each calendar month, commencing on the first of such dates occurring
after the date hereof and at maturity (whether by acceleration, upon prepayment
or otherwise).

     (b) Eurodollar Loans.  Each Eurodollar Loan under the Revolving Credit
shall bear interest (computed on the basis of a year of 360 days and actual days
elapsed) on the unpaid principal amount thereof from the date such Loan is made
until the last day of the Interest Period applicable thereto or, if earlier,
until maturity (whether by acceleration or otherwise) at a rate per annum equal
to the sum of the Applicable Margin and the Adjusted Eurodollar Rate, payable on
the last day of each Interest Period applicable thereto or at maturity (whether
by acceleration or otherwise) and, with respect to Eurodollar Loans with an
Interest Period in excess of three months, on the date occurring every three
months from the first day of the Interest Period applicable thereto.

     (c) Fed Funds Rate Loans.  Each Fed Funds Rate Loan shall bear interest
(computed on the basis of a year of 365/366 days and actual days elapsed) on the
principal amount thereof from the date such Loan is made until maturity (whether
by acceleration, upon prepayment or otherwise) at a rate per annum equal to the
sum of the Applicable Margin and the Fixed Fed Funds Rate from time to time in
effect, billable on the last day of each month.

     (d) Default Rate.  If any Event of Default shall have occurred, all Loans
and Reimbursement Obligations shall bear interest from the date such Event of
Default occurred, payable on demand, at a rate per annum equal to:
<PAGE>
 
            (i) with respect to any Base Rate Loan, the sum of 2% plus the Base
     Rate (computed on the basis of a year of 365/366 days and actual days
     elapsed) from time to time in effect; and

            (ii) with respect to any Fixed Rate Loan, the sum of 2% plus the
     rate of interest in effect thereon at the time of such default (computed on
     the basis of a year of 360 days and actual days elapsed) until the end of
     the Interest Period then applicable thereto, and, thereafter, at a rate per
     annum equal to the sum of 2% plus the Base Rate (computed on the basis of a
     year of 365/366 days and actual days elapsed) from time to time in effect.

       Section 1.4.  Conversion and Continuation of Loans.  (a) Provided that
no Event of Default or Potential Default has occurred and is continuing, the
Borrower shall have the right, subject to the other terms and conditions of this
Agreement, to continue in whole or in part (but, if in part, in the minimum
amount specified for Eurodollar Loans in Section 1.1 hereof) any Eurodollar Loan
from any current Interest Period into a subsequent Interest Period, provided
that the Borrower shall give the Administrative Agent notice of the continuation
of any such Loan as provided in Section 1.7 hereof.

       (b) In the event that the Borrower fails to give notice pursuant to
Section 1.7 hereof of the continuation of any Eurodollar Loan or fails to
specify the Interest Period applicable thereto, or an Event of Default or
Potential Default has occurred and is continuing at the time any such Loan is to
be continued hereunder, then such Loan shall be automatically converted as (and
the Borrower shall be deemed to have given notice requesting) a Base Rate Loan,
subject to Sections 8.2 and 8.3 hereof, unless paid in full on the last day of
the then applicable Interest Period.

       (c) Provided that no Event of Default or Potential Default has occurred
and is continuing, the Borrower shall have the right, subject to the terms and
conditions of this Agreement, to convert Revolving Credit Loans of one type (in
whole or in part) into Revolving Credit Loans of another type from time to time
provided that:  (i) the Borrower shall give the Administrative Agent notice of
each such conversion as provided in Section 1.7 hereof, (ii) the principal
amount of any Revolving Credit Loan converted hereunder shall be in an amount
not less than the minimum amount specified for the type of Loan in Section 1.1
hereof, (iii) after giving effect to any such conversion in part, the principal
amount of any Eurodollar Loan then outstanding shall not be less than the
minimum amount specified for a Eurodollar Loan in Section 1.1 hereof, (iv) any
conversion of a Loan hereunder shall only be made on a Business Day, and (v) any
Eurodollar Loan may be converted only on the last day of the Interest Period
then applicable thereto.

       Section 1.5. Letters of Credit. (a) Subject to all the terms and
conditions hereof, satisfaction of all conditions precedent to borrowing under
this Agreement and so long as no Potential Default or Event of Default is in
existence, at the Borrower's request Harris may in its discretion issue letters
of credit (an "L/C" and collectively the "L/Cs") for the account of the Borrower
subject to availability under the Revolving Credit, and the Banks hereby agree
to participate therein as more fully 
<PAGE>
 
described in Section 1.8 hereof. Each L/C shall be issued pursuant to an
application for letter of credit (the "L/C Agreement") in the form of Exhibit B
hereto. The L/Cs shall consist of standby and commercial letters of credit in an
aggregate face amount not to exceed $30,000,000. Each L/C shall have an expiry
date not more than one year from the date of issuance thereof (but in no event
later than the Termination Date). The amount available to be drawn under each
L/C issued pursuant hereto shall be deducted from the credit otherwise available
under the Revolving Credit. In consideration of the issuance of L/Cs the
Borrower agrees to pay Harris for the benefit of the Banks a fee (the "L/C
Participation Fee") in the amount per annum equal to the Applicable Margin for
Eurodollar Loans (computed on the basis of a 360-day year and actual days
elapsed) of the face amount for each L/C issued for the account of the Borrower
hereunder. In addition, the Borrower shall pay Harris (x) a fee (the "L/C
Issuance Fee") in the amount per annum equal to (i) for standby L/Cs, eight-
hundredths of one percent (0.08%) of the stated amount of each standby L/C
issued hereunder and (ii) for commercial L/Cs, the customary issuance fee for
commercial L/Cs as may be established by Harris from time to time, and (y) such
drawing, negotiation, amendment and other administrative fees in connection with
each L/C as may be established by Harris from time to time (the "L/C
Administrative Fee"). All L/C Issuance Fees and L/C Participation Fees shall be
payable quarterly in arrears on the last day of each March, June, September and
December commencing December 31, 1997 and on the Termination Date, and all L/C
Administrative Fees shall be payable on the date of issuance of each L/C
hereunder and on the date required by Harris.

     Upon satisfaction of all conditions precedent to the initial Loan
hereunder, without any further action on the part of the Borrower, Harris, the
Administration Agent or any Bank, (i) each of the letters of credit listed on
Exhibit L hereto (the "Existing L/Cs") previously issued by Harris for the
account of the Borrower or Triad Nitrogen, Inc. under the Existing Agreements
shall be deemed for all purposes of this Agreement to be an L/C issued
hereunder, (ii) each application and agreement for a letter of credit pursuant
to which each Existing L/C was issued shall be deemed for all purposes of this
Agreement to be an L/C Agreement, and (iii) all of the Borrower's or Triad
Nitrogen, Inc.'s indebtedness, obligations and liabilities to Harris with
respect to the Existing L/Cs shall be deemed to be Reimbursement Obligations of
the Borrower for all purposes of this Agreement.

       (b) Notwithstanding anything contained in any L/C Agreement to the
contrary:  (i) the Borrower shall pay fees in connection with each L/C as set
forth in Section 1.5(a) hereof, (ii) except as otherwise provided in Section
3.4(c) hereof, before the occurrence of a Potential Default or an Event of
Default, Harris will not call for the funding by the Borrower of any amount
under an L/C issued for the Borrower's account, or for any other form of
collateral security for the Borrower's obligations in connection with such L/C,
before being presented with a drawing thereunder, and (iii) if Harris is not
timely reimbursed for the amount of any drawing under an L/C on the date such
drawing is paid, the Borrower's obligation to reimburse Harris for the amount of
such drawing shall bear interest as specified in Section 1.6 hereof.  If Harris
issues any L/C with an expiration date that is automatically extended unless
Harris gives written notice that the expiration date will not so extend beyond
its then scheduled 
<PAGE>
 
expiration date, Harris will give such written notice of non-renewal before the
time necessary to prevent such automatic extension if before such required
notice date (i) the expiration date of such L/C if so extended would be more
than one year from the then scheduled expiration date of such L/C or after the
Termination Date, (ii) the Revolving Credit Commitments have been terminated, or
(iii) an Event of Default exists and the Required Banks have given Harris
instructions not to so permit the extension of the expiration date of such L/C.

       (c) The Administrative Agent shall give prompt telephone, telex, or
telecopy notice to each Bank of each issuance of, or amendment to, an L/C
specifying the effective date of the L/C or amendment, the amount, the
beneficiary, and the expiration date of the L/C, in each case as established
originally or through the relevant amendment, as applicable, the account party
or parties for the L/C, each Bank's pro rata participation in such L/C and
whether the Administrative Agent has classified the L/C as a commercial,
performance, or financial letter of credit for regulatory reporting purposes.

       Section 1.6. Reimbursement Obligation. The Borrower is obligated, and
hereby unconditionally agrees, to pay in immediately available funds to Harris
for the account of Harris and the Banks who are participating in L/Cs pursuant
to Section 1.8 hereof the face amount of each draft drawn and presented under an
L/C issued by Harris hereunder for the Borrower's account (the obligation of the
Borrower under this Section 1.6 with respect to any L/C is a "Reimbursement
Obligation"). If at any time the Borrower fails to pay any Reimbursement
Obligation when due, the Borrower shall be deemed to have automatically
requested a Revolving Credit Loan from the Banks hereunder, as of the maturity
date of such Reimbursement Obligation, the proceeds of which Loan shall be used
to repay such Reimbursement Obligation. Such Loan shall only be made if all of
the conditions precedent set forth in Section 6.2 of this Agreement have been
satisfied. If such Loan is not made by the Banks for any reason, the unpaid
amount of such Reimbursement Obligation shall be due and payable to Harris for
the pro rata benefit of the Banks upon demand and shall bear interest at the
rate of interest specified in Section 1.3(a), unless an Event of Default has
occurred then the rate of interest specified in Section 1.3(d)(i) hereof.

       Section 1.7.  Manner of Borrowing Revolving Credit Loans and Swingline
Loans.  (a) The Borrower shall give telephonic, telex or telecopy notice to the
Administrative Agent (which notice, if telephonic, shall be promptly confirmed
in writing) no later than (i) 12:00 Noon (Chicago time) on the date the Banks
are requested to make each Borrowing of Base Rate Loans, (ii) 12:00 Noon
(Chicago time) on the date at least three (3) Business Days prior to the date of
(A) each Borrowing of Eurodollar Loans which the Banks are requested to make or
continue, and (B) the conversion of any Borrowing of Base Rate Loans into a
Borrowing of Eurodollar Loans, and (iii) 12:00 Noon (Chicago time) on the date
the Borrower requests the Administrative Agent to make a Swingline Loan
hereunder.  Each such notice shall be irrevocable and shall specify the date of
the Borrowing requested (which shall be a Business Day), the amount of such
Borrowing, whether the Borrowing is to be made available by means of Base Rate
Loans or Eurodollar Loans and, with respect to a Borrowing of Eurodollar Loans,
the Interest Period applicable thereto; provided, that in no event shall the
principal amount of any requested Revolving Credit Loan plus the aggregate
principal or face amount, as appropriate, of all Loans, L/Cs, and unpaid
Reimbursement Obligations outstanding hereunder exceed the Revolving Credit
Commitments as such 
<PAGE>
 
amounts may be reduced pursuant to Section 3.5 of this Agreement. The Borrower
agrees that the Administrative Agent may rely on any such telephonic, telex or
telecopy notice given by any person who the Administrative Agent reasonably
believes is authorized to give such notice without the necessity of independent
investigation and in the event any notice by such means conflicts with the
written confirmation, such notice shall govern if the Administrative Agent or
any Bank has acted in reliance thereon. The Administrative Agent shall, on the
day any such notice is received by it, give prompt telephonic, telex or telecopy
(if telephonic, to be confirmed in writing within one Business Day) notice of
the receipt of notice from the Borrower hereunder to each of the Banks.

       (b) Subject to the provisions of Section 6 hereof, the proceeds of each
Borrowing of Revolving Credit Loans and of each Swingline Loan shall be made
available to the Borrower at the principal office of the Administrative Agent in
Chicago, Illinois, by depositing immediately available funds into an account
maintained by the Borrower with the Administrative Agent, on the date such
Borrowing is requested to be made, except to the extent such Borrowing
represents (i) a refinancing of a Reimbursement Obligation, in which case the
proceeds of such Borrowing shall be applied to the payment of the relevant
unpaid Reimbursement Obligation, or (ii) a refunding loan, in which case the
proceeds of such Borrowing shall be applied to the payment of the relevant
Swingline Loans pursuant to Section 1.2(b) hereof.  Not later than 3:00 p.m.
Chicago time, on the date specified for any Borrowing of Revolving Credit Loans
to be made hereunder, each Bank shall make its Loan comprising part of such
Borrowing available to the Borrower in immediately available funds at the
principal office of the Administrative Agent, except as otherwise provided above
with respect to paying any outstanding Reimbursement Obligation or Swingline
Loan.

       (c) Unless the Administrative Agent shall have been notified by a Bank
prior to the date of a Revolving Credit Loan to be made by such Bank (which
notice shall be effective upon receipt) that such Bank does not intend to make
the proceeds of such Revolving Credit Loan available to the Administrative
Agent, the Administrative Agent may assume that such Bank has made such proceeds
available to the Administrative Agent on such date and the Administrative Agent
may in reliance upon such assumption (but shall not be required to) make
available to the Borrower a corresponding amount.  If such corresponding amount
is not in fact made available to the Administrative Agent by such Bank, the
Administrative Agent shall be entitled to receive such amount on demand from
such Bank (or, if such Bank fails to pay such amount forthwith upon such demand,
to recover such amount, together with interest thereon at the rate otherwise
applicable thereto under Section 1.3 hereof, from the Borrower) together with
interest thereon in respect of each day during the period commencing on the date
such amount was made available to the Borrower and ending on the date the
Administrative Agent recovers such amount, at a rate per annum equal to the
effective rate charged to the Administrative Agent for overnight Federal funds
transactions with member banks of the Federal Reserve System for each day, as
determined by the Administrative Agent (or, in the case of a day which is not a
Business Day, then for the preceding Business Day) (the "Fed Funds Rate").
Nothing in this Section 1.7(c) shall be deemed to permit any Bank to breach its
obligations to make Revolving Credit Loans under the Revolving Credit, or to
limit the Borrower's claims against any Bank for such breach.
<PAGE>
 
       Section 1.8. Participation in L/Cs. (a) Each of the Banks will
acquire, without recourse, representation or warranty, a risk participation in
each L/C upon the issuance thereof ratably in accordance with its Commitment
Percentage.  In the event any Reimbursement Obligation is not immediately paid
by the Borrower pursuant to Section 1.6 hereof, each Bank will pay to Harris
funds in an amount equal to such Bank's Commitment Percentage of the unpaid
amount of such Reimbursement Obligation.  If the Banks fund Harris with respect
to any Reimbursement Obligation that is not paid when due by the Borrower as
described above, all of the Banks may elect to treat such funding as additional
Revolving Credit Loans to the Borrower hereunder rather than a purchase of
participations by the Banks in the related L/Cs held by Harris.  The obligation
of the Banks to Harris under this Section 1.8 shall be absolute and
unconditional and shall not be affected or impaired by any Event of Default or
Potential Default which may then be continuing hereunder.  Harris shall notify
each Bank by telephone of its Commitment Percentage of such unpaid Reimbursement
Obligation.  If such notice has been given to each Bank by 12:00 Noon, Chicago
time, each Bank agrees to put Harris in immediately available and freely
transferable funds on the same Business Day.  Funds shall be so made available
at the account designated by Harris in such notice to the Banks.  Upon the
election by the Banks to treat such funding as additional Revolving Credit Loans
hereunder and payment by each Bank, such Loans shall bear interest in accordance
with Section 1.3(a) hereof.  Harris shall share with each Bank its Commitment
Percentage of each payment of a Reimbursement Obligation (whether of principal
or interest) and any L/C Participation Fee payable by the Borrower.  Any such
amount shall be promptly remitted to the Banks when and as received by Harris
from the Borrower.  The L/C Issuance Fee and L/C Administration Fee shall be
solely for Harris' account and shall not be shared by the other Banks.

       (b) The Banks shall, ratably in accordance with their respective
Commitment Percentages, indemnify Harris (to the extent not reimbursed by the
Borrower) against any cost, expense (including reasonable counsel fees and
disbursements), claim, demand, action, loss or liability (except such as result
from Harris' gross negligence or willful misconduct) that Harris may suffer or
incur in connection with any L/C.  The obligations of the Banks under this
Section 1.8(b) and all other parts of this Section 1.8 shall survive termination
of this Agreement and of all L/C Agreements, and all drafts or other documents
presented in connection with drawings thereunder.

       Section 1.9. Capital Adequacy. If, after the date hereof, any Bank
or the Administrative Agent shall have determined in good faith that the
adoption of any applicable law, rule or regulation regarding capital adequacy,
or any change therein (including, without limitation, any revision in the Final
Risk-Based Capital Guidelines of the Board of Governors of the Federal Reserve
System (12 CFR Part 208, Appendix A; 12 CFR Part 225, Appendix A) or of the
Office of the Comptroller of the Currency (12 CFR Part 3, Appendix A), or in any
other applicable capital rules heretofore adopted and issued by any governmental
authority), or any change in the interpretation or administration thereof by any
governmental authority, central bank or comparable agency charged with the
interpretation or administration thereof, or compliance by any Bank (or its
Lending Office) with any request or directive regarding capital adequacy
(whether or not having the force of law) of any such authority, central bank or
comparable agency, has or would have the effect of reducing the rate of return
on such Bank's capital, or 
<PAGE>
 
on the capital of any corporation controlling such Bank, in each case as a
consequence of its obligations hereunder, to a level below that which such Bank
would have achieved but for such adoption, change or compliance (taking into
consideration such Bank's policies with respect to capital adequacy) by an
amount deemed by such Bank to be material, then from time to time if such Bank
is generally imposing payments for such reduction on its similarly situated
customers, within thirty (30) days after demand by such Bank (with a copy to the
Administrative Agent), the Borrower shall pay to such Bank such additional
amount or amounts as will compensate such Bank for such reduction.

Section 2. The Bid Facility.

     Section 2.1. The Bid Loans. At any time before the Termination Date, the
Borrower may request the Banks to offer to make uncommitted loans (each such
loan being hereinafter referred to as a "Bid Loan" and collectively as the "Bid
Loans") in the manner set forth in Sections 2.1 through 2.6 hereof and in
amounts such that the aggregate principal amount of the Total Outstandings
hereunder shall not exceed the sum of the Revolving Credit Commitments then in
effect after taking into account any Loans to be paid with such Bid Loans. The
Banks may, but shall have no obligation to, make such offers and the Borrower
may, but shall have no obligation to, accept any such offers in the manner set
forth in Sections 2.1 through 2.6 hereof. Each Bank may offer to make Bid Loans
in any amount (whether greater than, equal to, or less than its Revolving Credit
Commitment), subject to the limitation that the aggregate principal amount of
the Total Outstandings under this Agreement may not at any time exceed the sum
of the Revolving Credit Commitments then in effect. Bid Loans may either bear
interest at a stated rate per annum ("Stated Rate Bid Loans") or at a margin
(the "Bid Margin") over or under the Adjusted Eurodollar Rate ("Eurodollar Bid
Loans"); provided that there may be no more than five different Interest Periods
for Bid Loans outstanding at the same time and that no Bid Loan may mature after
the Termination Date.

     Section 2.2. Requests for Bid Loans.

     (a) Requests and Confirmations.  In order to request a Borrowing of Bid
Loans (a "Bid Loan Request") the Borrower shall give telephonic, telex or
telecopy notice to the Administrative Agent by no later than 1:00 p.m. (Chicago
time) on the date at least one Business Day in the case of Stated Rate Bid
Loans, and three Business Days in the case of Eurodollar Bid Loans, before the
date of the requested Bid Borrowing (the "Borrowing Date").  Each such request
shall be followed on the same day by a duly completed Bid Loan Request
Confirmation, delivered by telecopier or other means of facsimile communication,
substantially in the form of Exhibit C hereto or otherwise containing the
information required by this Section, to be received by the Administrative Agent
no later than 1:30 p.m. (Chicago time).  Bid Loan Request Confirmations that do
not conform substantially to the format of Exhibit C may be rejected by the
Administrative Agent, and the Administrative Agent shall give telephonic notice
to the Borrower of such rejection promptly after it determines that the Bid Loan
Request Confirmation does not substantially conform to the format of Exhibit C.
Bid Loan Requests shall in each case refer to this 
<PAGE>
 
Agreement and specify (i) the proposed Borrowing Date (which must be a Business
Day), (ii) the aggregate principal amount thereof (which shall not be less than
$5,000,000 and thereafter in integral multiples of $1,000,000) and (iii) the
proposed Interest Period thereof.

       (b) Invitation to Bid.  Upon receipt by the Administrative Agent of a Bid
Loan Request Confirmation that conforms substantially to the format of Exhibit C
hereto or is otherwise acceptable to the Administrative Agent, the
Administrative Agent shall, by telephone, promptly confirmed by a telecopy or
other form of facsimile communication in the form of Exhibit D hereto, invite
each Bank to bid, on the terms and conditions of this Agreement, to make Bid
Loans pursuant to the Bid Loan Request no later than 3:00 p.m. (Chicago time) on
the date the Administrative Agent receives such Bid Loan Request.

       (c) Bids.  Each Bank may, in its sole discretion, offer to make a Bid
Loan or Bid Loans (a "Bid") to the Borrower responsive to the Bid Loan Request.
Each Bid by a Bank must be received by the Administrative Agent by telephone not
later than 8:45 a.m. (Chicago time) on the Business Day following the date the
Administrative Agent receives a Bid Loan Request from the Borrower (the "Auction
Date"), promptly confirmed in writing by a duly completed Confirmation of Bid
delivered by telecopier or other means of facsimile communication substantially
in the form of Exhibit E hereto, to be received by the Administrative Agent on
the same day; provided, however, that any Bid made by the Administrative Agent
must be made by telephone to the Borrower by no later than fifteen minutes prior
to the time that Bids from the other Banks are required to be received.  Each
Bid and each Confirmation of Bid shall refer to this Agreement and specify (i)
the principal amount of each Bid Loan that the Bank is willing to make to the
Borrower and the type of Bid Loan (i.e., Stated Rate or Eurodollar), (ii) the
interest rate (which shall be computed on the basis of a 360-day year and actual
days elapsed and, in the case of a Eurodollar Bid Loan, shall be expressed in
terms of the Bid Margin to be added to or subtracted from the Adjusted
Eurodollar Rate for the Interest Period to be applicable to such Eurodollar Bid
Loan) at which the Bank is prepared to make each Bid Loan and (iii) the Interest
Period applicable thereto.  The Administrative Agent shall reject any Bid if
such Bid (i) does not specify all of the information specified in the
immediately preceding sentence, (ii) contains any qualifying, conditional, or
similar language, (iii) proposes terms other than or in addition to those set
forth in the Bid Loan Request to which it responds, or (iv) is received by the
Administrative Agent later than the times provided for above.  Any Bid submitted
by a Bank pursuant to this Section 2.2 shall be irrevocable and shall be
promptly confirmed by a telecopy or other form of facsimile communication in the
form of Exhibit E, provided that in all events the telephone Bid received by the
Administrative Agent shall be binding on the relevant Bank and shall not be
altered, modified, or in any other manner affected by any inconsistent terms
contained in, or terms missing from, the Bank's Confirmation of Bid.  Each offer
contained in a Bid to make a Bid Loan in a certain amount, at a certain interest
rate, and for a certain Interest Period is referred to herein as an "Offer".

       Section 2.3. Notice of Bids; Advice of Rate. The Administrative Agent
shall give telephonic notice to the Borrower of the number of Bids made, the
terms of the Offers contained in such Bids (including the interest rate(s) and
Interest Period(s) applicable to each Bid, the maximum principal amount bid at
each interest rate for each Interest Period, and the identity of the Bank making
such Bid), 
<PAGE>
 
such notice to be given by 9:15 a.m. (Chicago time) on the Auction Date. The
Administrative Agent shall send a written summary of all Bids received by it to
the Borrower by 2:00 p.m. (Chicago time) on the same day. The interest rates
quoted for Eurodollar Bid Loans shall be expressed in terms of the Bid Margin to
be added to or subtracted from the Adjusted Eurodollar Rate to be applicable to
such Bid Loan.

       Section 2.4. Acceptance or Rejection of Bids. The Borrower may in its
sole and absolute discretion, subject only to the provisions of this Section,
irrevocably accept or reject any Offer contained in a Bid. No later than the
later of 9:45 a.m. (Chicago time) or 30 minutes after receipt of telephonic
notice of bids on the Auction Date, the Borrower shall give telephonic notice to
the Administrative Agent of whether and to what extent it has decided to accept
or reject any or all of the Offers contained in the Bids made in response to the
related Bid Loan Request, which notice shall be promptly confirmed by telecopier
or other form of facsimile communication to be received by the Administrative
Agent on the proposed Borrowing Date; provided, however, that (a) the Borrower
shall accept Offers for any of the maturities specified by the Borrower in the
related Bid Loan Request Confirmation solely on the basis of ascending interest
rates for each such Interest Period for each Stated Rate Bid Loan or Eurodollar
Bid Loan as the case may be for such Interest Period, (b) if the Borrower
declines to borrow, or if it is restricted by any other condition hereof from
borrowing, the maximum principal amount of Bid Loans in respect of which Offers
at a particular interest rate for a particular Interest Period have been made,
then the Borrower shall accept a pro rata portion of each such Offer, based as
nearly as possible on the ratio of the maximum aggregate principal amounts of
Bid Loans for which each such Offer was made by each Bank (provided that, if the
available principal amount of Bid Loans to be so allocated is not sufficient to
enable Bid Loans to be so allocated to each relevant Bank in integral multiples
of $1,000,000, then the Borrower may round allocations up or down in integral
multiples not less than $100,000 as it shall deem appropriate), (c) the
aggregate principal amount of all Offers accepted by the Borrower shall not
exceed the maximum amount contained in the related Bid Loan Request
Confirmation, and (d) no Offer of a Bid Loan shall be accepted in a principal
amount less than $1,000,000 and thereafter in integral multiples of $500,000
(provided that such Offer may be rounded up or down as provided for in (b)
above). Any telephone notice given by the Borrower pursuant to this Section
shall be irrevocable and shall not be altered, modified, or in any other manner
affected by any inconsistent terms contained in, or terms missing from, any
written confirmation of such notice.

       Section 2.5.  Notice of Acceptance or Rejection of Bids.

       (a) Notice to Banks Making Successful Bids.  The Administrative Agent
shall give telephonic notice to each Bank if any of the Offers contained in its
Bid have been accepted (including the amount, the applicable interest rate and
Interest Period for each accepted Offer) no later than 10:15 a.m. (Chicago time)
on the Auction Date, and each successful bidder will thereupon become bound,
subject to Section 6 and the other applicable conditions hereof, to make the Bid
Loan(s) in respect of which its Offer has been accepted.  As soon as practicable
thereafter the Administrative Agent shall send a Notice of Acceptance 
<PAGE>
 
of Bid substantially in the form of Exhibit F hereto to each such successful
bidder; provided, however, that failure to give such Notice of Acceptance shall
not affect the obligation of such successful bidder to disburse its Bid Loans as
herein required.

       (b) Notice to all Banks.  As soon as practicable after each Borrowing
Date for Bid Loans, the Administrative Agent shall notify each Bank (whether or
not its Bid or its Bids were successful) of the aggregate amount of Bid Loans
advanced pursuant to the relevant Bid Loan Request on such Borrowing Date, the
maturities thereof, and the lowest and highest interest rates at which Bid Loans
were made for each maturity.

       (c) Disbursement of Bid Loans.  Not later than 1:30 p.m. (Chicago time)
on the Borrowing Date for each Borrowing of a Bid Loan(s), each Bank bound to
make a Bid Loan(s) in accordance with Section 2.5(a) shall, subject to Section 6
and the other applicable conditions hereof, make available to the Administrative
Agent the principal amount of each such Bid Loan in immediately available funds
at the Administrative Agent's principal office in Chicago, Illinois.  The
Administrative Agent shall promptly thereafter make available to the Borrower
like funds as received from each Bank, at such office of the Administrative
Agent in Chicago, Illinois.

       (d) Interest on Bid Loans.  The Borrower shall pay interest on the unpaid
principal amount of each Bid Loan from the applicable Borrowing Date to the
maturity thereof at the rate of interest applicable to such Bid Loan as
determined pursuant to the above provisions (calculated on the basis of a 360
day year and the actual number of days elapsed) payable on the last day of the
Interest Period applicable to such Bid Loan and at maturity (whether by
acceleration or otherwise), and, if the applicable Interest Period is longer
than 90 days, on each day occurring every 90 days after the date such Loan is
made.

       Section 2.6. Telephonic Notice. Each Bank's telephonic notice to the
Administrative Agent of its Bid pursuant to Section 2.2(c) hereof, and the
Borrower's telephonic acceptance of any Offer contained in a Bid pursuant to
Section 2.4 hereof, shall be irrevocable and binding on such Bank and the
Borrower and shall not be altered, modified, or in any other manner affected by
any inconsistent terms contained in, or missing from, any telecopy or other
confirmation of such telephonic notice.  It is understood and agreed by the
parties hereto that the Administrative Agent shall be entitled to act (or to
fail to act) hereunder in reasonable reliance on its records of any telephonic
notices provided for herein and that the Administrative Agent shall not incur
any liability to any Person in so doing if its records conflict with any
telecopy or other confirmation of a telephone notice or otherwise, provided that
the Administrative Agent has acted (or failed to act) in good faith.  It is
further understood and agreed by the parties hereto that the times of day as set
forth in this Section 2.6 are for the convenience of all the parties for
providing notices and that no party shall incur any liability or other
responsibility for any failure to provide such notices within the specified
times; provided, however, that the Administrative Agent shall have no obligation
to notify the Borrower of any Bid received by it later than 8:45 a.m. (Chicago
time) on the Auction Date, and no acceptance by the Borrower of any Offer
contained in such a Bid shall be effective to bind any Bank to make a Bid Loan,
nor shall the Administrative Agent be under any 
<PAGE>
 
obligation to notify any Person of an acceptance, if notice of such acceptance
is received by the Administrative Agent later than the later of 9:45 a.m.
(Chicago time) or 30 minutes after receipt of telephonic notice of bids on the
Auction Date.

Section 3.  The Notes, Fees, Prepayments, Terminations and Application of
            Payments.

       Section 3.1. The Notes.  All Loans made by each Bank to the Borrower
hereunder shall be evidenced by a single Revolving Credit Note of the Borrower
substantially in the form of Exhibit A hereto (individually, a "Revolving Note"
or "Note" and together, the "Revolving Notes" or "Notes") payable to the order
of such Bank, but the aggregate principal amount of indebtedness evidenced by
such Revolving Note at any time shall be, and the same is to be determined by,
the aggregate principal amount of all Loans made by such Bank to the Borrower
pursuant hereto on or prior to the date of determination less the aggregate
amount of principal repayments on such Loans received by or on behalf of such
Bank on or prior to such date of determination.  Each Revolving Note shall be
dated as of the execution date of this Agreement, shall be delivered
concurrently herewith, and shall be expressed to mature on the Termination Date
and to bear interest as provided in Sections 1.2, 1.3 and 2 hereof.  Each Bank
shall record on its books or records or on a schedule to its Revolving Note the
amount of each Loan made by it hereunder and all payments of principal and
interest and the principal balance from time to time outstanding, provided that
prior to any transfer of such Revolving Note all such amounts shall be recorded
on a schedule to such Revolving Note.  The record thereof, whether shown on such
books or records or on a schedule to the Revolving Note, shall be prima facie
evidence as to all such amounts; provided, however, that the failure of any Bank
to record any of the foregoing shall not limit or otherwise affect the
obligation of the Borrower to repay all Loans made hereunder together with
accrued interest thereon.  Upon the request of any Bank, the Borrower will
furnish a new Revolving Note to such Bank to replace its outstanding Revolving
Note and at such time the first notation appearing on the schedule on the
reverse side of, or attached to, such Revolving Note shall set forth the
aggregate unpaid principal amount of all Loans then outstanding from such Bank.
Such Bank will cancel the outstanding Revolving Credit Note upon receipt of the
new Revolving Note.

       Section 3.2.  Facility Fee.  For the period from the date hereof to
and including the Termination Date, or such earlier date on which the Revolving
Credit is terminated in whole pursuant to Section 3.5 hereof, the Borrower shall
pay to the Administrative Agent for the account of the Banks a facility fee with
respect to the Revolving Credit at the rate per annum (computed on a basis of a
year of 365/366 days for the actual number of days elapsed) equal to the
Applicable Margin in effect from time to time of the maximum amount of the
Revolving Credit Commitments, calculated without regard to whether any credit is
available or outstanding under the Revolving Credit (determined in each case
after giving effect to any reductions thereof as specified in Section 3.5
hereof).  Such fee shall be payable quarterly in arrears on the last day of each
March, June, September and December commencing on the last day of December,
1997, and on the Termination Date, unless the Revolving Credit is terminated in
<PAGE>
 
whole on an earlier date, in which event the fees for the period from the date
of the last payment made pursuant to this Section 3.2 through the effective date
of such termination in whole shall be paid on the date of such earlier
termination in whole.

       Section 3.3.  Agent's Fees.  The Borrower shall pay to and for the
sole account of the appropriate Agent such fees as the Borrower and such Agent
may agree upon in writing from time to time.  Such fees shall be in addition to
any fees and charges the Agents may be entitled to receive under the other Loan
Documents.

       Section 3.4.  (a)  Optional Prepayments of Base Rate Loans.  The
Borrower shall have the privilege of prepaying without premium or penalty and in
whole or in part (but if in part, then in a minimum principal amount of
$5,000,000 or such greater amount which is an integral multiple of $1,000,000)
any Borrowing of Base Rate Loans at any time upon prior telecopy or telephonic
notice from the Borrower to the Administrative Agent on or before 11:00 a.m.
(Chicago time) on the Business Day of such prepayment. Any amount prepaid under
the Revolving Credit may, subject to the terms and conditions of this Agreement,
be borrowed, repaid and borrowed again.

       (b) Optional Prepayments of Swingline Loans.  The Borrower may prepay any
borrowing of Swingline Loans, upon telephonic notice (which shall be promptly
confirmed in writing by facsimile communication, telex or telegraph) by no later
than 11:00 a.m. (Chicago time) on the date of such prepayment from the Borrower
to the Administrative Agent, such prepayment to be made by the payment of the
principal amount to be prepaid and accrued interest thereon and any compensation
required by Section 9.4 hereof, if applicable; provided, however, that any such
prepayment shall be in a principal amount of no less than $250,000 or such
greater amount which is an integral multiple of $100,000, and after giving
effect to any such prepayment the outstanding principal amount of any such
borrowing of Swingline Loans prepaid in part shall not be less than $250,000 or
such greater amount which is an integral multiple of $100,000.

       (c) Optional Prepayments of Eurodollar Loans.  The Borrower may prepay
any borrowing of Eurodollar Loans, upon telephonic notice (which shall be
promptly confirmed in writing by facsimile communication, telex or telegraph) by
no later than 11:00 a.m. (Chicago time) on the date of such prepayment from the
Borrower to the Administrative Agent, such prepayment to be made by the payment
of the principal amount to be prepaid and accrued interest thereon and any
compensation required by Section 9.4 hereof, if applicable; provided, however,
that any such prepayment shall be in a principal amount of no less than
$10,000,000 or such greater amount which is an integral multiple of $1,000,000,
and after giving effect to any such prepayment the outstanding principal amount
of any such borrowing of Eurodollar Loans prepaid in part shall not be less than
$10,000,000 or such greater amount which is an integral multiple of $1,000,000.

       (d) Mandatory Prepayments of Excess Borrowings.  If at any time the Total
Outstandings hereunder shall exceed the Revolving Credit Commitments, the
Borrower shall immediately prepay Loans and Reimbursement Obligations
outstanding for the Borrower's account and, if necessary, pledge cash collateral
to the Administrative Agent to secure outstanding L/Cs issued for the Borrower's
account, in an amount equal to such excess.
<PAGE>
 
       Section 3.5. Revolving Credit Termination. The Borrower shall have
the right at any time upon 5 days' prior notice to the Banks to terminate the
Revolving Credit in whole or in part (but if in part in a minimum principal
amount of $10,000,000 or such greater amount which is an integral multiple of
$5,000,000); provided, however, that the Borrower may not terminate any portion
of the Revolving Credit which represents outstanding Revolving Credit
Obligations unless the Borrower contemporaneously prepays the same or, with
respect to any outstanding L/Cs, pledges cash collateral to the Administrative
Agent to secure the same.

       Section 3.6.  Place and Application of Payments.  All payments by the
Borrower hereunder shall be made to the Administrative Agent at its office at
111 West Monroe Street, Chicago, Illinois 60690 and in immediately available
funds, prior to 12:00 noon on the date of such payment.  All such payments shall
be made without setoff or counterclaim and without reduction for, and free from,
any and all present and future levies, imposts, duties, fees, charges,
deductions withholdings, restrictions or conditions of any nature imposed by any
government or any political subdivision or taxing authority thereof.  Any
payments received after 12:00 noon Chicago time (or after any later time the
Banks may otherwise direct) shall be deemed received upon the following Business
Day.  The Administrative Agent shall remit to each Bank its proportionate share
of each payment of principal, interest and facility fees received by the
Administrative Agent by 3:00 P.M. Chicago time on the same day of its receipt
and its proportionate share of each such payment received by the Administrative
Agent after 12:00 noon on the Business Day following its receipt by the
Administrative Agent.  In the event the Administrative Agent does not remit any
amount to any Bank when required by the preceding sentence, the Administrative
Agent shall pay to such Bank interest on such amount until paid at a rate per
annum equal to the Fed Funds Rate.  The Borrower hereby authorizes the
Administrative Agent to automatically debit its designated account with Harris
for any principal, interest and fees when due under the Notes, any L/C
Agreements or this Agreement and to transfer the amount so debited from such
account to the Administrative Agent for application as herein provided.

Section 4. Definitions.

       Section 4.1.  Certain Definitions.  The terms hereinafter set forth
when used herein shall have the following meanings:

       "Adjusted Eurodollar Rate" means a rate per annum determined pursuant to
the following formula:

       Adjusted Eurodollar Rate  =             Eurodollar Rate
                                     -----------------------------------
                                          100% - Reserve Percentage

       "Administrative Agent" shall have the meaning specified in the first
paragraph of this Agreement.

       "Affiliate" shall mean, for any Person, any other Person (including all
directors and officers of such Person) that directly or indirectly controls, or
is under common control with, or is controlled by, 
<PAGE>
 
such Person. As used in this definition, "control" means the power, directly or
indirectly, to direct or cause the direction of management or policies of a
Person (through ownership of voting securities, by contract or otherwise),
provided that, in any event for purposes of the definition any Person that owns
directly or indirectly 10% or more of the securities having ordinary voting
power for the election of directors of a corporation or 10% or more of the
partnership or other ownership interests of any other Person will be deemed to
control such corporation or other Person.

     "Agents" shall mean the Administrative Agent and the Syndication Agent.

     "Agreement" shall mean this Credit Agreement as supplemented and amended
from time to time.

     "Annualized Average EBIT" shall mean with reference to any fiscal quarter,
an amount equal to the EBIT of the Borrower and its Subsidiaries, each
calculated on a consolidated basis in accordance with generally accepted
accounting principles, for the eight consecutive fiscal quarters ending with
such fiscal quarter divided by two; provided, that if the Borrower or any of its
Subsidiaries shall have acquired any business, Property or Person during such
eight fiscal quarters (whether before, on or after the date hereof), EBIT shall,
to the extent the Borrower shall have delivered audited financial statements
(or, if audited financial statements are not available to the Borrower,
unaudited financial statements in form reasonably satisfactory to the
Administrative Agent) for the acquired business, Property or Person for such
period, be adjusted to reflect on a pro forma basis EBIT for such business,
Property or Person as if such business, Property or Person had been acquired at
the beginning of such period.

     "Applicable Margin" shall mean, with respect to the Facility Fee and each
type of Loan described below, the rate of interest per annum shown below for the
range of Pricing Ratio specified below:
<TABLE>
<CAPTION>
                       Level I        Level II               Level III                 Level IV                  Level V
--------------------------------------------------------------------------------------------------------------------------
<S>                  <C>            <C>            <C>     <C>             <C>      <C>              <C>      <C>
Pricing                 *0.75x       ***0.75x       and     ***1.50x        and       ***2.25x        and       **3.00x
Ratio                                  *1.50x                 *2.25x                  ***3.00x
--------------------------------------------------------------------------------------------------------------------------
Fed Funds Rate               .15%           .25%                   .475%                     .675%                    1.00%
Loans
--------------------------------------------------------------------------------------------------------------------------
Base Rate Loans                0%             0%                      0%                        0%                     .25%
--------------------------------------------------------------------------------------------------------------------------
Eurodollar Loans             .15%           .25%                   .475%                     .675%                    1.00%
--------------------------------------------------------------------------------------------------------------------------
Facility Fee                 .10%           .12%                    .15%                      .20%                     .25%
--------------------------------------------------------------------------------------------------------------------------
</TABLE>
------------------------------
*    Less than
**   More than
***  Less than or equal to

     The Applicable Margins will be adjusted upon receipt of the Borrower's
quarterly Compliance Certificate or Pricing Ratio Certificate for the fiscal
quarter ended December 31, 1997 and at the close of 
<PAGE>
 
every fiscal quarter thereafter. Not later than 5 Business Days after receipt by
the Administrative Agent of the certificates called for by Section 7.4(c) or (f)
hereof for each fiscal quarter, the Administrative Agent shall determine the
Pricing Ratio for the applicable period and shall promptly notify the Borrower
and the Banks of such determination and of any change in the Applicable Margins
resulting therefrom. Any such change in the Applicable Margins shall be
effective as of the forty-fifth (45th) day following the close of each fiscal
quarter with respect to all Revolving Credit Loans and Swingline Loans
outstanding on such date, and such new Applicable Margins shall continue in
effect until the forty-fifth (45th) day following the close of the next
succeeding fiscal quarter. Each determination of the Pricing Ratio and
Applicable Margins by the Administrative Agent in accordance with this Section
shall be conclusive and binding on the Borrower and the Banks absent manifest
error. From the date hereof until the Applicable Margins are first adjusted
pursuant hereto, the Applicable Margins shall be those set forth in Level III
above.

     "Bank" and "Banks" shall have the meanings specified in the first paragraph
of this Agreement.

     "Base Rate" means for any day the rate of interest announced by Harris from
time to time as its prime commercial rate in effect on such day, with any change
in the Base Rate resulting from a change in said prime commercial rate to be
effective as of the date of the relevant change in said prime commercial rate
(the "Harris Prime Rate"), provided that if the rate per annum determined by
adding 1/2 of 1% to the rate at which Harris would offer to sell federal funds
in the interbank market on or about 10:00 A.M. (Chicago time) on any day (the
"Adjusted Fed Funds Rate") shall be higher than the Harris Prime Rate on such
day, then the Base Rate for such day and for the succeeding day which is not a
Business Day shall be such Adjusted Fed Funds Rate.  The determination of the
Adjusted Fed Funds Rate by the Administrative Agent shall be final and
conclusive provided it has acted in good faith in connection therewith.

     "Base Rate Loan" shall mean a Revolving Credit Loan which bears interest as
provided in Section 1.3(a) hereof.

     "Bid Loan" shall have the meaning specified in Section 2.1 hereof.

     "Borrower" shall have the meaning specified in the first paragraph of this
Agreement.

     "Borrowing" means the total of Loans (other than Swingline Loans) of a
single type made by the Banks to the Borrower on a single date and for a single
Interest Period.  Borrowings of Revolving Credit Loans are made ratably from the
Banks according to their Revolving Credit Commitments.  Borrowings of a Bid Loan
or Bid Loans are made from a Bank or Banks in accordance with the procedures of
Section 2 hereof.

     "Business Day" shall mean any day except Saturday or Sunday on which banks
are open for business in Chicago, Illinois, and, with respect to Eurodollar
Loans and Eurodollar Bid Loans, dealing in United States dollar deposits in
London, England and Nassau, Bahamas.
<PAGE>
 
     "Capitalized Lease" shall mean any lease or obligation for rentals which is
required to be capitalized on a consolidated balance sheet of a Person and its
Subsidiaries in accordance with generally accepted accounting principles,
consistently applied.

     "Capitalized Lease Obligation" shall mean the present discounted value of
the rental obligations under any Capitalized Lease.

     "Change of Control" shall mean the occurrence, after the date hereof, of
(i) any Person or two or more Persons acting in concert acquiring beneficial
ownership (within the meaning of Rule 13d-3 of the Securities and Exchange
Commission under the Securities Exchange Act of 1934, as amended), directly or
indirectly, of securities of the Borrower (or other securities convertible into
such securities) representing more than 20% of the combined voting power of all
securities of the Borrower entitled to vote in the election of directors; or
(ii) commencing after the date hereof, individuals who as of the date hereof
were directors of the Borrower ceasing for any reason to constitute a majority
of the Board of Directors of the Borrower unless the Persons replacing such
individuals were nominated by the Board of Directors of the Borrower; or (iii)
any Person or two or more Persons acting in concert acquiring by contract or
otherwise, or entering into a contract or arrangement which upon consummation
will result in its or their acquisition of, or control over, securities of the
Borrower (or other securities convertible into such securities) representing
more than 20% of the combined voting power of all securities of the Borrower
entitled to vote in the election of directors.

     "Commitment Percentage" shall have the meaning set forth in Section 1.1(b)
hereof.

     "Compliance Certificate" shall mean a Compliance Certificate in the form of
Exhibit H attached hereto.

     "Debt" of any Person shall mean as of any time the same is to be
determined, the aggregate (without duplication) of:

            (a) all indebtedness, obligations and liabilities with respect to
     borrowed money;

            (b) all guaranties, endorsements (other than any liability arising
     out of the endorsement of items for deposit or collection in the ordinary
     course of business) and other contingent obligations in respect of, or any
     obligations to purchase or otherwise acquire, indebtedness or securities of
     others or to purchase Property of others at the request or demand of any
     creditor of such Person;

            (c) all reimbursement and other obligations with respect to letters
     of credit (whether drawn or undrawn), banker's acceptances, customer
     advances and other extensions of credit whether or not representing
     obligations for borrowed money;
<PAGE>
 
            (d) the aggregate amount of Capitalized Lease Obligations;

            (e) all indebtedness and liabilities secured by any lien or any
     security interest on any Property or assets of such Person, whether or not
     the same would be classified as a liability on a balance sheet; and

            (f) all indebtedness, obligations and liabilities representing the
     deferred purchase price of Property, excluding trade payables incurred in
     the ordinary course of business not more than 90 days past due;

all computed and determined on a consolidated basis for such Person and its
Subsidiaries after the elimination of intercompany items in accordance with
generally accepted accounting principles consistent with those used in the
preparation of the audit report referred to in Section 5.2 hereof.

     "EBIT" means, for any Person and with reference to any period, Net Income
for such period plus all amounts deducted in arriving at such Net Income amount
in respect of (i) Interest Expense for such period, plus (ii) federal, state and
local income taxes for such period.

     "EBITDA" means, for any Person and with reference to any period, Net Income
for such period plus all amounts deducted in arriving at such Net Income amount
in respect of (i) Interest Expense for such period, plus (ii) federal, state and
local income taxes for such period, plus (iii) all amounts properly charged for
depreciation of fixed assets and amortization of intangible assets during such
period on the books of such Person and its Subsidiaries.

     "Environmental Laws" shall mean all federal, state and local environmental,
health and safety statutes and regulations, including without limitation all
statutes and regulations establishing quality criteria and standards for air,
water, land and toxic or hazardous wastes and substances.

     "ERISA" shall mean the Employee Retirement Income Security Act of 1974, as
amended.

     "Eurodollar Bid Loan" shall have the meaning specified in Section 2.1
hereof.

     "Eurodollar Loan" shall mean a Revolving Credit Loan which bears interest
as provided in Section 1.3(b) hereof.

     "Eurodollar Rate" shall mean for each Interest Period applicable to a
Eurodollar Loan or Eurodollar Bid Loan, (a) the LIBOR Index Rate for such
Interest Period, if such rate is available, and (b) if the LIBOR Index Rate
cannot be determined, the arithmetic average of the rates of interest per annum
(rounded upwards, if necessary, to nearest one hundred-thousandth of a
percentage point) at which deposits in U.S. dollars in immediately available
funds are offered to the Administrative Agent at 11:00 a.m. (London, England
time) two (2) Business Days before the beginning of such Interest Period by
three 
<PAGE>
 
(3) or more major banks in the interbank eurodollar market selected by the
Administrative Agent for a period equal to such Interest Period and in an amount
equal or comparable to the principal amount of the Eurodollar Loan or Eurodollar
Bid Loan scheduled to be made by the Administrative Agent or, in the case of a
Eurodollar Bid Loan, the applicable Bank (if other than the Administrative
Agent) during such Interest Period.

     "Event of Default" shall mean any event or condition identified as such in
Section 8.1 hereof.

     "Existing Agreements" shall have the meaning specified in Section 7.15
hereof.

     "Existing Banks" shall mean the lenders under each of the Existing
Agreements.

     "Farmland MissChem, Ltd." means that certain Trinidad limited liability
company equally owned by the Borrower and Farmland Industries, Inc. which was
formed to develop the Farmland MissChem Project.

     "Farmland MissChem Project" means that certain project commenced by
Farmland MissChem, Ltd. to develop an ammonia plant in Trinidad.

     "Farmland MissChem Project Contingent Obligations" means the contingent
obligations described on Exhibit J hereto.

     "Fed Funds Rate" shall have the meaning specified in Section 1.7(c) hereof.

     "Fed Funds Rate Loan" shall mean a Swingline Loan that bears interest as
provided in Section 1.3(c) hereof.

     "Fixed Fed Funds Rate" means with respect to each Interest Period
applicable to a Fed Funds Loan, the rate of interest per annum as determined by
the Administrative Agent at which term federal funds would be offered by the
Administrative Agent on the first day of such Interest Period to major banks in
the interbank market upon request by such major banks for a period equal to such
Interest Period and in an amount equal to the principal amount of the Fed Funds
Loan scheduled to be outstanding during such Interest Period.  Each
determination of the Fed Funds Rate made by the Administrative Agent in
accordance with this paragraph shall be conclusive and binding on the Borrower
except in the case of manifest error or willful misconduct.

     "Fixed Rate Loan" shall mean any Offered Rate Loan, Eurodollar Loan, Bid
Loan or Fed Funds Rate Loan.

     "Harris" shall have the meaning specified in the first paragraph of this
Agreement.
<PAGE>
 
     "Interest Coverage Ratio" shall mean, with reference to each fiscal quarter
of the Borrower and its Subsidiaries, the ratio of (x) Annualized Average EBIT
to (y) Interest Expense for the preceding four fiscal quarters.

     "Interest Expense" shall mean, for any Person and with reference to any
period, the sum of all interest charges (including imputed interest charges with
respect to Capitalized Lease Obligations, all amortization of debt discount and
expense and all fees relating to letters of credit accrued and all net
obligations pursuant to interest rate hedging agreements) of such Person and its
Subsidiaries for such period determined on a consolidated basis in accordance
with generally accepted accounting principles, consistently applied; provided,
that if the Borrower or any of its Subsidiaries shall have acquired any
business, Property or Person during such period (whether before, on or after the
date hereof), Interest Expense shall, to the extent the Borrower shall have
delivered audited financial statements (or, if audited financial statements are
not available to the Borrower, unaudited financial statements in form reasonably
satisfactory to the Administrative Agent) for the acquired business, Property or
Person for such period, be adjusted to reflect on a pro forma basis Interest
Expense for such business, Property or Person as if such business, Property or
Person had been acquired at the beginning of such period.

     "Interest Period" shall mean with respect to (a) any Eurodollar Loan, the
period used for the computation of interest commencing on the date the relevant
Eurodollar Loan is made, continued or effected by conversion and concluding on
the date one, two, three, six or twelve months thereafter as selected by the
Borrower in its notice as provided herein, (b) any Eurodollar Bid Loan, the
period used for the computation of interest commencing on the date the relevant
Eurodollar Bid Loan is made, continued or effected by conversion and concluding
on the date one, two, three, four, five or six months thereafter as selected by
the Borrower in its notice as provided herein, (c) any Offered Rate Loan, the
period used for the computation of interest commencing on the date of the
relevant Offered Rate Loan is made and concluding on the date 1 to 7 days
thereafter as agreed by the Administrative Agent and the Borrower, (d) any Fed
Funds Rate Loan, the period used for the computation of interest commencing on
the date of the relevant Fed Funds Rate Loan and concluding on the date 1 to 7
days thereafter as agreed by the Administrative Agent and the Borrower, and (e)
any Stated Rate Bid Loan, the period commencing on, as the case may be, the
creation, continuation or conversion date with respect to such Stated Rate Bid
Loan and ending one (1) to one hundred eighty (180) days thereafter as selected
by the Borrower in its notice as provided herein; provided that all of the
foregoing provisions relating to Interest Periods are subject to the following:

            (i) if any Interest Period would otherwise end on a day which is not
     a Business Day, that Interest Period shall be extended to the next
     succeeding Business Day, unless in the case of an Interest Period for a
     Eurodollar Loan or Eurodollar Bid Loan the result of such extension would
     be to carry such Interest Period into another calendar month in which event
     such Interest Period shall end on the immediately preceding Business Day;

            (ii) no Interest Period may extend beyond the Termination Date; and
<PAGE>
 
            (iii)  the interest rate to be applicable to each Loan for each
     Interest Period shall apply from and including the first day of such
     Interest Period to but excluding the last day thereof.

For purposes of determining an Interest Period, a month means a period starting
on one day in a calendar month and ending on a numerically corresponding day in
the next calendar month, provided, however, if an Interest Period begins on the
last day of a month or if there is no numerically corresponding day in the month
in which an Interest Period is to end, then such Interest Period shall end on
the last Business Day of such month.

     "Inventory" shall mean all raw materials, work in process, finished goods,
and goods held for sale or lease or furnished or to be furnished under contracts
of service in which any Borrower or any Subsidiary now has or hereafter acquires
any right.

     "L/C" shall have the meaning set forth in Section 1.5 hereof.

     "L/C Agreement" shall have the meaning set forth in Section 1.5 hereof.

     "L/C Administrative Fee" has the meaning specified in Section 1.5(a)
hereof.

     "L/C Issuance Fee" has the meaning specified in Section 1.5(a) hereof.

     "L/C Participation Fee" shall have the meaning specified in Section 1.5(a)
hereof.

     "Leverage Ratio" shall mean, as of any date of determination, the ratio of
(x) the sum of all Debt of the Borrower and its Subsidiaries (determined on a
consolidated basis) to (y) an amount equal to the EBITDA of the Borrower and its
Subsidiaries, each calculated on a consolidated basis in accordance with
generally accepted accounting principles, for the eight consecutive fiscal
quarters ending with such fiscal quarter divided by two; provided, that if the
Borrower or any of its Subsidiaries shall have acquired any business, Property
or Person during such eight fiscal quarters (whether before, on or after the
date hereof), EBITDA shall, to the extent the Borrower shall have delivered
audited financial statements (or, if audited financial statements are not
available to the Borrower, unaudited financial statements in form reasonably
satisfactory to the Administrative Agent) for the acquired business, Property or
Person for such period, be adjusted to reflect on a pro forma basis EBITDA for
such business, Property or Person as if such business, Property or Person had
been acquired at the beginning of such period.

     "LIBOR Index Rate" shall mean, for any Interest Period applicable to a
Eurodollar Loan, the rate per annum (rounded upwards, if necessary, to the next
higher one hundred-thousandth of a percentage point) for deposits in U.S.
Dollars for a period equal to such Interest Period, which appears on the
Telerate Page 3750 as of 11:00 a.m. (London, England time) on the day two
Business Days before the commencement of such Interest Period.

     "Loan" shall mean Revolving Credit Loans, Swingline Loans and Bid Loans,
and each of them singly, and the term "type" of Loan refers to its status as a
Fed Funds Rate Loan, an Offered Rate Loan, a Eurodollar Loan, Eurodollar Bid
Loan, a Base Rate Loan or Stated Rate Bid Loan.
<PAGE>
 
     "Loan Documents" shall mean this Agreement and any and all exhibits hereto,
the Notes and the L/C Agreements.

     "Net Income" means, for any Person and with reference to any period, the
net income of such Person and its Subsidiaries for such period determined on a
consolidated basis in accordance with generally accepted accounting principles,
consistently applied, but excluding in any event any items of extraordinary gain
or loss.

     "Net Tangible Assets" of the Borrower means, at any date, the gross book
value as shown by the accounting books and records of the Borrower of all
Property both real and personal of the Borrower and its Subsidiaries, determined
on a consolidated basis in accordance with generally accepted accounting
principles, (including appropriate deductions for any minority interests in
property of Subsidiaries of the Borrower) less (a) the gross book value of all
its licenses, patents, patent applications, copyrights, trademarks, trade names,
goodwill, non-compete agreements or organizational expenses and other like
intangibles, (b) unamortized Debt discount and expense, (c) all reserves for
depreciation, obsolescence, depletion and amortization of its Properties, and
(d) all other proper reserves against assets which in accordance with generally
accepted accounting principles should be provided in connection with the
business conducted by the Borrower or its Subsidiaries.

     "Note" and "Notes" shall have the meanings specified in Section 3.1 hereof.

     "Offered Rate Loan" shall mean a Swingline Loan that bears interest as
provided in Section 1.2(a) hereof.

     "PBGC" shall mean the Pension Benefit Guaranty Corporation.

     "Person" shall mean and include any individual, sole proprietorship,
partnership, limited liability company, joint venture, trust, unincorporated
organization, association, corporation, institution, entity, party or government
(whether national, federal, state, county, city, municipal, or otherwise,
including, without limitation, any instrumentality, division, agency, body or
department thereof).

     "Plan" shall mean any employee benefit plan covering any officers or
employees of a Borrower or any Subsidiary, any benefits of which are, or are
required to be, guaranteed by the PBGC.

     "Potential Default" shall mean any event or condition specified in Section
8.1 hereof which, with the lapse of time, or giving of notice, or both, would
constitute an Event of Default.

     "Pricing Ratio" shall mean, as of any date or determination, the ratio of
(x) the sum of all Debt of the Borrower and its Subsidiaries (determined on a
consolidated basis) to (y) EBITDA of the Borrower 
<PAGE>
 
and its Subsidiaries, each determined on a consolidated basis in accordance with
generally accepted accounting principles, for the four fiscal quarters ending on
such date of determination; provided, that if the Borrower or any of its
Subsidiaries shall have acquired any business, Property or Person during such
four fiscal quarters (whether before, on or after the date hereof), EBITDA
shall, to the extent the Borrower shall have delivered audited financial
statements (or, if audited financial statements are not available to the
Borrower, unaudited financial statements in form reasonably satisfactory to the
Administrative Agent) for the acquired business, Property or Person for such
period, be adjusted to reflect on a pro forma basis EBITDA for such business,
Property or Person as if such business, Property or Person had been acquired at
the beginning of such period.

     "Pricing Ratio Certificate" has the meaning specified in Section 7.4(f)
hereof.

     "Property" shall mean all assets and properties of any nature whatsoever,
whether real or personal, tangible or intangible, including without limitation
intellectual property.

     "Reimbursement Obligations" has the meaning specified in Section 1.6
hereof.

     "Rentals" shall mean and include all fixed rents (including as such all
payments which the lessee is obligated to make to the lessor on termination of
the lease or surrender of the Property to the extent such termination or
surrender occurs during the relevant period) payable by the Borrower or a
Subsidiary, as lessee or sublessee under a lease of real or personal property,
but shall be exclusive of any amounts required to be paid by the Borrower or a
Subsidiary (whether or not designated as rents or additional rents) on account
of maintenance, repairs, insurance, taxes and similar charges.  Fixed rents
under any so-called "percentage leases" shall be computed solely on the basis of
the minimum rents, if any, required to be paid by the lessee regardless of sales
volume or gross revenues.  Capitalized Lease Obligations shall be excluded from
the definition of Rentals for all purposes hereunder other than the use of the
term "rentals" in the definitions of Capitalized Lease and Capitalized Lease
Obligations.

     "Required Banks" shall mean any Bank or Banks which in the aggregate have
more than 50% of the Revolving Credit Commitments or, if at the time no
Revolving Credit Commitments are in effect, any Bank or Banks which in the
aggregate hold more than 50% of the aggregate unpaid principal balance of the
Loans and Reimbursement Obligations then outstanding.

     "Reserve Percentage" means the daily arithmetic average maximum rate at
which reserves (including, without limitation, any supplemental, marginal and
emergency reserves) are imposed on member banks of the Federal Reserve System
during the applicable Interest Period by the Board of Governors of the Federal
Reserve System (or any successor) under Regulation D on "eurocurrency
liabilities" (as such term is defined in Regulation D), subject to any
amendments of such reserve requirement by such Board or its successor, taking
into account any transitional adjustments thereto.  For purposes of this
definition, the Eurodollar Loans shall be deemed to be eurocurrency liabilities
as defined in Regulation D without benefit or credit for any prorations,
exemptions or offsets under Regulation D.  As of the date hereof, the Reserve
Percentage is zero.
<PAGE>
 
     "Restricted Payments" shall have the meaning specified in Section 7.8
hereof.

     "Revolving Credit" shall have the meaning specified in the first paragraph
of this Agreement.

     "Revolving Credit Commitment" and "Revolving Credit Commitments" shall have
the meanings specified in Section 1.1(b) hereof.

     "Revolving Credit Loan" and "Revolving Credit Loans" shall have the
meanings specified in Section 1.1(a) hereof.

     "Revolving Credit Obligations" shall have the meaning specified in Section
1.1(a) hereof.

     "Revolving Note" or "Revolving Notes" shall have the meanings specified in
Section 3.1 hereof.

     "Senior Notes" shall mean the Borrower's 7.25% Senior Notes due 2017 in the
original aggregate principal amount of $200,000,000, and Borrower's Senior Notes
to be hereafter issued in the original aggregate principal amount of up to
$100,000,000, to be governed by the same Indenture as the other Senior Notes
herein described.

     "Subsidiary" shall mean, for any Person, any corporation or other entity of
which more than fifty percent (50%) of the outstanding stock or comparable
equity interests having ordinary voting power for the election of the Board of
Directors of such corporation or similar governing body in the case of a non-
corporation (irrespective of whether or not, at the time, stock or other equity
interests of any other class or classes of such corporation or other entity
shall have or might have voting power by reason of the happening of any
contingency) is at the time directly or indirectly owned by such Person or by
one or more of its Subsidiaries.

     "Syndication Agent" shall have the meaning specified in the first paragraph
of this Agreement.

     "Tangible Net Worth" means, for any Person and at any time the same is to
be determined, the total shareholders' equity (including capital stock,
additional paid-in capital and retained earnings after deducting treasury stock
and excluding minority interests in Subsidiaries) which would appear on the
balance sheet of such Person and its Subsidiaries determined on a consolidated
basis in accordance with generally accepted accounting principles, consistently
applied, less the sum of the aggregate book value of all assets which would be
classified as intangible assets under generally accepted accounting principles,
consistently applied, including, without limitation, goodwill, patents,
trademarks, trade names, copyrights, franchises and deferred charges (including,
without limitation, unamortized debt discount and expense, organization costs
and deferred research and development expense, but excluding deferred taxes) and
similar assets and the write-up of assets above cost.
<PAGE>
 
     "Telerate Page 3750" shall mean the display designated as "Page 3750" on
the Telerate Service (or such other page as may replace Page 3750 on that
service or such other service as may be nominated by the British Bankers'
Association as the information vendor for the purpose of displaying British
Bankers' Association Interest Settlement Rates for U.S. Dollar deposits).

     "Termination Date" shall have the meaning set forth in Section 1.1(a)
hereof.

     "Total Assets" shall mean, at any time the same is to be determined, the
aggregate of all items which would be listed as an asset on a balance sheet of a
Person and its Subsidiaries determined on a consolidated basis in accordance
with generally accepted accounting principles.

     "Total Outstandings" shall mean the aggregate principal amount of all Loans
plus the aggregate principal amount of all unpaid Reimbursement Obligations plus
the maximum amount available to be drawn under all L/Cs outstanding under this
Agreement.

     Section 4.2.  Accounting Terms.  Any accounting term not otherwise
specifically defined in this Agreement shall have the meaning customarily given
to such term in accordance with generally accepted accounting principles,
consistently applied.  Where the character or amount of any asset or liability
or item of income or expense is required to be determined or any consolidation
or other accounting computation is required to be made for the purpose of this
Agreement, it shall be done in accordance with generally accepted accounting
principles, to the extent applicable, except where such principles are
inconsistent with the requirements of this Agreement.

Section 5. Representations and Warranties.

     The Borrower represents and warrants to the Banks as follows:

     Section 5.1.  Organization and Qualification; Non-Contravention.
The Borrower is duly organized, validly existing and in good standing under the
laws of the state of its incorporation, has full and adequate corporate power to
carry on its business as now conducted, is duly licensed or qualified in all
jurisdictions wherein the nature of its activities requires such licensing or
qualifying, except where the failure to be so licensed or qualified would not
result in a material adverse change in the Properties, business or operations of
the Borrower and its Subsidiaries taken as a whole, has full right, power and
authority to enter into this Agreement and the other Loan Documents to which it
is a party, to make the borrowings herein provided for, to execute and issue its
Notes in evidence thereof, and to perform each and all of the matters and things
herein and therein provided for; and this Agreement and the other Loan Documents
do not, nor does the performance or observance by the Borrower of any of the
matters or things provided for in the Loan Documents, contravene any provision
of law or any charter or by-law provision or any material covenant, indenture or
agreement of or affecting the Borrower or its Properties.
<PAGE>
 
     Section 5.2.  Financial Reports.  The Borrower has heretofore delivered to
each Bank a copy of the annual audit report as of June 30, 1997, and the
accompanying financial statements of the Borrower and its Subsidiaries and
unaudited financial statements of the Borrower and its Subsidiaries as of, and
for the interim period ending September 30, 1997.  Such financial statements
have been prepared in accordance with generally accepted accounting principles
(except for the omission of footnotes and subject to normal year-end audit
adjustments with respect to such unaudited statements) on a basis consistent,
except as otherwise noted therein, with that of the previous fiscal year or
period and fairly reflect in all material respects the financial position of the
Borrower and its Subsidiaries as of the dates thereof, and the results of its
operations for the periods covered thereby.  The Borrower and its Subsidiaries
have no material contingent liabilities other than as indicated on said
financial statements and since said date of September 30, 1997, there has been
no material adverse change in the condition, financial or otherwise, of the
Borrower or any Subsidiary, except those disclosed in writing to the Banks prior
to the date of this Agreement.

     Section 5.3. Litigation; Tax Returns; Approvals. Except as disclosed on
Schedule 5.3 hereto, there is no litigation, labor controversy or governmental
proceeding pending, nor to the knowledge of the Borrower threatened, against the
Borrower or any Subsidiary which could reasonably be expected to result in any
material adverse change in the Properties, business or operations of the
Borrower and its Subsidiaries taken as a whole. All federal, state and local
income tax returns for the Borrower and its Subsidiaries required to be filed
have been filed on a timely basis, and all amounts required to be paid as shown
by said returns have been paid. There are no pending or, to the Borrower's
knowledge, material threatened objections to or controversies in respect of the
United States federal, state or local income tax returns of the Borrower and its
Subsidiaries for any fiscal year. No authorization, consent, license, exemption
or filing or registration with any court or governmental department, agency or
instrumentality, is or will be necessary to the valid execution, delivery or
performance by the Borrower of the Loan Documents to which it is a party, except
such as have been previously obtained or where the failure to obtain such
authorization, consent, license, exemption or make such filing or registration
would not result in a material adverse change in the Properties, business or
operations of the Borrower and its Subsidiaries taken as a whole.

     Section 5.4. Regulation U. Neither the Borrower nor any Subsidiary
is engaged in the business of extending credit for the purpose of purchasing or
carrying margin stock (within the meaning of Regulation U of the Board of
Governors of the Federal Reserve System) and no part of the proceeds of any Loan
or other extension of credit hereunder will be used to purchase or carry any
margin stock (other than the Borrower's common stock) or to extend credit to
others for such a purpose.
<PAGE>
 
       Section 5.5. No Default. The Borrower is in full compliance with all
of the terms and conditions of this Agreement, and no Potential Default or Event
of Default is existing under this Agreement.

       Section 5.6.  ERISA.  The Borrower and its Subsidiaries are in
compliance in all material respects with ERISA to the extent applicable to it
and neither the Borrower nor any Subsidiary has received any notice to the
contrary from the PBGC or any other governmental entity or agency.  No steps
have been taken to terminate any Plan, and no contribution failure has occurred
with respect to any Plan sufficient to give rise to a lien under Section 302(f)
of ERISA.  No condition exists or event or transaction has occurred with respect
to any Plan which might result in the incurrence by the Borrower or any
Subsidiary of any material liability, fine or penalty.  Neither the Borrower nor
any Subsidiary has any contingent liability with respect to any post-retirement
benefit under a Plan, other than liability for continuation coverage described
in Part 6 of Title I of ERISA.

       Section 5.7.  Debt and Security Interests.  The Borrower and its
Subsidiaries have no Debt except Debt permitted by Section 7.10 hereof, and
there are no security interests, liens or encumbrances on any of the assets or
Property of the Borrower or any Subsidiary except for those permitted by Section
7.9 hereof.

       Section 5.8.  Subsidiaries.  The Borrower's only Subsidiaries as of
the date hereof are identified on Exhibit G hereof.  Each of said Subsidiaries
is duly organized and validly existing under the laws of the state or country of
its incorporation or formation, has full and adequate corporate power to carry
on its business as now conducted, and is duly licensed or qualified to do
business in all jurisdictions wherein the nature of its activities requires such
licensing or qualification, except where the failure to be so licensed or
qualified would not result in a material adverse change in the Properties,
business or operations of the Borrower and its Subsidiaries taken as a whole.

       Section 5.9.  Accurate Information.  No information, exhibit or report
furnished by the Borrower or any Subsidiary to the Banks in connection with the
negotiation or performance of the Loan Documents contains any material
misstatement of fact or omitted to state a material fact or any fact necessary
to make the statements contained therein not misleading in light of the
circumstances in which made.

       Section 5.10.  Enforceability.  This Agreement is and the other Loan
Documents to which the Borrower is a party are the legal, valid and binding
agreements of the Borrower, enforceable against it in accordance with its terms,
except as may be limited by (a) bankruptcy, insolvency, reorganization,
fraudulent transfer, moratorium or other similar laws or judicial decisions for
the relief of debtors or the limitation of creditors' rights generally; and (b)
any equitable principles relating to or limiting the rights of creditors
generally or any equitable remedy which may be granted to cure any defaults.

       Section 5.11.  Restrictive Agreements.  The Borrower is not a party to
any contract or agreement, or subject to any charge or other corporate
restriction, which affects its ability to execute, deliver and perform the Loan
Documents to which it is a party and repay its indebtedness, obligations and
liabilities under the Loan Documents or which materially and adversely affects
the financial condition or results of operations of the Borrower and its
Subsidiaries taken as a whole, or would materially and adversely affect the
Borrower's legal ability to repay the indebtedness, obligations and liabilities
under the Loan Documents, or any Bank's or the Agent's rights under the Loan
Documents to which the Borrower is a party.
<PAGE>
 
       Section 5.12.  No Violation of Law.  Neither the Borrower nor any
Subsidiary is in violation of any law, statute, regulation, ordinance, judgment,
order or decree applicable to it which violation would materially and adversely
affect any Bank's or any Agent's rights under the Loan Documents or the
financial condition or results of operations of the Borrower and its
Subsidiaries taken as a whole.

       Section 5.13. No Default Under Other Agreements. Neither the Borrower nor
any Subsidiary is in default with respect to any note, indenture, loan
agreement, mortgage, lease, deed, or other agreement to which it is a party or
by which it or its Property is bound, which default would materially and
adversely affect any Bank's or any Agent's rights under the Loan Documents or
the financial condition or results of operations of the Borrower and its
Subsidiaries taken as a whole.

       Section 5.14.  Status Under Certain Laws.  Neither the Borrower nor
any of its Subsidiaries is an "investment company" or a person directly or
indirectly controlled by or acting on behalf of an "investment company" within
the meaning of the Investment Company Act of 1940, as amended, or a "holding
Company," or a "subsidiary company" of a "holding company", or an "affiliate" of
a "holding company" or a "subsidiary company" of a "holding company," within the
meaning of the Public Utility Holding Company Act of 1935, as amended.

       Section 5.15.  Pari Passu.  All payment obligations of the Borrower
arising under or pursuant to this Agreement and the Notes will at all times rank
pari passu with the Borrower's indebtedness evidenced by the Senior Notes.

Section 6. Conditions Precedent.

       The obligation of the Banks or the Administrative Agent to make any Loan
pursuant hereto shall be subject to the following conditions precedent:

       Section 6.1.  Initial Extension of Credit.  Prior to the initial Loan
hereunder, the following conditions precedent shall have been satisfied:

       (a) the Borrower shall have delivered to the Administrative Agent for the
benefit of the Banks in sufficient counterparts for distribution to the Banks:

            (i)  the Notes (one for each Bank);
<PAGE>
 
            (ii) good standing certificates for the Borrower issued by the
     states of Louisiana, New Mexico and Mississippi, as applicable, issued not
     more than 30 days before the date of this Agreement;

            (iii)  copies of the Articles of Incorporation, and all amendments
     thereto, of the Borrower, certified by the Secretary of State of its state
     of incorporation not more than 30 days before the date of this Agreement;

            (iv) copies of the By-Laws, and all amendments thereto, of the
     Borrower, certified as true, correct and complete on the date hereof by the
     Secretary or Assistant Secretary of the Borrower;

            (v) copies, certified as true, correct and complete by the Secretary
     or Assistant Secretary of the Borrower, of resolutions regarding the
     transactions contemplated by this Agreement, duly adopted by the Board of
     Directors of the Borrower and satisfactory in form and substance to the
     Agents;

            (vi) a pay-off letter from the Existing Banks under each of the
     Existing Agreements;

            (vii)  an incumbency and signature certificate for the Borrower
     satisfactory in form and substance to the Agents; and

            (viii)  copies (executed or certified, as may be appropriate) of all
     legal documents or proceedings taken in connection with the execution and
     delivery of this Agreement and the other Loan Documents to the extent the
     Administrative Agent may reasonably request.

       (b) the Agents shall have received all fees payable to them in connection
with the execution and delivery of this Agreement and the transactions
contemplated hereby;

       (c) the Administrative Agent shall have received evidence of insurance
required by Section 7.3 hereof; and

       (d) the Administrative Agent shall have received copies, certified as
true, correct and complete by the secretary or assistant secretary of the
Borrower, of the indenture, prospectus and underwriting agreement relating to
the Borrower's Senior Notes.

       Section 6.2.  Each Extension of Credit.  As of the time of the
making of each Loan hereunder (including the initial Loan):

       (a) each of the representations and warranties set forth in Section 5
hereof shall be and remain true and correct as of said time, except that the
representations and warranties made under Section 5.2 shall be deemed to refer
to the most recent financial statements furnished to the Banks pursuant to
Section 7.4 hereof;
<PAGE>
 
       (b) the Borrower shall be in full compliance with all of the terms and
conditions hereof, and no Potential Default or Event of Default shall have
occurred and be continuing;

       (c) with respect to each Loan requested by the Borrower, the aggregate
amount of the Total Outstandings shall not exceed the Revolving Credit
Commitments;

       (d) immediately after giving effect thereto, not more than 25% of the
value of the Borrower's and its Subsidiaries' assets that are subject to
Sections 7.9 and 7.12 hereof shall constitute margin stock (as defined in
Regulation U promulgated by the Board of Governors of the Federal Reserve
System); and

       (e) with respect to each Swingline Loan requested by the Borrower, the
aggregate principal amount of all Swingline Loans outstanding after giving
effect to the requested Swingline Loans shall not exceed $25,000,000;

and the request by the Borrower, for any Loan pursuant hereto shall be and
constitute a warranty to the foregoing effects.

       Section 6.3. Legal Matters. Legal matters incident to the execution
and delivery of the Loan Documents shall be satisfactory to each of the Banks
and their legal counsel; and prior to the initial Loan hereunder, the
Administrative Agent shall have received the favorable written opinion of Hughes
& Luce, L.L.P., counsel for the Borrower, substantially in the form of Exhibit
I, in substance satisfactory to each of the Banks and their respective legal
counsel.

       Section 6.4. Documents. The Administrative Agent shall have received
copies (executed or certified, as may be appropriate) of all documents or
proceedings taken in connection with the execution and delivery of the Loan
Documents to the extent the Required Banks or their respective legal counsel
reasonably request.

Section 7. Covenants.

       It is understood and agreed that so long as credit is in use or available
under this Agreement or any amount remains unpaid on any Note, Reimbursement
Obligation or L/C except to the extent compliance in any case or cases is waived
in writing by the Required Banks:

       Section 7.1. Maintenance of Property. The Borrower will, and will
cause each Subsidiary to, keep and maintain all of its Properties necessary or
useful in its business in good condition, and make all necessary renewals,
replacements, additions, betterments and improvements thereto; provided,
however, that nothing in this Section shall prevent the Borrower or any
Subsidiary from discontinuing the operating and maintenance of any of its
properties if such discontinuance is, in the judgment of the Borrower, desirable
in the conduct of its business and not disadvantageous in any material respect
to the Banks as holders of the Notes.
<PAGE>
 
       Section 7.2. Taxes. The Borrower will, and will cause each
Subsidiary to, duly pay and discharge all taxes, rates, assessments, fees and
governmental charges upon or against the Borrower or any Subsidiary or against
its Properties in each case before the same becomes delinquent and before
penalties accrue thereon unless and to the extent that the same is being
contested in good faith and by appropriate proceedings and for which adequate
reserves have been established in accordance with generally accepted accounting
principles, consistently applied.

       Section 7.3. Maintenance of Insurance. The Borrower will, and will
cause each Subsidiary to, maintain insurance with insurers recognized as
financially sound and reputable by prudent business persons in such forms and
amounts and against such risks as is usually carried by companies engaged in
similar business and owning similar Properties in the same general areas in
which the Borrower or such Subsidiary operates.  The Borrower shall provide the
Administrative Agent with evidence of insurance maintained by it upon the
Administrative Agent's request.

       Section 7.4. Financial Reports. The Borrower will, and will cause
each Subsidiary to, maintain a system of accounting in accordance with sound
accounting practice and will furnish promptly to each of the Banks and their
duly authorized representatives such information respecting the business and
financial condition of the Borrower and its Subsidiaries as may be reasonably
requested and, without any request, will furnish each Bank:

       (a) as soon as available, and in any event within 45 days after the close
of the first three fiscal quarters of each fiscal year of the Borrower a copy of
consolidated and consolidating balance sheets and income statements and
consolidated cash flow statements for the Borrower and its Subsidiaries for such
quarterly period and the year to date and for the corresponding periods of the
preceding fiscal year, all in reasonable detail, prepared by the Borrower and
certified by the chief financial officer of the Borrower;

       (b) as soon as available, and in any event within 90 days after the close
of each fiscal year of the Borrower, a copy of the audit report for such year
and accompanying financial statements, including consolidated balance sheets and
statements of income for the Borrower and its Subsidiaries showing in
comparative form the figures for the previous fiscal year of the Borrower, all
in reasonable detail, prepared and certified by Arthur Andersen LLP or other
independent public accountants of nationally recognized standing selected by the
Borrower and reasonably satisfactory to the Administrative Agent and copies of
unaudited consolidating balance sheets and statements of income for the Borrower
and its Subsidiaries;

       (c) together with the financial statements required by (a) and (b) above,
a Compliance Certificate in the form of Exhibit H attached hereto, prepared and
signed by the President or Chief Financial Officer of the Borrower;

       (d) promptly upon their becoming available, copies of all registration
statements and regular periodic reports, if any, which the Borrower shall have
filed with the Securities and Exchange Commission or any governmental agency
substituted therefor, or any national securities exchange, including copies of
the Borrower's form 10-K annual report, including financial statements audited
by Arthur Andersen LLP or other independent public accountants of nationally
recognized standing selected by the Borrower and reasonably satisfactory to the
Required Banks, its form 10-Q quarterly report to the Securities and Exchange
Commission and any Form 8-K filed by the Borrower with the Securities and
Exchange Commission;
<PAGE>
 
       (e) promptly upon the mailing thereof to the shareholders of the Borrower
generally, copies of all financial statements, reports and proxy statements so
mailed; and

       (f) as soon as available, and in any event within 45 days after the close
of the last fiscal quarter of each fiscal year of the Borrower and its
Subsidiaries either (i) a Compliance Certificate in the form required by
subsection (c) above or (ii) a certificate in the form of Exhibit K attached
hereto (the "Pricing Ratio Certificate") prepared and signed by the President or
Chief Financial Officer of the Borrower showing the calculation of the Pricing
Ratio as of the last day of the fiscal quarter of the Borrower and its
Subsidiaries then ended.

       Section 7.5. Inspection. The Borrower shall, and shall cause each
Subsidiary to, permit each of the Banks, by their representatives and
Administrative Agents, to inspect any of the Properties, corporate books and
financial records of the Borrower, and each Subsidiary, to examine and make
copies of the books of accounts and other financial records of the Borrower and
its Subsidiaries and to discuss the affairs, finances and accounts of the
Borrower and its Subsidiaries with, and to be advised as to the same by, its
officers at such reasonable times and reasonable intervals as the Required Banks
may reasonably request.  The Borrower shall pay the reasonable costs and
expenses of the Administrative Agent in connection with any inspection of the
Borrower's and its Subsidiaries' books and records.

       Section 7.6. Consolidation and Merger. The Borrower will not, and
will not permit any Subsidiary to, consolidate with or merge into any Person, or
permit any other Person to merge into it, except that:

       (a) any Person may merge into the Borrower or any Subsidiary so long as:

           (i) the Borrower or Subsidiary shall be the surviving entity;
     provided, however, that the Borrower or Subsidiary is not required to be
     the surviving entity if the Borrower's or Subsidiary's board of directors
     becomes a majority of the board of directors of the surviving entity
     immediately upon completion of such transaction and such surviving Person
     shall agree to assume each and every obligation of the Borrower or
     Subsidiary pursuant to this Agreement and any other Loan Document;

           (ii) the Person merging with or into the Borrower or a Subsidiary of
     a Borrower shall be in the same line or a related line of business as the
     Borrower or a Subsidiary of the Borrower;
<PAGE>
 
            (iii)  the board of directors (or equivalent governing body) of such
     Person shall have given its prior effective written consent or approval of
     such merger; and

            (iv) no Potential Default or Event of Default shall exist before or
     after giving effect to such merger; and

       (b) any Subsidiary may be merged or consolidated with or into:  (i) the
Borrower, if the Borrower should be the continuing or surviving corporation, or
(ii) any other Subsidiary.

       Section 7.7.  Transactions with Affiliates.  The Borrower will not,
and will not permit any Subsidiary to, enter into any transaction, including
without limitation, the purchase, sale, lease or exchange of any Property, or
the rendering of any service, with any Affiliate of the Borrower except in the
ordinary course of, and pursuant to the reasonable requirements of, the
Borrower's or such Subsidiary's business and upon fair and reasonable terms no
less favorable to the Borrower or such Subsidiary than would be obtained in a
comparable arm's-length transaction with a Person not an Affiliate of the
Borrower, provided that the Borrower may continue to engage in the following
practices:  (i) allocation of overhead expenses among the Borrower and its
Subsidiaries, (ii) special product pricing among the Borrower and one or more
Subsidiaries and Mississippi Chemical Company, L.P., and (iii) the floor price
provision of the ammonia purchase agreements between the Borrower and Farmland
MissChem Limited.

       Section 7.8.  Dividends and Certain Other Restricted Payments.  The
Borrower will not (a) declare or pay any dividends or make any distribution on
any class of its capital stock (other than dividends payable solely in its
capital stock) or (b) directly or indirectly purchase, redeem or otherwise
acquire or retire any of its capital stock (except out of the proceeds of, or in
exchange for, a substantially concurrent issue and sale of capital stock) or (c)
make any other distributions with respect to its capital stock (collectively,
"Restricted Payments"); unless no Potential Default or Event of Default shall
exist before and after giving effect thereto.

       Section 7.9.  Liens.  The Borrower will not, and will not permit any
Subsidiary to, pledge, mortgage or otherwise encumber or subject to or permit to
exist upon or be subjected to any lien, charge or security interest of any kind
(including any conditional sale or other title retention agreement and any lease
in the nature thereof), on any of its Properties of any kind or character at any
time owned by the Borrower or any Subsidiary, other than:

       (a) liens, pledges or deposits for worker's compensation, unemployment
insurance, old age benefits or social security obligations, taxes, assessments,
statutory obligations or other similar charges, good faith deposits made in
connection with tenders, contracts or leases to which the Borrower or any
Subsidiary is a party or other deposits required to be made in the ordinary
course of business, provided in each case the obligation secured is not overdue
or, if overdue, is being contested in good faith by appropriate proceedings and
adequate reserves have been provided therefor in accordance with generally
accepted accounting principles and that the obligation is not for borrowed
money, customer advances, trade payables, or obligations to agricultural
producers;
<PAGE>
 
       (b) the pledge of assets for the purpose of securing an appeal or stay or
discharge in the course of any legal proceedings, provided that the aggregate
amount of liabilities of the Borrower or any Subsidiary so secured by a pledge
of property permitted under this subsection (b) including interest and penalties
thereon, if any, shall not be in excess of $10,000,000 at any one time
outstanding;

       (c) liens, pledges, mortgages, security interests or other charges
existing on the date hereof and disclosed in the audited financial statements
referred to in Section 5.2 hereof;

       (d) liens for property taxes and assessments or governmental charges or
levies which are not yet due and payable;

       (e) liens incidental to the conduct of business or the ownership of
properties and assets (including warehousemen's and attorneys' liens and
statutory landlords' liens) or other liens of like general nature incurred in
the ordinary course of business and not in connection with the borrowing of
money, provided in each case, the obligation secured is not overdue or, if
overdue, is being contested in good faith by appropriate actions or proceedings
and adequate reserves have been provided therefor in accordance with generally
accepted accounting principles, consistently applied;

       (f) minor survey exceptions or minor encumbrances, easements or
reservations, or rights of others for rights-of-way, utilities and other similar
purposes, or zoning or other restrictions as to the use of real properties,
which are necessary for the conduct of the activities of the Borrower and its
Subsidiaries or which customarily exist on properties of corporations engaged in
similar activities and similarly situated and which do not in any event
materially impair their use in the operation of the business of the Borrower and
its Subsidiaries;

       (g) the interests of lessors under Capitalized Leases;

       (h) liens (including the owner's interest in Property involved in Sale
and Leaseback transactions permitted by Section 7.17 of this Agreement to which
the Borrower or any Subsidiary is a party) not otherwise permitted under this
Section 7.9 on Property of the Borrower and its Subsidiaries securing Debt and
the indebtedness, obligations and liabilities of the Borrower and its
Subsidiaries under Sale and Leaseback transactions to which they are a party
that is in an aggregate outstanding principal amount not exceeding 15% of the
amount (determined in accordance with generally accepted accounting principles
consistently applied as shown on the most recent financial statements delivered
pursuant to Section 7.4 hereof) of the Borrower's Net Tangible Assets, provided
that the aggregate amount of all such indebtedness, obligations and liabilities
secured by liens and security interests on the Borrower's Subsidiaries' Property
shall not exceed $10,000,000 at any time;
<PAGE>
 
       (i) liens upon tangible personal property acquired after the date hereof
(by purchase, construction or otherwise), or upon other Property acquired after
the date hereof as a capital expenditure, by the Borrower or any of its
Subsidiaries, each of which liens either (A) existed on such Property before the
time of its acquisition and was not created in anticipation thereof or (B) was
created solely for the purpose of securing indebtedness representing, or
incurred to finance, refinance or refund, the cost of such Property; provided
that (I) no such lien shall extend to or cover any Property of the Borrower or
any of its Subsidiaries other than the Property so acquired, (II) the principal
amount of indebtedness secured by any such lien shall not exceed the fair market
value of such Property at the time of acquisition, and (C) the aggregate
principal amount of all indebtedness secured by such liens shall not at any one
time exceed $10,000,000; and

       (j) liens, mortgages and security interests securing the Borrower's and
its Subsidiaries' indebtedness, obligations and liabilities in connection with
industrial revenue bonds issued for their account which are permitted by Section
7.10(b), provided such liens, mortgages and security interests attach only to
the Property financed by such industrial revenue bonds.

       Section 7.10.  Borrowings and Guaranties.  The Borrower will not, and
will not permit any Subsidiary to, issue, incur, assume, create or have
outstanding any Debt, nor be or remain liable, whether as endorser, surety,
guarantor or otherwise, for or in respect of any Debt of any other Person, other
than:

       (a) indebtedness of the Borrower arising under or pursuant to this
Agreement or the other Loan Documents;

       (b) indebtedness of the Borrower or the Borrower's Subsidiaries relating
to industrial revenue bonds issued for their account, and any indebtedness
issued or incurred to refinance such indebtedness, provided that the aggregate
principal amount of all such indebtedness shall not exceed $14,500,000 at any
time;

       (c) the liability of the Borrower and its Subsidiaries arising out of the
endorsement for deposit or collection of commercial paper received in the
ordinary course of business;

       (d) indebtedness of the Borrower and its Subsidiaries existing on the
date hereof and disclosed to the Banks in the financial statements referred to
in Section 5.2 hereof, except indebtedness outstanding under the Existing
Agreements, and any indebtedness issued or incurred to refinance any of the
foregoing permitted indebtedness, provided that the principal amount of such
refinancing indebtedness does not exceed the principal amount of the
indebtedness being refinanced;

       (e) the liability of the Borrower with respect to the Farmland MissChem
Project Contingent Obligations disclosed on Exhibit J hereto;

       (f) indebtedness of the Borrower evidenced by the Senior Notes;
<PAGE>
 
       (g) indebtedness for borrowed money or Capitalized Lease Obligations of
the Borrower and its Subsidiaries not otherwise permitted by this Section 7.10;
provided that (i) the Borrower is in compliance with Section 7.20 hereof, and
(ii) the aggregate principal amount of all such indebtedness of the Borrower's
Subsidiaries permitted hereby shall not exceed $10,000,000 at any time;

       (h) the indebtedness of any Subsidiary to the Borrower or any other
Subsidiary; and

       (i) indebtedness of the Borrower to Deposit Guaranty National Bank in an
aggregate principal amount not to exceed $5,000,000 outstanding at any time.

       Section 7.11.  Investments, Loans, Advances and Acquisitions.  The
Borrower will not, and will not permit any Subsidiary to, make or retain any
investment (whether through the purchase of stock, obligations or otherwise) in
or make any loan or advance to, any other Person, or acquire substantially as an
entirety the Property or business of any other Person, other than:

       (a) investments in direct obligations of the United States of America or
of any agency or instrumentality thereof whose obligations constitute full faith
and credit obligations of the United States of America, provided that any such
obligations shall mature within one year of the date of issuance thereof;

       (b) investments in commercial paper rated either P-1 by Moody's Investors
Services, Inc. or A-1 by Standard & Poor's Corporation maturing within 270 days
of the date of issuance thereof;

       (c) investments in certificates of deposit issued by any United States
commercial bank or a branch located in the United States of a foreign commercial
bank in each case having capital and surplus of not less than $500,000,000 which
have a maturity of one year or less;

       (d) investments in repurchase obligations with a term of not more than
thirty (30) days for underlying securities of the types described in subsection
(a) above entered into with any bank meeting the qualifications specified in
subsection (c) above, provided all such agreements require physical delivery of
the securities securing such repurchase agreement, except those delivered
through the Federal Reserve Book Entry System;

       (e) investments in money market funds that invest solely, and which are
restricted by their respective charters to invest solely, in investments of the
type described in the immediately preceding subsections (a), (b), (c) and (d)
above;

       (f) marketable general obligations of a state, a territory or a
possession of the United States, or any political subdivision of any of the
foregoing, or the District of Columbia, unconditionally secured by the full
faith and credit of such state, territory, possession, political subdivision or
district provided that such state, territory, possession, political subdivision
or district has general taxing authority and the power to levy such taxes as may
be required for the payment of principal and interest thereof; provided that
such obligations are rated in either of the two top rating categories
established by the national rating agencies for such obligations;
<PAGE>
 
       (g) marketable corporate debt securities having an A credit rating or
better by Standard & Poor's Corporation or Moody's Investors Service;

       (h) investments shown on the financial statements referred to in Section
5.2;

       (i) investments by the Borrower or any Subsidiary in, and loans and
advances from the Borrower or any Subsidiary to, any Subsidiary;

       (j) other investments by the Borrower in and acquisitions (other than by
merger or consolidation) by the Borrower of the Property or business of any
Person or a majority of the capital stock or other equity interests of any other
Person, provided that:

            (i) such Person shall be in the same or a related line of business
     as the Borrower or one or more Subsidiaries;

            (ii) the board of directors (or equivalent governing body) of such
     Person shall have given its prior effective written consent or approval of
     such acquisition; and

            (iii)  no Potential Default or Event of Default shall exist before
     or after giving effect to such acquisition;

       (k) investments in or loans to Farmland MissChem Ltd. in connection with
the Farmland MissChem Project in an aggregate amount not exceeding $100,000,000
at any one time outstanding;

       (l) investments, loans and advances by the Borrower not otherwise
permitted under this Section 7.11 in an aggregate amount not exceeding 10% of
the Tangible Net Worth of the Borrower at any one time outstanding; and

       (m) loans and advances to employees in the ordinary course of business,
provided the aggregate principal amount of all such loans and advances made by
the Borrower's Subsidiaries shall not exceed $500,000 at any time.

       Section 7.12.  Sale of Property.  The Borrower will not and will not
permit any Subsidiary to, sell, lease, assign, transfer or otherwise dispose of
(whether in one transaction or in a series of related transactions) all or a
material part of its Property to any other Person during each fiscal year of the
Borrower; provided, however, that the Borrower and its Subsidiaries may make:

       (a) sales of its Inventory in the ordinary course of business,
<PAGE>
 
       (b) sales or leases of its machinery and equipment that is obsolete,
unusable or not needed for the Borrower's or such Subsidiary's operations in the
ordinary course of its business,

       (c) Sale and Leaseback transactions permitted by Section 7.17 hereof; and

       (d) during each fiscal year, sales of Property having a fair market value
up to 10% of the Total Assets of the Borrower; provided, however, sales of
Property having a fair market value greater than 10% and up to 15% of the Total
Assets of the Borrower shall be permitted, so long as the amount of the net
proceeds of such sale in excess of 10% of the Total Assets of the Borrower are
applied to the payment of Debt or reinvested in a line of business of the
Borrower or one or more of its Subsidiaries.

       For purposes of this Section, "material part" shall mean Property having
a fair market value in excess of an amount equal to 5% of the Total Assets of
the Borrower.

       Section 7.13. Notice of Suit or Adverse Change in Business or Default.
The Borrower shall, as soon as possible, and in any event within five (5) days
after the Borrower learns of the following, give written notice to the Banks of
(a) any material proceeding(s) being instituted or threatened to be instituted
by or against the Borrower or any Subsidiary in any federal, state, local or
foreign court or before any commission or other regulatory body (federal, state,
local or foreign), (b) any material adverse change in the business, Property or
condition, financial or otherwise of the Borrower and (c) the occurrence of any
Potential Default or Event of Default.

       Section 7.14. ERISA. The Borrower will, and will cause each Subsidiary
to, promptly pay and discharge all obligations and liabilities arising under
ERISA of a character which if unpaid or unperformed is likely to result in the
imposition of a lien against any of its Property and will promptly notify the
Administrative Agent of (a) the occurrence of any reportable event (as defined
in ERISA) which might result in the termination by the PBGC of any Plan, (b)
receipt of any notice from PBGC of its intention to seek termination of any such
Plan or appointment of a trustee therefor, and (c) its intention to terminate or
withdraw from any Plan. The Borrower will not, and will not permit any
Subsidiary to, terminate any such Plan or withdraw therefrom unless it shall be
in compliance with all of the terms and conditions of this Agreement after
giving effect to any liability to PBGC resulting from such termination or
withdrawal.

       Section 7.15. Use of Proceeds. The Borrower shall use the proceeds
of the initial Revolving Credit Loans to pay all or part of the indebtedness,
obligations and liabilities of the Borrower and the other obligors under the
Credit Agreement dated as of December 23, 1996 by and among the Borrower,
Mississippi Phosphates Corporation, Mississippi Potash, Inc., Harris Trust and
Savings Bank, as Administrative Agent and the banks named therein, and that
certain agreement dated as of December 23, 1996, by and among Triad Nitrogen,
Inc. (formerly known as First Mississippi Corporation), Harris Trust and Savings
Bank, as administrative Agent, and the lenders named therein (collectively, the
"Existing Agreements"), and of all other Loans made hereunder and of all L/C's
issued hereby for general corporate purposes, including, without limitation,
financing acquisitions, capital expenditures, refinancing existing debt and
providing for ongoing working capital needs.
<PAGE>
 
       Section 7.16.  Compliance with Laws, etc.  The Borrower will, and will
cause each of its Subsidiaries to, comply in all material respects with all
applicable laws, rules, regulations and orders, including Environmental Laws,
such compliance to include (without limitation) the maintenance and preservation
of its corporate or partnership existence and qualification as a foreign
corporation or partnership.

       Section 7.17.  Sale and Leaseback Transactions.  Neither the Borrower
nor any of its Subsidiaries shall, directly or indirectly, enter into any
arrangement with any Person providing for the Borrower or a Subsidiary to lease
or rent Property that the Borrower or a Subsidiary has or will sell or otherwise
transfer to such Person (a "Sale and Leaseback"), unless the aggregate net cash
proceeds of any such sales in any 12-month period are less than 10% of the fair
market value of the Borrower's Total Assets; provided, that (a) the Borrower may
enter into Sale and Leaseback transactions in which the aggregate net cash
proceeds of such sales, together with the net cash proceeds of all sales
permitted by Section 7.12(d) of this Agreement, in any 12-month period exceeds
10% but not 15% of the fair market value of the Borrower's Total Assets so long
as the amount of the net proceeds of such sales in excess of 10% of the
Borrower's Total Assets are reinvested in a line of business of the Borrower or
any of its Subsidiaries, and (b) no Subsidiary may be a party to any Sale and
Leaseback transaction entered into after the date of this Agreement if the net
cash proceeds of such sales, together with the net cash proceeds of all sales of
such Subsidiaries' Property permitted by Section 7.12(d) of this Agreement,
would exceed $10,000,000.

       Section 7.18.  Fiscal Quarters.  The Borrower shall not change its
fiscal quarters.

       Section 7.19.  New Subsidiaries.  Neither the Borrower nor any
Subsidiary shall, directly or indirectly, organize or acquire any Subsidiary not
listed on Exhibit G attached hereto, except as permitted by Section 7.11(j)
hereof.

       Section 7.20.  Maximum Leverage Ratio.  The Borrower will, as of the
last day of each fiscal quarter of the Borrower maintain a Leverage Ratio less
than or equal to 4.00 to 1.0.

       Section 7.21.  Minimum Interest Coverage Ratio.  The Borrower will, as
of the last day of each fiscal quarter of the Borrower, maintain an Interest
Coverage Ratio of not less than 2.50 to 1.0.

       Section 7.22.  Minimum Tangible Net Worth. The Borrower will, as of
the last day of each fiscal quarter of the Borrower specified below, maintain
its Tangible Net Worth in an amount not less than:

            (a) for the fiscal quarter ending September 30, 1997, $188,112,500;
     and
<PAGE>
 
            (b) for each fiscal quarter ending thereafter, the sum of (i) the
     minimum amount of Tangible Net Worth the Borrower was required to maintain
     during the immediately preceding fiscal quarter, plus (ii) 50% of the
     Borrower's Net Income (but not less than zero) for such fiscal quarter then
     ended.

     Section 7.23.  Operating Leases.  The Borrower will not, and will not
permit any Subsidiary to, enter into any rental agreement or lease as lessee of
real or personal property, which is not a Capitalized Lease if the aggregate of
Rentals payable in any fiscal year under all such rental agreements or leases
would exceed the greater of 4% of the Borrower's Total Assets at the beginning
of such fiscal year or $25,000,000.

     Section 7.24. No Restrictions on Subsidiaries. The Borrower shall not and
shall not permit any of its Subsidiaries directly or indirectly to create or
otherwise cause or suffer to exist or become effective any consensual
encumbrance or restriction of any kind on the ability of any Subsidiary (or the
Borrower, in the case of subsection (e) of this Section) to: (a) pay dividends
or make any other distribution on any of such Subsidiary's capital stock or
other equity interests owned by the Borrower or any Subsidiary of the Borrower;
(b) pay any indebtedness owed to the Borrower or any other Subsidiary; (c) make
loans or advances to the Borrower or any other Subsidiary; (d) transfer any of
its Property or assets to the Borrower or any other Subsidiary; or (e) merge or
consolidate with or into the Borrower or any other Subsidiary of the Borrower;
provided that (i) the foregoing shall not apply to restrictions and conditions
imposed by law or by this Agreement, (ii) the foregoing shall not apply to
restrictions and conditions existing on the date hereof identified on Schedule
7.24 (but shall apply to any extension or renewal of, or any amendment or
modification expanding the scope of, any such restriction or condition), (iii)
the foregoing shall not apply to customary restrictions and conditions contained
in agreements relating to the sale of a Subsidiary pending such sale, provided
such restrictions and conditions apply only to the Subsidiary that is to be sold
and such sale is permitted hereunder, and (iv) clause (d) of the foregoing shall
not apply to customary provisions in leases and other contracts restricting the
assignment thereof.

Section 8. Events of Default and Remedies.

       Section 8.1.  Definitions.  Any one or more of the following shall
constitute an Event of Default:

       (a) Default in the payment when due of (i) any principal of any Note or
any Reimbursement Obligation (ii) any interest on any Note or any Reimbursement
Obligation which continues unremedied for 5 Business Days, whether at the stated
maturity thereof or at any other time provided in this Agreement, or default in
the payment when due of any fee or other amount payable by the Borrower pursuant
to this Agreement, which continues unremedied for 5 Business Days;

       (b) Default in the observance or performance of any covenant set forth in
Sections 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 7.10, 7.11, 7.12, 7.13, 7.15, 7.16,
7.18, 7.19, 7.20, 7.21, 7.22, 7.23 or 7.24 hereof;
<PAGE>
 
       (c) Default in the observance or performance of any other covenant,
condition, agreement or provision hereof or any of the other Loan Documents and
such default shall continue for 30 days after written notice thereof to the
Borrower by any Bank;

       (d) Default shall occur under any evidence of Debt in a principal amount
exceeding $10,000,000 issued or assumed or guaranteed by the Borrower or any
Subsidiary, or under any mortgage, agreement or other similar instrument under
which the same may be issued or secured and such default shall continue for a
period of time sufficient to permit the acceleration of maturity of any
indebtedness evidenced thereby or outstanding or secured thereunder;

       (e) Any representation or warranty made by the Borrower herein or in any
Loan Document or in any statement or certificate furnished by it pursuant hereto
or thereto, proves untrue in any material respect as of the date made or deemed
made pursuant to the terms hereof;

       (f) Any judgment or judgments, writ or writs, or warrant or warrants of
attachment, or any similar process or processes in an aggregate amount in excess
of $10,000,000 shall be entered or filed against the Borrower or any Subsidiary
or against any of their respective Property or assets and remain unstayed and
undischarged for a period of 30 days from the date of its entry;

       (g) Any reportable event (as defined in ERISA) which constitutes grounds
for the termination of any Plan or for the appointment by the appropriate United
States District Court of a trustee to administer or liquidate any such Plan,
shall have occurred and be continuing thirty (30) days after written notice to
such effect shall have been given to the Borrower by any Bank; or any such Plan
shall be terminated; or a trustee shall be appointed by the appropriate United
States District Court to administer any such Plan; or the Pension Benefit
Guaranty Corporation shall institute proceedings to administer or terminate any
such Plan;

       (h) The Borrower or any Subsidiary shall (i) have entered involuntarily
against it an order for relief under the Bankruptcy Code of 1978, as amended,
(ii) admit in writing its inability to pay, or not pay, its debts generally as
they become due, (iii) make an assignment for the benefit of creditors, (iv)
apply for, seek, consent to, or acquiesce in, the appointment of a receiver,
custodian, trustee, conservator, liquidator or similar official for it or any
substantial part of its property, (v) file a petition seeking relief or
institute any proceeding seeking to have entered against it an order for relief
under the Bankruptcy Code of 1978, as amended, to adjudicate it insolvent, or
seeking dissolution, winding up, liquidation, reorganization, arrangement,
marshaling of assets, adjustment or composition of it or its debts under any law
relating to bankruptcy, insolvency or reorganization or relief of debtors or
fail to file an answer or other pleading denying the material allegations of any
such proceeding filed against it, or (vi) fail to contest in good faith any
appointment or proceeding described in Section 8.1(i) hereof;
<PAGE>
 
       (i) A custodian, receiver, trustee, conservator, liquidator or similar
official shall be appointed for the Borrower or any Subsidiary of the Borrower
or any substantial part of its respective Property, or a proceeding described in
Section 8.1(i)(v) shall be instituted against the Borrower or any Subsidiary of
the Borrower and such appointment continues undischarged or any such proceeding
continues undismissed or unstayed for a period of 90 days; or

       (j)  a Change of Control shall occur.

       Section 8.2.  Remedies for Non-Bankruptcy Defaults.  When any Event of
Default, other than an Event of Default described in subsections (h) and (i) of
Section 8.1 hereof, has occurred and is continuing, the Administrative Agent, if
directed by the Required Banks, shall give written notice to the Borrower and
take any or all of the following actions: (a) terminate the remaining Revolving
Credit Commitments hereunder on the date (which may be the date thereof) stated
in such notice, (b) declare the principal of and the accrued interest on the
Notes and Reimbursement Obligations to be forthwith due and payable and
thereupon the Notes and Reimbursement Obligations including both principal and
interest, shall be and become immediately due and payable without further
demand, presentment, protest or notice of any kind, and (c) take any action or
exercise any remedy under any of the Loan Documents or exercise any other
action, right, power or remedy permitted by law.  Any Bank may exercise the
right of set off with regard to any deposit accounts or other accounts or
investments maintained by the Borrower with any of the Banks.

       Section 8.3.  Remedies for Bankruptcy Defaults.  When any Event of
Default described in subsections (h) or (i) of Section 8.1 hereof has occurred
and is continuing, then the Notes and Reimbursement Obligations shall
immediately become due and payable without presentment, demand, protest or
notice of any kind, and the obligation of the Banks to extend further credit
pursuant to any of the terms hereof shall immediately terminate.

       Section 8.4.  L/Cs.  Promptly following the acceleration of the
maturity of the Notes pursuant to Section 8.2 or 8.3 hereof, the Borrower shall
immediately pay to the Administrative Agent for the benefit of the Banks the
full aggregate amount of all outstanding L/Cs issued for the Borrower's account
hereunder.  The Administrative Agent shall hold all such funds and proceeds
thereof as additional collateral security for the obligations of the Borrower to
the Banks under the Loan Documents.  The amount paid under any of the L/Cs for
which the Borrower has not reimbursed the Banks shall bear interest from the
date of such payment at the default rate of interest specified in Section
1.3(d)(i) hereof.

Section 9. Change in Circumstances Regarding Fixed Rate Loans.

       Section 9.1.  Change of Law.  Notwithstanding any other provisions of
this Agreement or any Note to the contrary, if at any time after the date hereof
with respect to Fixed Rate Loans, any Bank shall determine in good faith that
any change in applicable law or regulation or in the interpretation thereof
makes it unlawful for such Bank to make or continue to maintain any Fixed Rate
Loan or to give 
<PAGE>
 
effect to its obligations as contemplated hereby, such Bank shall promptly give
notice thereof to the Borrower describing in reasonable detail the basis for
such Bank's determination and to the Administrative Agent to such effect, and
such Bank's obligation to make, relend, continue or convert any such affected
Fixed Rate Loans under this Agreement shall terminate until it is no longer
unlawful for such Bank to make or maintain such affected Loan. The Borrower
shall prepay the outstanding principal amount of any such affected Fixed Rate
Loan made to it, together with all interest accrued thereon and all other
amounts due and payable to the Banks under Section 9.4 of this Agreement, on the
earlier of the last day of the Interest Period applicable thereto and the first
day on which it is illegal for such Bank to have such Loans outstanding;
provided, however, the Borrower may borrow a principal amount equal to the
principal amount of such affected Loan by means of another type of Loan
available hereunder, subject to all of the terms and conditions of this
Agreement.

       Section 9.2.  Unavailability of Deposits or Inability to Ascertain the
Adjusted Eurodollar Rate.  Notwithstanding any other provision of this Agreement
or any Note to the contrary, if prior to the commencement of any Interest Period
any Bank shall determine (i) that deposits in the amount of any Eurodollar Loan
scheduled to be outstanding are not available to it in the relevant market by
reason of circumstances affecting the interbank Eurodollar market generally or
(ii) by reason of circumstances affecting the relevant market, adequate and
reasonable means do not exist for ascertaining the Adjusted Eurodollar Rate,
then such Bank shall promptly give telephonic or telex notice thereof to the
Borrower, the Administrative Agent and the other Banks (such notice to be
confirmed in writing), and the obligation of the Banks to make, continue or
convert any such Fixed Rate Loan in such amount and for such Interest Period
shall terminate until deposits in such amount and for the Interest Period
selected by the Borrower shall again be readily available in the relevant market
and adequate and reasonable means exist for ascertaining the Adjusted Eurodollar
Rate.  Upon the giving of such notice, the Borrower may elect to either (i) pay
or prepay, as the case may be, such affected Loan or (ii) reborrow such affected
Loan as another type of Loan available hereunder, subject to all terms and
conditions of this Agreement.

       Section 9.3.  Taxes and Increased Costs.  With respect to the Fixed
Rate Loans, if any Bank shall determine in good faith that any change in any
applicable law, treaty, regulation or guideline (including, without limitation,
Regulation D of the Board of Governors of the Federal Reserve System) or any new
law, treaty, regulation or guideline, or any interpretation of any of the
foregoing by any governmental authority charged with the administration thereof
or any central bank or other fiscal, monetary or other authority having
jurisdiction over such Bank or its lending branch or the Fixed Rate Loans
contemplated by this Agreement (whether or not having the force of law) ("Change
in Law") shall:

            (i) impose, modify or deem applicable any reserve, special deposit
     or similar requirements against assets held by, or deposits in or for the
     account of, or Loans by, or any other acquisition of funds or disbursements
     by, such Bank (other than reserves included in the determination of the
     Adjusted Eurodollar Rate);
<PAGE>
 
            (ii) subject such Bank, any Fixed Rate Loan or any Note to any tax
     (including, without limitation, any United States interest equalization tax
     or similar tax however named applicable to the acquisition or holding of
     debt obligations and any interest or penalties with respect thereto), duty,
     charge, stamp tax, fee, deduction or withholding in respect of this
     Agreement, any Fixed Rate Loan or any Note except such taxes as may be
     measured by the overall net income of such Bank or its lending branch and
     imposed by the jurisdiction, or any political subdivision or taxing
     authority thereof, in which such Bank's principal executive office or its
     lending branch is located;

            (iii)  change the basis of taxation of payments of principal and
     interest due from the Borrower to such Bank hereunder or under any Note
     (other than by a change in taxation of the overall net income of such
     Bank); or

            (iv) impose on such Bank any penalty with respect to the foregoing
     or any other condition regarding this Agreement, any Fixed Rate Loan or any
     Note;

and such Bank shall determine that the result of any of the foregoing is to
increase the cost (whether by incurring a cost or adding to a cost) to such Bank
of making or maintaining any Fixed Rate Loan hereunder or to reduce the amount
of principal or interest received by such Bank, then, if such Bank is generally
imposing payments for increased costs on its similarly situated customers, the
Borrower shall pay to such Bank from time to time as specified by such Bank such
additional amounts as such Bank shall reasonably determine are sufficient to
compensate and indemnify it for such increased cost or reduced amount.  If any
Bank makes such a claim for compensation, it shall provide to the Borrower a
certificate setting forth such increased cost or reduced amount as a result of
any event mentioned herein specifying such Change in Law, and such certificate
shall be conclusive and binding on the Borrower as to the amount thereof except
in the case of manifest error.  Upon the imposition of any such cost, the
Borrower may prepay any affected Loan, subject to the provisions of Sections 3.4
and 9.4 hereof.

       Section 9.4. Funding Indemnity. (a) In the event any Bank shall incur any
loss, cost, expense or premium (including, without limitation, any loss, cost,
expense or premium incurred by reason of the liquidation or re-employment of
deposits or other funds acquired by such Bank to fund or maintain any Fixed Rate
Loan or the relending or reinvesting of such deposits or amounts paid or prepaid
to such Bank) as a result of:

            (i) any payment or prepayment of a Fixed Rate Loan on a date other
     than the last day of the then applicable Interest Period;

            (ii) any failure by the Borrower to borrow, continue or convert any
     Fixed Rate Loan on the date specified in the notice given pursuant to
     Sections 1.7 or 2.4 hereof; or

            (iii)  the occurrence of any Event of Default;
<PAGE>
 
then, upon the demand of such Bank, the Borrower shall pay to such Bank such
amount as will reimburse such Bank for such actual loss, cost or expense (the
calculation of such loss or expense shall include a credit (not in excess of
such loss or expense) for the interest to be earned by such Bank as a result of
redepositing such amount in the relevant interbank market).

       (b) If any Bank makes a claim for compensation under this Section 9.4, it
shall provide to the Borrower a certificate setting forth the amount of such
loss, cost or expense in reasonable detail and such certificate shall be
conclusive and binding on the Borrower as to the amount thereof except in the
case of manifest error.

       Section 9.5.  Lending Branch.  Each Bank may, at its option, elect to
make, fund or maintain its Eurodollar Loans hereunder at the branch or office
specified opposite its signature on the signature page hereof or such other of
its branches or offices as such Bank may from time to time elect, subject to the
provisions of Section 1.7(b) hereof.

       Section 9.6.  Discretion of Bank as to Manner of Funding.
Notwithstanding any provision of this Agreement to the contrary, each Bank shall
be entitled to fund and maintain its funding of all or any part of its Loans in
any manner it sees fit, it being understood however, that for the purposes of
this Agreement all determinations hereunder shall be made as if the Banks had
actually funded and maintained each Fixed Rate Loan during each Interest Period
for such Loan through the purchase of deposits in the relevant interbank market
having a maturity corresponding to such Interest Period and bearing an interest
rate equal to the interest rate applicable thereto (exclusive of the Applicable
Margin) for such Interest Period.

       Section 9.7.  Mitigation of Circumstances; Replacement of Affected
Banks.

       (a) Banks' Duty to Mitigate.  Each Bank agrees that, as promptly as
practicable after it becomes aware of the occurrence of an event or the
existence of a condition that would cause it to be affected under Section 1.9,
9.1, 9.2 or 9.3 hereof, such Bank will, after written notice to the Borrower, to
the extent not inconsistent with such Bank's internal policies and customary
business practices, use its best efforts to make, fund or maintain the affected
Fixed Rate Loan or issue or participate in the affected L/C, as the case may be,
through another lending office of such Bank if as a result thereof the
unlawfulness which would otherwise require payment of such Fixed Rate Loan
pursuant to Section 9.1 or 9.2 hereof would cease to exist or the circumstances
which would otherwise terminate such Bank's obligation to make such Fixed Rate
Loan under Section 9.1 or 9.2 hereof would cease to exist or the increased costs
which would otherwise be required to be paid in respect of such Fixed Rate Loan
or L/C pursuant to Section 1.9 or 9.3 hereof would be materially reduced, and
if, as determined by such Bank, in its sole discretion, the making, funding or
maintaining of such Fixed Rate Loan, or issuance or participation in such L/C,
as the case may be, through such other lending office would not, in the judgment
of such Bank, be otherwise disadvantageous to such Bank.  The Borrower hereby
agrees to pay all reasonable expenses incurred by each such Bank in utilizing
another lending office pursuant to this Section 9.7(a).
<PAGE>
 
     (b) Replacement of Affected Banks.  At any time any Bank is affected by any
condition or circumstance set forth in Section 1.9, 9.1, 9.2 or 9.3, and so long
as no Event of Default, or Potential Default exists, (i) the Borrower may
replace such affected Bank as a party to this Agreement with one or more other
banks or financial institutions reasonably acceptable to the Administrative
Agent, (and upon notice from the Borrower such affected Bank shall assign,
pursuant to Section 11.17, without recourse or warranty, its Commitment, its
Loans, its Notes and all of its other rights and obligations hereunder to such
replacement banks or other financial institutions for a purchase price equal to
the sum of the principal amount of the Loans so assigned, all accrued and unpaid
interest thereon, its ratable share of all accrued and unpaid facility fees and
its ratable share of the remaining unpaid Reimbursement Obligations owed to the
affected Bank and all other amounts owed to such Bank under the Loan Documents)
and/or (ii) the Borrower may (and, if the Borrower replaces any affected Bank in
part as provided in clause (i) above, concurrently with such replacement the
Borrower shall) cause such affected Bank to cease to be a party hereto by
terminating the Commitment of such Bank, paying the principal amount of such
affected Bank's Loans, all accrued and unpaid interest thereon, all accrued and
unpaid facility fees owed to such affected Bank and the remaining unpaid
Reimbursement Obligations owed to such affected Bank and any other amounts due
to such affected Bank under the Loan Documents, in each case to the extent not
assigned and purchased pursuant to clause (i) above, and such affected Bank
shall thereupon cease to be a party hereto.

Section 10. The Agents.

     Section 10.1.  Appointment and Powers.  (a) Harris is hereby appointed
by the Banks as Administrative Agent under the Loan Documents and each of the
Banks hereby irrevocably authorizes the Administrative Agent to act as the
Administrative Agent of such Bank.  The Administrative Agent agrees to act as
such upon the express conditions contained in the Loan Documents.

     (b) Bank of Montreal is hereby appointed by the Administrative Agent as
Syndication Agent under the Loan Documents and the Administrative Agent hereby
irrevocably authorizes the Syndication Agent to act as the Syndication Agent for
the Banks.  The Syndication Agent agrees to act as such upon the express
conditions contained in the Loan Documents.

     Section 10.2.  Powers.  The Agents shall have and may exercise such
powers hereunder as are specifically delegated to the Agents by the terms of the
Loan Documents, together with such powers as are incidental thereto.  The Agents
shall have no implied duties to the Banks nor any obligation to the Banks to
take any action under the Loan Documents except any action specifically provided
by the Loan Documents to be taken by the Agents.

     Section 10.3.  General Immunity.  Neither any Agent nor any of such
Agent's directors, officers, agents or employees shall be liable to the Banks or
any Bank for any action taken or omitted to be taken by it or them under the
Loan Documents or in connection therewith except for its or their own gross
negligence or willful misconduct.
<PAGE>
 
     Section 10.4.  No Responsibility for Loans, Recitals, etc.  No Agent
shall (i) be responsible to the Banks for any recitals, reports, statements,
warranties or representations contained in the Loan Documents or furnished
pursuant thereto, (ii) be responsible for any Loans by any other Bank hereunder,
or (iii) be bound to ascertain or inquire as to the performance or observance of
any of the terms of the Loan Documents.  In addition, no Agent nor such Agent's
counsel shall be responsible to the Banks for the enforceability or validity of
any of the Loan Documents.

     Section 10.5.  Right to Indemnity.  The Banks hereby indemnify each
Agent for any actions taken in accordance with this Section 10, and each Agent
shall be fully justified in failing or refusing to take any action hereunder
unless it shall first be indemnified to its satisfaction by the Banks pro rata
against any and all liability and expense which may be incurred by it by reason
of taking or continuing to take any such action, other than any liability which
may arise out of such Agent's gross negligence or willful misconduct.

     Section 10.6.  Action Upon Instructions of Banks.  Each Agent agrees,
upon the written request of the Required Banks, to take any action of the type
specified in the Loan Documents as being within such Agent's rights, duties,
powers or discretion.  Each Agent shall in all cases be fully protected in
acting, or in refraining from acting, hereunder in accordance with written
instructions signed by the Required Banks (or all of the Banks, as applicable),
and such instructions and any action taken or failure to act pursuant thereto
shall be binding on all of the Banks and on all holders of the Notes.  In the
absence of a request by the Required Banks, each Agent shall have authority, in
its sole discretion, to take or not to take any action, unless the Loan
Documents specifically require the consent of the Required Banks or all of the
Banks.

     Section 10.7.  Employment of Agents and Counsel.  Each Agent may
execute any of its duties as Agent hereunder by or through employees, agents,
and attorneys-in-fact and shall not be answerable to the Banks, except as to
money or securities received by it or its authorized agents, for the default or
misconduct of any such agents or attorneys-in-fact selected by it in good faith
and with reasonable care.  Each Agent shall be entitled to advice and opinion of
legal counsel concerning all matters pertaining to the duties of the agencies
hereby created.

     Section 10.8. Reliance on Documents; Counsel.  Each Agent shall be
entitled to rely upon any note, notice, consent, certificate, affidavit, letter,
telegram, statement, paper or document believed by it to be genuine and correct
and to have been signed or sent by the proper person or persons, and, in respect
to legal matters, upon the opinion of legal counsel selected by such Agent.

       Section 10.9.  May Treat Payee as Owner.  Each Agent may deem and
treat the payee of any Note as the owner thereof for all purposes hereof unless
and until a written notice of the assignment or transfer thereof shall have been
filed with such agent.  Any request, authority or consent of any person, firm or
corporation who at the time of making such request or giving such authority or
consent is the holder of any such Note shall be conclusive and binding on any
subsequent holder, transferee or assignee of such Note or of any Note issued in
exchange therefor.
<PAGE>
 
          Section 10.10.  Agents' Reimbursement.  Each Bank agrees to reimburse
each Agent pro rata in accordance with its Commitment Percentage for any
reasonable out-of-pocket expenses (including fees and charges for inspections)
not reimbursed by the Borrower (a) for which such Agent is entitled to
reimbursement by the Borrower under the Loan Documents and (b) for any other
reasonable expenses incurred by such Agent on behalf of the Banks, in connection
with the preparation, execution, delivery, administration and enforcement of the
Loan Documents.

          Section 10.11.  Rights as a Bank.  With respect to its commitment,
Loans made by it, L/Cs issued by it, and the Notes issued to it, each Agent
shall have the same rights and powers hereunder as any Bank and may exercise the
same as though it were not such Agent, and the term "Bank" or "Banks" shall,
unless the context otherwise indicates, include each Agent in its individual
capacity to the extent, if any, of its Revolving Credit Commitment.  Each Agent
may accept deposits from, lend money to, and generally engage in any kind of
banking or trust business with the Borrower as if it were not such Agent.

          Section 10.12.  Bank Credit Decision.  Each Bank acknowledges that it
has, independently and without reliance upon any Agent or any other Bank and
based on the financial statements referred to in Section 5.2 and such other
documents and information as it has deemed appropriate, made its own credit
analysis and decision to enter into the Loan Documents.  Each Bank also
acknowledges that it will, independently and without reliance upon any Agent or
any other Bank and based on such documents and information as it shall deem
appropriate at the time, continue to make its own credit decisions in taking or
not taking action under the Loan Documents.

          Section 10.13.  Resignation of Agent.  Subject to the appointment of a
successor Agent, each Agent may resign as Agent for the Banks under this
Agreement and the other Loan Documents at any time by thirty days' notice in
writing to the Banks.  Such resignation shall take effect upon appointment of
such successor.  The Required Banks shall have the right to appoint a successor
Agent, subject to the prior consent of the Borrower (which consent shall not be
unreasonably withheld or delayed), who shall be entitled to all of the rights
of, and vested with the same powers as, the original Agent under the Loan
Documents.  In the event a successor Agent shall not have been appointed within
the sixty day period following the giving of notice by any Agent, such Agent may
appoint its own successor.  Resignation by any Agent shall not affect or impair
the rights of such Agent under Sections 10.5 and 10.10 hereof with respect to
all matters preceding such resignation.  Any successor Agent must be either a
Bank or a national banking association or a bank chartered in any State of the
United States, in each case having capital and surplus of not less than
$500,000,000.

          Section 10.14.  Duration of Agency.  The agency established by Section
10.1 hereof shall continue, and Sections 10.1 through and including this Section
10.14 shall remain in full force and effect, until the Notes and all other
amounts due hereunder and thereunder shall have been paid in full and the Banks'
commitments to extend credit to or for the benefit of the Borrower shall have
terminated or expired.
<PAGE>
 
          Section 10.15.  Syndication  Agent and Co-Agent.  Nothing in this
Agreement shall impose any obligation on Bank of Montreal in its capacity as
Syndication Agent or on Credit Agricole Indosuez as Co-Agent.

Section 11. Miscellaneous.

          Section 11.1.  Amendments and Waivers.  Any term, covenant, agreement
or condition of this Agreement and the other Loan Documents may be amended only
by a written amendment executed by the Borrower, the Required Banks and, if the
rights or duties of the Administrative Agent are materially affected thereby,
the Administrative Agent, or compliance therewith only may be waived (either
generally or in a particular instance and either retroactively or
prospectively), if the Borrower shall have obtained the consent in writing of
the Required Banks and, if the rights or duties of the Administrative Agent are
materially affected thereby, the Administrative Agent, provided, however, that
without the consent in writing of the holders of all outstanding Notes and
unpaid Reimbursement Obligations, or all Banks if no Notes or Obligations are
outstanding, no such amendment or waiver shall (a) change the amount or postpone
the date  of payment of any scheduled payment or required prepayment of
principal of the Notes or Reimbursement Obligations or extend the term of any
L/C at a time that the Borrower would not be able to obtain a Loan or L/C
hereunder or reduce the rate or extend the time of payment of interest on the
Notes or Reimbursement Obligations, or reduce the amount of principal thereof,
or modify any of the provisions of the Notes with respect to the payment or
prepayment thereof, (b) give to any Note or Reimbursement Obligations any
preference over any other Notes or Reimbursement Obligations, (c) amend the
definition of Required Banks, (d) alter, modify or amend the provisions of this
Section 11.1, (e) change the amount or term of any of the Banks' Revolving
Credit Commitments or the fees required under Section 3.2 or the L/C
Participation Fee required under Section 1.5(a) hereof, or (f) alter, modify or
amend any Bank's right hereunder to consent to any action, make any request or
give any notice.  Any such amendment or waiver shall apply equally to all Banks
and the holders of the Notes and Reimbursement Obligations and shall be binding
upon them, upon each future holder of any Note and Reimbursement Obligation and
upon the Borrower, whether or not such Note shall have been marked to indicate
such amendment or waiver.  No such amendment or waiver shall extend to or affect
any obligation not expressly amended or waived.

          Section 11.2.  Waiver of Rights.  No delay or failure on the part of
the Administrative Agent or any Bank or on the part of the holder or holders of
any Note or Reimbursement Obligation in the exercise of any power or right shall
operate as a waiver thereof, nor as an acquiescence in any Potential Default or
Event of Default, nor shall any single or partial exercise of any power or right
preclude any other or further exercise thereof, or the exercise of any other
power or right, and the rights and remedies hereunder of the Administrative
Agent, the Banks and of the holder or holders of any Notes are cumulative to,
and not exclusive of, any rights or remedies which any of them would otherwise
have.
<PAGE>
 
          Section 11.3.  Several Obligations.  The commitments of each of the
Banks hereunder shall be the several obligations of each Bank and the failure on
the part of any one or more of the Banks to perform hereunder shall not affect
the obligation of the other Banks hereunder, provided that nothing herein
contained shall relieve any Bank from any liability for its failure to so
perform.  In the event that any one or more of the Banks shall fail to perform
its commitment hereunder, all payments thereafter received by the Administrative
Agent on the principal of Loans and Reimbursement Obligations hereunder, shall
be distributed by the Administrative Agent to the Banks making such additional
Loans ratably as among them in accordance with the principal amount of
additional Loans made by them until such additional Loans shall have been fully
paid and satisfied.  All payments on account of interest shall be applied as
among all the Banks ratably in accordance with the amount of interest owing to
each of the Banks as of the date of the receipt of such interest payment.

          Section 11.4.  Non-Business Day.  If any payment of principal or
interest on any Loan shall fall due on a day which is not a Business Day,
interest at the rate such Loan bears for the period prior to maturity shall
continue to accrue on such principal from the stated due date thereof to and
including the next succeeding Business Day on which the same is payable.

          Section 11.5.  Documentary Taxes.  The Borrower agrees to pay any
documentary or similar taxes with respect to the Loan Documents, including
interest and penalties, in the event any such taxes are assessed irrespective of
when such assessment is made and whether or not any credit is then in use or
available hereunder.

          Section 11.6.  Representations.  All representations and warranties
made herein or in certificates given pursuant hereto shall survive the execution
and delivery of this Agreement and of the Notes, and shall continue in full
force and effect with respect to the date as of which they were made and as
reaffirmed on the date of each borrowing, request for L/C and as long as any
credit is in use or available hereunder.

          Section 11.7.  Notices.  Unless otherwise expressly provided herein,
all communications provided for herein shall be in writing or by telecopy and
shall be deemed to have been given or made when served personally, when an
answer back is received in the case of notice by telecopy or 3 Business Days
after the date when deposited in the United States mail addressed if to the
Borrower to P.O Box 388, Yazoo City, Mississippi,  39194, Attention:  Corporate
Secretary; if to the Administrative Agent or Harris at 111 West Monroe Street,
Chicago, Illinois 60690, Attention:  Agribusiness Group; and if to any of the
Banks, at the address for each Bank set forth under its signature hereon; or at
such other address as shall be designated by any party hereto in a written
notice to each other party pursuant to this Section 11.7.

          Section 11.8.  Costs and Expenses; Indemnity.  (a) The Borrower
agrees to pay on demand and upon receipt of supporting statements, all
reasonable costs and expenses of the Administrative Agent, in connection with
the negotiation, preparation, execution and delivery of this Agreement, the
Notes and the other instruments and documents to be delivered hereunder or in
connection with the transactions contemplated hereby, including the reasonable
fees and expenses of Messrs. Chapman and Cutler, special 
<PAGE>
 
counsel to the Administrative Agent (such fees and expenses of such special
counsel shall not exceed the amount previously agreed to by the Borrower and the
Administrative Agent); all reasonable costs and expenses of the Administrative
Agent, the Banks and any other holder of any Note or any Reimbursement
Obligation (including reasonable attorneys' fees) incurred while any Potential
Default or Event of Default shall have occurred and be continuing, all
reasonable costs and expenses incurred by the Administrative Agent in connection
with any consents or waivers hereunder or amendments hereto, and all reasonable
costs and expenses (including reasonable attorneys' fees), if any, incurred by
the Administrative Agent, the Banks or any other holders of a Note or any
Reimbursement Obligation in connection with the enforcement of this Agreement or
the Notes and the other instruments and documents to be delivered hereunder. The
Borrower agrees to indemnify and save harmless the Banks and the Administrative
Agent from any and all liabilities, losses, reasonable costs and expenses
incurred by the Banks or the Administrative Agent in connection with any action,
suit or proceeding brought against the Administrative Agent or any Bank by any
Person which arises out of the transactions contemplated or financed hereby or
by the Notes, or out of any action or inaction by the Administrative Agent or
any Bank hereunder or thereunder, except for such thereof as is caused by the
gross negligence or willful misconduct of the party indemnified.

       (b) Without limiting the generality of the foregoing, the Borrower
unconditionally agrees to forever indemnify, defend and hold harmless, the Agent
and each Bank, and covenant not to sue for any claim for contribution against,
the Agent or any Bank for any damages, reasonable costs, loss or reasonable
expense, including without limitation, response, remedial or removal costs,
arising out of any of the following:  (i) any presence, release, threatened
release or disposal of any hazardous or toxic substance or petroleum by the
Borrower or any Subsidiary or otherwise occurring on or with respect to its
Property, (ii) the operation or violation of any Environmental Law, whether
federal, state, or local, and any regulations promulgated thereunder, by the
Borrower or any Subsidiary or otherwise occurring on or with respect to its
Property, (iii) any claim for personal injury or property damage in connection
with the Borrower or any Subsidiary or otherwise occurring on or with respect to
its Property, and (iv) the inaccuracy or breach of any environmental
representation, warranty or covenant by the Borrower made herein or in any loan
agreement, promissory note, mortgage, deed of trust, security agreement or any
other instrument or document evidencing or securing any indebtedness,
obligations or liabilities of the Borrower owing to the Agent or any Bank or
setting forth terms and conditions applicable thereto or otherwise relating
thereto, except for damages arising from the Agent's or such Bank's willful
misconduct or gross negligence.  This indemnification shall survive the payment
and satisfaction of all indebtedness, obligations and liabilities of the
Borrower owing to the Agent and the Banks and the termination of this Agreement,
and shall remain in force beyond the payment or satisfaction in full of any
single claim under this indemnification.  This indemnification shall be binding
upon the successors and assigns of the Borrower and shall inure to the benefit
of Agent and the Banks and their respective directors, officers, employees,
agents, and collateral trustees, and their successors and assigns.
<PAGE>
 
          (c) The provisions of this Section 11.8 shall survive payment of the
Notes and Reimbursement Obligations and the termination of the Revolving Credit
Commitments hereunder.

          Section 11.9.  Counterparts.  This Agreement may be executed in any
number of counterparts and all such counterparts taken together shall be deemed
to constitute one and the same instrument.  One or more of the Banks may execute
a separate counterpart of this Agreement which has also been executed by the
Borrower, and this Agreement shall become effective as and when all of the Banks
have executed this Agreement or a counterpart thereof and lodged the same with
the Administrative Agent.

          Section 11.10.  Successors and Assigns; Governing Law; Entire
Agreement.  This Agreement shall be binding upon the Borrower, the
Administrative Agent and the Banks and their respective successors and assigns,
and shall inure to the benefit of the Borrower, the Administrative Agent and
each of the Banks and the benefit of their respective successors and assigns,
including any subsequent holder of any Note or Reimbursement Obligation.  This
Agreement and the rights and duties of the parties hereto shall be construed and
determined in accordance with the internal laws of the State of Illinois.  This
Agreement constitutes the entire understanding of the parties with respect to
the subject matter hereof and any prior agreements, whether written or oral,
with respect thereto are superseded hereby.  The Borrower may not assign any of
its rights or obligations hereunder without the written consent of the Banks.

          Section 11.11.  No Joint Venture.  Nothing contained in this Agreement
shall be deemed to create a partnership or joint venture among the parties
hereto.

          Section 11.12.  Severability.  In the event that any term or provision
hereof is determined to be unenforceable or illegal, it shall be deemed severed
herefrom to the extent of the illegality and/or unenforceability and all other
provisions hereof shall remain in full force and effect.

          Section 11.13.  Table of Contents and Headings.  The table of contents
and section headings in this Agreement are for reference only and shall not
affect the construction of any provision hereof.

          Section 11.14.  Sharing of Payments.  Each Bank agrees with each other
Bank that if such Bank shall receive and retain any payment, whether by set-off
or application of deposit balances or otherwise ("Set-Off"), on any Loan,
Reimbursement Obligation or other amount outstanding under this Agreement or the
other Loan Documents in excess of its ratable share of payments on all Loans,
Reimbursement Obligations and other amounts then outstanding to the Banks, then
such Bank shall purchase for cash at face value, but without recourse (except
for defects in title), ratably from each of the other Banks such amount of the
Loans held by each such other Bank (or interest therein) as shall be necessary
to cause such Bank to share such excess payment ratably with all the other
Banks; provided, however, that if any such purchase is made by any Bank, and if
such excess payment or part thereof is 
<PAGE>
 
thereafter recovered from such purchasing Bank, the related purchases from the
other Banks shall be rescinded ratably and the purchase price restored as to the
portion of such excess payment so recovered, but without interest. Each Bank's
ratable share of any such Set-Off shall be determined by the proportion that the
aggregate principal amount of Loans and Reimbursement Obligations and other
amounts then due and payable to such Bank bears to the total aggregate principal
amount of Loans and Reimbursement Obligations and other amounts then due and
payable to all the Banks.

          Section 11.15. Jurisdiction; Venue.  The Borrower hereby submits to
the nonexclusive jurisdiction of the United States District Court for the
Northern District of Illinois and of any Illinois court sitting in Chicago for
purposes of all legal proceedings arising out of or relating to this Agreement
or the transactions contemplated hereby.  The Borrower irrevocably waives, to
the fullest extent permitted by law, any objection which it may now or hereafter
have to the laying of the venue of any such proceeding brought in such a court
and any claim that any such proceeding brought in such a court has been brought
in an inconvenient forum.

          Section 11.16.  Participants and Note Assignees.  Each Bank shall have
the right at its own cost to grant participations (to be evidenced by one or
more agreements or certificates of participation) in the Loans made, and/or
Reimbursement Obligations, participations in L/Cs and Revolving Credit
Commitment held, by such Bank at any time and from time to time, and to assign
its rights under such Reimbursement Obligations, participations, Loans or the
Notes evidencing such Loans to one or more other Persons; provided that (i) no
such participation or assignment shall relieve any Bank of any of its
obligations under this Agreement, (ii) no such assignee or participant shall
have any rights under this Agreement except as provided in this Section 11.16,
and (iii) the Administrative Agent shall have no obligation or responsibility to
such participant or assignee, except that nothing herein is intended to affect
the rights of an assignee of a Note to enforce the Note assigned.  Any party to
which such a participation or assignment has been granted shall have the
benefits of Section 1.9 and Section 9.3, but shall not be entitled to receive
any greater payment under either such Section than the Bank granting such
participation or assignment would have been entitled to receive in connection
with the rights transferred.  Any agreement pursuant to which any Bank may grant
such a participating interest shall provide that such Bank shall retain the sole
right and responsibility to enforce the obligations of the Borrower hereunder,
including, without limitation, the right to approve any amendment, modification
or waiver of any provision of this Agreement; provided that such participation
agreement may provide that such Bank will not agree to any modification,
amendment or waiver of this Agreement that would (A) increase any Revolving
Credit Commitment of such Bank if such increase would also increase the
participant's obligations, (B) forgive any amount of or postpone the date for
payment of any principal of or interest on any Loan or Reimbursement Obligation
or of any fee payable hereunder in which such participant has an interest or (C)
reduce the stated rate at which interest or fees in which such participant has
an interest accrue hereunder.

          Section 11.17.  Assignment of Commitments by Banks.  Each Bank shall
have the right at any time, with the written consent of the Borrower and the
Administrative Agent (which consent will not be 
<PAGE>
 
unreasonably withheld) to assign all or any part of its Revolving Credit
Commitment to one or more other Persons; provided that (i) each such assignment
shall be of a constant, and not a varying, percentage of all such rights and
obligations, (ii) unless both parties to the assignment are Banks immediately
prior to giving effect to the assignment, the amount of the Revolving Credit
Commitment of the assigning Bank being assigned pursuant to each such assignment
(determined as of the date of such assignment) shall not be less than
$10,000,000 (or if less, the entire amount of such Bank's Revolving Credit
Commitment, or $1,000,000 if such assignment is from one Bank to another) and
shall be an integral multiple of $1,000,000, (iii) the parties to each such
assignment shall execute and deliver to the Administrative Agent, for its
acceptance and recording, an assignment and acceptance, together with any Notes
subject to such assignment, and (iv) neither the consent of the Borrower nor of
the Administrative Agent shall be required for any Bank to assign all or part of
its Revolving Credit Commitment to any affiliate of the assigning Bank or to any
Bank; provided further, however, that each such assigning Bank, unless assigning
all of its Revolving Credit Commitment hereunder, maintains a minimum Revolving
Credit Commitment hereunder in an amount not less than $10,000,000. Upon any
such assignment (except any assignment made pursuant to Sections 1.1(d) or
9.7(b) hereof), its notification to the Administrative Agent and the payment of
a $3,000 recordation fee to the Administrative Agent, the assignee shall become
a Bank hereunder, all Loans and the Revolving Credit Commitment it thereby holds
shall be governed by all the terms and conditions hereof, and the Bank granting
such assignment shall have its Revolving Credit Commitment, and its obligations
and rights in connection therewith, reduced by the amount of such assignment and
Section 1.1(b) hereof shall be automatically amended, without further action, to
reflect the addition of such assignee as a Bank and the reduction of the
Revolving Credit Commitment of the assignor as described in such assignment.
<PAGE>
 
     Upon your acceptance hereof in the manner hereinafter set forth, this
Agreement shall be a contract between us for the purposes hereinabove set forth.

     Dated as of November 25, 1997.

                         Mississippi Chemical Corporation

                         By  /s/ Timothy A. Dawson
                             Its
<PAGE>
 
     Accepted and Agreed to as of the day and year last above written.

                         Harris Trust And Savings Bank individually and as
                            Administrative Agent

                         By  /s/ Brian J. Moeller
                             Its Senior Vice President

                         Address:    111 West Monroe Street
                                     Chicago, Illinois 60690
                         Attention:  Agribusiness Division

                         Eurodollar Lending Office:
                         Nassau Branch
                         111 West Monroe Street
                         Chicago, Illinois  60603

                         Credit Agricole Indosuez

                         By  /s/ Dean Balice
                             Its Senior Vice President
                                 Branch Manager

                         By  /s/ David Bouhl, F.V.P.
                             Its  Head of Corporate Banking
                                  Chicago

                         Address:    55 East Monroe
                                     Chicago, Illinois  60603-5702
                         Attention:  Mr. Ted Tice

                         Eurodollar Lending Office:
                         _______________________
                         _______________________
<PAGE>
 
                         Banque Nationale de Paris, Houston Agency

                         By  /s/ David P. Camp
                             Its Banking Officer

                         Address:    717 North Harwood Street
                                     Suite 2630
                                     Dallas, Texas  75201
                         Attention:  David P. Camp

                         Eurodollar Lending Office:
                         333 Clay Street, Suite 3400
                         Houston, Texas  77002

                         The Fuji Bank, Limited

                         By  /s/ Toshihiro Mitsui
                             Its Senior Vice President & Senior Manager

                         Address:    Suite 2100
                                     The Marquis One Tower
                                     245 Peachtree Center Ave. NE
                                     Atlanta, Georgia  30303
                         Attention:  ____________________

                         Eurodollar Lending Office:
                         _______________________
                         _______________________
<PAGE>
 
                         Bank of America National Trust and Savings Association

                         By  /s/ W. Thomas Barnett
                             Its  Managing Director

                         Address:    231 South LaSalle Street
                                     Chicago, Illinois  60697
                         Attention:  W. Tom Barnett

                         Eurodollar Lending Office:
                         231 South LaSalle Street
                         Chicago, Illinois  60697

                         The Bank of Nova Scotia, Atlanta Agency

                         By  /s/ F. C. H. Asby
                             Its  Senior Manager
                                  Loan Operations

                         Address:    Suite 2700
                                     600 Peachtree St., N.E.
                                     Atlanta, Georgia  30308
                         Attention:  _____________________

                         Eurodollar Lending Office:
                         Suite 2700
                         600 Peachtree St., N.E.
                         Atlanta, Georgia  30308
<PAGE>
 
                         SunTrust Bank, Atlanta

                         By  /s/ Gregory L. Cannon
                             Its  Vice President

                         By  /s/ William McCaleb
                             Its  Banking Officer

                         Address:    25 Park Place
                                     25th Floor
                                     Atlanta, Georgia  30303
                         Attention:  Greg Cannon

                         Eurodollar Lending Office:
                         _______________________
                         _______________________

                         First Union National Bank

                         By  /s/ David Hall
                             Its  SVP/Credit

                         Address:    301 South College Street
                                     Fifth Floor
                                     Charlotte, North Carolina
                                     28288-0745
                         Attention:  Mr. David Hall

                         Eurodollar Lending Office:
                         _______________________
                         _______________________
<PAGE>
 
                         ABN AMRO Bank N.V.

                         By  /s/ Scott D. Austensen
                             Its  VP

                         By  L. K. Kelley
                             Its  GVP

                         Address:    1 Ravinia Drive
                                     Suite 1200
                                     Atlanta, Georgia  30346
                         Attention:  Michael VanCranenburgh

                         Eurodollar Lending Office:
                         _______________________
                         _______________________

                         The Dai-Ichi Kangyo Bank, Ltd.

                         By  /s/ T. Kurita
                             Its

                         Address:    ____________________
                                     1100 Louisiana Street
                                     Suite 4940
                                     Houston, Texas  77002
                         Attention:  Warren Ross

                         Eurodollar Lending Office:
                         One World Trade Center
                         Suite 4911
                         New York, New York  10048
<PAGE>
 
                         Deposit Guaranty National Bank

                         By  /s/ Stanley A. Herran
                             Its  Senior Vice President

                         Address:    210 East Capital
                                     Suite 1180
                                     Jackson, Mississippi 39201
                         Attention:  Stanley A. Herren

                         Eurodollar Lending Office:
                         _______________________
                         _______________________
<PAGE>
 
                                   EXHIBIT A
                        MISSISSIPPI CHEMICAL CORPORATION
                             REVOLVING CREDIT NOTE

                                                            November 25, 1997

     For Value Received, the undersigned, Mississippi Chemical Corporation, a
Mississippi corporation (the "Borrower"), hereby promises to pay to the order of
________________ (the "Bank") on the Termination Date (as defined in the Credit
Agreement hereinafter referred to), at the principal office of Harris Trust and
Savings Bank in Chicago, Illinois, the aggregate unpaid principal amount of all
Loans made by the Bank to the Borrower under the Credit Agreement hereinafter
mentioned and remaining unpaid on the Termination Date, together with interest
on the principal amount of each Loan from time to time outstanding hereunder at
the rates, and payable in the manner and on the dates specified in said Credit
Agreement.

     The Bank shall record on its books or records or on a schedule to this Note
which is a part hereof the principal amount of each Loan made to the Borrower
under the Credit Agreement, all payments of principal and interest thereon and
the principal balances from time to time outstanding; provided that prior to the
transfer of this Note all such amounts shall be recorded on the schedule
attached to this Note.  The record thereof, whether shown on such books or
records or on a schedule to this Note, shall be prima facie evidence as to all
such amounts; provided, however, that the failure of the Bank to record any of
the foregoing shall not limit or otherwise affect the obligation of the Borrower
to repay all Loans made to it under the Credit Agreement, together with accrued
interest thereon.

     This Note is one of the Revolving Credit Notes referred to in and issued
under that certain Credit Agreement dated as of November 25, 1997, among the
Borrower, Harris Trust and Savings Bank, as Administrative Agent, and the Banks
named therein, as amended from time to time (the "Credit Agreement") and shall
be subject to the terms and conditions thereof.  All defined terms used in this
Note, except terms otherwise defined herein, shall have the same meaning as such
terms have in said Credit Agreement.

     Prepayments may be made, and are sometimes required to be made, on any Loan
evidenced hereby and this Note (and the Loans evidenced hereby) may be declared
due prior to the expressed maturity thereof, all in the events, on the terms and
in the manner as provided for in said Credit Agreement.
<PAGE>
 
     The undersigned hereby waives presentment for payment and demand.

     This Note is governed by and shall be construed in accordance with the
internal laws of the State of Illinois.

                                     Mississippi Chemical Corporation

                                     By
                                         Its
<PAGE>
 
                                   EXHIBIT B

                APPLICATION AND AGREEMENT FOR LETTERS OF CREDIT
<PAGE>
 
                                   EXHIBIT C
                         BID LOAN REQUEST CONFIRMATION

[Date]

Harris Trust and Savings Bank,
 as Administrative Agent for the Banks party
 to the Credit Agreement
 referred to below

Attention: __________________

Dear ________________:

     The undersigned, Mississippi Chemical Corporation (the "Borrower") refers
to the Credit Agreement dated as of November 25, 1997, as amended (the "Credit
Agreement"), among the Borrower, the Banks named therein, Harris Trust and
Savings Bank, as Administrative Agent for the Banks and Bank of Montreal, as
Syndication Agent.  Capitalized terms used and not defined herein have the
meanings assigned to them in the Credit Agreement.  The Borrower hereby confirms
that it has, on the date hereof, given you notice pursuant to Section 2.2 of the
Credit Agreement that it requests a Bid Loan Borrowing under the Credit
Agreement, and in that connection sets forth below the terms on which such Bid
Loan Borrowing is requested to be made:

(A) Type of Bid Loan Borrowing/1/                             ________________
--------------------------------------------------------------------------------
(B) Date of Bid Loan Borrowing/2/                             ________________
--------------------------------------------------------------------------------
(C) Aggregate Principal Amount of Bid         Stated Rate        Eurodollar
 Loan Borrowing/3/                            -----------        ----------
                                            _______________     ______________
--------------------------------------------------------------------------------

---------------
/1/  Stated Rate or Eurodollar.

/2/  The Bid Loan Request Confirmation must be received on a Business Day by the
     Agent not later than 2:30 p.m. on the Business Day preceding the proposed
     Auction Date.

/3/  Not less than $5,000,000 and in integral multiples of $1,000,000.
<PAGE>
 
(D) Maturities/4/                   _______________         _______________
                                    _______________         _______________
                                    _______________         _______________
-------------------------------------------------------------------------------
(E) If applicable, maximum amount   _______________         _______________
    requested for each maturity     _______________         _______________
                                    _______________         _______________
-------------------------------------------------------------------------------

     Upon acceptance of any or all of the Bids offered by Banks in response to
this request, the Borrower shall be deemed to affirm as of such date the
representations and warranties made in the Credit Agreement.

                         Mississippi Chemical Corporation

                         By
                             Its

---------------
/4/  1 to 180 days in the case of Stated Rate Bid Loans and one, two, three,
     four, five or six months in the case of Eurodollar Bid Loans, but never
     beyond the Termination Date.

<PAGE>
 
                                   EXHIBIT D
                               INVITATION TO BID

[Name of Bank]                                                         [Date]
[Address]

Attention:

     Reference is made to the Credit Agreement dated as of November 25, 1997
(the "Credit Agreement") among Mississippi Chemical Corporation (the
"Borrower"), the Banks named therein, Harris Trust and Savings Bank, as
Administrative Agent for the Banks.  Capitalized terms used and not defined
herein have the meanings assigned to them in the Credit Agreement.  The Borrower
made a Bid Loan Request on __________, ________ pursuant to Section 2.2(a) of
the Credit Agreement, and in that connection you are invited to submit a Bid by
[Date]/1/.  Your Bid must comply with Section 2.2(c) of the Credit Agreement and
the terms set forth below on which the Bid Loan Request was made.


 
(A)  Type (Stated or Eurodollar)                              ______________
(B)  Date of Proposed Bid Loan Borrowing                      ______________

                                              Stated          Eurodollar
                                              ------          ----------
(C)  Aggregate Principal Amount
     of Bid Loan                              ____________    ______________
(D)  Maturities and maximum
     amount, if different from
     (C), for any maturity                    ____________    ______________


                         Very truly yours,

                         Harris Trust and Savings Bank,
                           as Administrative Agent

                         By
                             Its
---------------
/1/  The Bid must be received by the Administrative Agent by telephone not
     later than 8:45 a.m. Chicago time, on the Auction Date.

<PAGE>
 
                                   EXHIBIT E
                              CONFIRMATION OF BID


Harris Trust and Savings Bank, as                                         [Date]
 Administrative Agent for the Banks party to Credit
 Agreement referred to below

Attention:

     The undersigned [Name of Bank], refers to the Credit Agreement dated as of
November 25, 1997 (the "Credit Agreement") among Mississippi Chemical
Corporation (the "Borrower"), the Banks named therein, Harris Trust and Savings
Bank, as Administrative Agent for the Banks.  Capitalized terms used and not
defined herein have the meanings assigned to them in the Credit Agreement.  The
undersigned hereby confirms that on the date hereof it has made a Bid pursuant
to Section 2.2 of the Credit Agreement, in response to the Bid Loan Request made
by the Borrower on __________, 199____, and in that connection sets forth below
the terms on which such Bid is made:

     Type (Stated Rate or Eurodollar):     _____________________

     Date of proposed Bid Loan Borrowing:  ____________________/2/

                                                   Interest Rate or spread
     Principal Amount/3/         Maturity/4/       over Adjusted LIBOR/5/
     -------------------         -----------       ----------------------



                         Very truly yours,

                         [Name of Bank]

                         By
                              Its

---------------
/2/  As specified in the related Invitation to Bid.
/3/  Principal amount of bid for each maturity may not exceed the principal
     amount requested by the Company or the maximum amount requested for that
     maturity, if less.
/4/  1 to 180 days in the case of Stated Rate Bid Loans and one, two, three,
     four, five or six months in the case of Eurodollar Bid Loans.
/5/  Specify rate of interest per annum computed on the basis of a year of 360
     days and actual days elapsed for Stated Rate Bid Loans and percentage to be
     added to Adjusted LIBOR for Eurodollar Bid Rate Loans.
                                        
<PAGE>
 
                                   EXHIBIT F
                          NOTICE OF ACCEPTANCE OF BID



[Name of Bank]                                                          [Date]
[Address]

Attention:

     Reference is made to the Credit Agreement dated as of November 25, 1997
(the "Credit Agreement") among Mississippi Chemical Corporation (the
"Borrower"), the Banks named therein, Harris Trust and Savings Bank, as
Administrative Agent for the Banks.  Capitalized terms used and not defined
herein have the meanings assigned to them in the Credit Agreement.  The Borrower
made a Bid Loan Request on __________, ______ pursuant to Section 2.2 of the
Credit Agreement, and in that connection you have submitted a Bid.  Your Bid has
been accepted as set forth below.

(A) Type of Bid Loan                           _______________

(B) Date of Bid Loan Borrowing                 _______________

(C) Aggregate principal           Principal
    amount of each Bid              Amount        Maturity      Interest Rate
    maturity and interest rate    ---------       --------      -------------
                                  __________      __________    __________
                                  __________      __________    __________
                                  __________      __________    __________
                                  __________      __________    __________

                         Very truly yours,

                         Harris Trust and Savings Bank,
                           as Administrative Agent

                         By
                             Its
<PAGE>
 
                                   EXHIBIT G
                                  SUBSIDIARIES


    Name of Company                           State of Incorporation
    ---------------                           ----------------------
Mississippi Phosphates Corporation                Delaware
Mississippi Potash, Inc.                          Mississippi
NSI Land Corporation                              Delaware
Mississippi Chemical Management Company           Delaware
Mississippi Chemical Company, L.P.                Delaware
MCC Investments, Inc.                             Delaware
Eddy Potash, Inc.                                 Mississippi
Triad Nitrogen, Inc.                              Delaware
Triad Fertilizer, Inc.                            Mississippi
  (a subsidiary of Triad Nitrogen, Inc.)
TNI, Inc.                                         Mississippi
  (a subsidiary of Triad Nitrogen, Inc.)
Triad Barge, Inc.                                 Mississippi
  (a subsidiary of Triad Nitrogen, Inc.)
TNI Barge, Inc.                                   Delaware
  (a subsidiary of Triad Barge, Inc.)
<PAGE>
 
                                   EXHIBIT H
                             COMPLIANCE CERTIFICATE

     This Compliance Certificate is furnished to Harris Trust and Savings Bank
and the other Banks (collectively, the "Banks") and Harris Trust and Savings
Bank as Administrative Agent (the "Administrative Agent") for the Banks,
pursuant to that certain Credit Agreement dated as of November 25, 1997, by and
among Mississippi Chemical Corporation, a Mississippi corporation (the
"Borrower"), the Administrative Agent and the Banks (the "Agreement").  Unless
otherwise defined herein, the terms used in this Compliance Certificate have the
meanings ascribed thereto in the Agreement.

     The Undersigned Hereby Certifies That:

       1. I am the duly elected [President] or [Chief Financial Officer] of the
Borrower;

       2. I have reviewed the terms of the Agreement and I have made, or have
caused to be made under my supervision, a review of the transactions and
conditions of the Borrower and its Subsidiaries during the accounting period
covered by the attached financial statements sufficient for me to provide this
Certificate;

       3. The examinations described in paragraph 2 did not disclose, and I have
no knowledge of, the existence of any condition or event which constitutes a
Potential Default or Event of Default during or at the end of the accounting
period covered by the attached financial statements or as of the date of this
Certificate, except as set forth below; and

       4. If attached financial statements are being furnished pursuant to
Section 7.4(a) of the Agreement, Schedule I attached hereto sets forth financial
data and computations evidencing the Borrower's compliance with certain
covenants of the Agreement, all of which data and computations are true,
complete and correct.

       Described below are the exceptions, if any, to paragraph 3 by listing, in
detail, the nature of the condition or event, the period during which it has
existed and the action which the Borrower has taken, is taking or proposes to
take with respect to each such condition or event:

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

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

       The foregoing certifications, together with the computations set forth in
Schedule I hereto and the financial statements delivered with this Certificate
in support hereof, are made and delivered this _____ day of __________________,
19___.

 
                         [President] or [Chief Financial Officer of The
                         Borrower]
<PAGE>
 
                                   SCHEDULE 1
                           TO COMPLIANCE CERTIFICATE
                        MISSISSIPPI CHEMICAL CORPORATION

                          COMPLIANCE CALCULATIONS FOR
                 CREDIT AGREEMENT DATED AS OF NOVEMBER 25, 1997

                 CALCULATIONS AS OF ____________________, 19__



I.   Section 7.21 Maximum Leverage Ratio.
             (a)  ____________________..........................    $___________
             (b)  ____________________..........................    $___________
             (c)  ____________________..........................    $___________
             (d)  Leverage Ratio
                  ((a) divided by (c))..........................    ______ to 1*

                  *Required to be not more than ___ to 1

                  Compliance..................   Yes____
                                                 No_____

II.  Section 7.22 Minimum Interest Coverage Ratio.
             (a)  ____________________..........................    $___________
             (b)  ____________________..........................    $___________
             (c)  Interest Coverage Ratio
                  ((a) divided by (b))..........................    ______ to 1*

                  *Required to be not less than ________ to 1

                  Compliance...................  Yes____                      
                                                 No_____
                                                 
III. Section 7.23 Minimum Tangible Net Worth.
             (a)  ____________________..........................    $___________
             (b)  ____________________..........................    $___________
             (c)  Net Worth ((a) plus (b))......................    $__________*

                  *Required to be not less than $_______________

                  Compliance................... Yes____
                                                No_____
<PAGE>
 
IV.  Pricing Ratio.

           (a) ____________________..........................    $___________
           (b) ____________________..........................    $___________
           (c) ____________________..........................    $___________
           (d) Pricing Ratio
               ((a) divided by (b))..........................    _________ to 1
 
<PAGE>
 
                                   EXHIBIT I

                       [HUGHES & LUCE, L.L.P. LETTERHEAD]

                                    November 25, 1997

Harris Trust and Savings Bank                  SunTrust Bank, Atlanta
Chicago, Illinois                              Atlanta, Georgia
 
Credit Agricole Indosuez                       First Union National Bank
Chicago, Illinois                              Charlotte, North Carolina
 
Banque Nationale de Paris, Houston Agency      ABN AMRO Bank N.V.
Dallas, Texas                                  Atlanta, Georgia
 
The Fuji Bank, Limited                         The Dai-Ichi Kangyo Bank, Ltd.
Atlanta, Georgia                               Houston, Texas
 
Bank of America National Trust and Savings     Deposit Guaranty National Bank
 Association                                   Jackson, Mississippi
Chicago, Illinois
 
The Bank of Nova Scotia, Atlanta Agency
Atlanta, Georgia


Ladies and Gentlemen:

          We have served as counsel to Mississippi Chemical Corporation, a
Mississippi corporation (the "Company"), in connection with a revolving credit
facility being made available by you to the Company.  As such counsel, we have
reviewed the corporate proceedings taken to authorize the execution and delivery
of, and have examined executed originals of, the instruments and documents
identified on Exhibit A to this letter (collectively, the "Loan Documents",
individual Loan Documents hereinafter referred to by the designations appearing
on Exhibit A).  Capitalized terms not otherwise defined herein shall have the
meanings ascribed to them in the Loan Documents.  We have also reviewed the
articles of incorporation, charter, by-laws and any other agreements under which
the Company is organized.  We have also reviewed such other instruments and
records and inquired into such other factual matters and matters of law as we
deem necessary or pertinent to the formulation of the opinions hereinafter
expressed.

          In our examination, we have assumed the genuineness of all signatures
(other than those of the Company), the authenticity of all documents submitted
to us as originals and the conformity with authentic original documents of all
documents submitted to us as copies.  When relevant facts were not independently
established, we have relied upon statements of governmental officials and upon
representations made in or pursuant to the Loan Documents and certificates of
appropriate representatives of the Company.

          In rendering the opinions expressed below, we have assumed, with
respect to all of the documents referred to in this opinion letter, that
(except, to the extent set forth in the opinions expressed below, as to the
Company);
<PAGE>
 
               (i) such documents have been duly authorized by, have been duly
     executed and delivered by, and constitute legal, valid, binding and
     enforceable obligations of, all of the parties to such documents;

               (ii) all signatories to such documents have been duly authorized;
     and

               (iii)  all of the parties to such documents are duly organized
     and validly existing and have the power and authority (corporate or other)
     to execute, deliver and perform such documents.

          Based upon and subject to the foregoing and subject also to the
comments and qualifications set forth below, and having considered such
questions of law as we have deemed necessary as a basis for the opinions
expressed below, we are of the opinion that:

          1.  The Company is a corporation validly existing and in good standing
under the laws of its state of incorporation with full and adequate corporate
power and authority to carry on its business as now conducted and the Company is
duly licensed or qualified to do business and in good standing in each
jurisdiction listed on Exhibit B.

          2.  The Company has full right, power and authority to borrow from
you, to execute and deliver the Loan Documents executed by it and to observe and
perform all the matters and things therein provided for.  The execution and
delivery of the Loan Documents executed by the Company does not, nor will the
observance or performance of any of the matters or things therein provided for,
contravene any provision of applicable law, except where such contravention
would not have a material adverse effect on the properties, business, operations
or financial condition of the Company and its Subsidiaries taken as a whole, or
of the articles of incorporation, charter or by-laws of the Company (there being
no other agreements under which the Company is organized) or, to our knowledge,
of any material covenant, indenture or agreement binding upon or affecting the
Company or any of its properties or assets.

          3.  The Loan Documents executed by the Company have been duly
authorized by all necessary corporate action, have been executed and delivered
by the proper officers of the Company and constitute valid and binding
agreements of the Company enforceable against it in accordance with their
respective terms, subject to bankruptcy, insolvency and other similar laws
affecting creditors' rights generally and to principles of equity.

          4.  Based solely upon our review of those statutes, rules and
regulations which in our experience are normally applicable to transactions of
the type provided for by the Loan Documents, no order known to us,
authorization, consent, license or exemption of, or filing or registration with,
any court or governmental department, agency, instrumentality or regulatory
body, whether local, state or federal, is or will be required in connection with
the lawful execution and delivery of the Loan Documents or the observance and
performance by the Company of any of the terms thereof, except such as have been
previously obtained or where the failure to obtain such order, authorization,
consent, license, exemption or make such filing or registration would not result
in a material adverse change in the properties, business, operations or
financial condition of the Company and its Subsidiaries taken as a whole.

          5.  Except as set forth in Schedule 5.3 of the Credit Agreement, to
our knowledge, there is no action, suit, proceeding or investigation at law or
in equity before or by any court or public body pending or threatened against or
affecting the Company or any of its assets and properties which, if adversely
determined, would result in any material adverse change in the properties,
business, operations or financial condition of the Company and its Subsidiaries
taken as a whole.
<PAGE>
 
November 25, 1997
Page 3

          The foregoing opinions are subject to the following comments and
qualifications:

          (A) The enforceability of Section 11.8 of the Credit Agreement (and
any similar provisions in any of the other Loan Documents) may be limited by
laws rendering unenforceable:  (i) indemnification contrary to Federal or state
securities laws and the public policy underlying such laws and (ii) the release
of a party from, or the indemnification of a party against, liability for its
own wrongful or negligent acts under certain circumstances.

          (B) The enforceability of provisions in the Loan Documents to the
effect that terms may not be waived or modified except in writing may be limited
under certain circumstances.

          (C) We express no opinion as to (i) the effect of the laws of any
jurisdictions in which any Bank is located that limit the interest, fees or
other charges such Bank may impose, (ii) Section 11.14 of the Credit Agreement,
(iii) Section 11.15 of the Credit Agreement (and any similar provisions in any
of the other Loan Documents), insofar as such section relates to the subject
matter jurisdiction of the United States District Court for the Northern
District of Illinois to adjudicate any controversy related to the Loan
Documents, and (iv) the waiver of inconvenient forum set forth in Section 11.15
of the Credit Agreement (and any similar provisions in any of the other Loan
Documents) with respect to proceedings in the United States District Court for
the Northern District of Illinois.

          (D) We express no opinion as to the applicability to the obligations
of the Company (or the enforceability of such obligations) of Section 548 of the
Bankruptcy Code or any other provision of law relating to fraudulent
conveyances, transfers or obligations.

          (E) We express no opinion as to usury laws.

          The entirety of the foregoing opinion is limited in all respects to
the existing laws of the State of Texas and the federal laws of the United
States.  To the extent that the matters covered hereby are governed by laws of
states other than the State of Texas, for purposes of this opinion, we have
assumed with your consent that those laws are identical to the laws of the State
of Texas.

          Our opinions are limited to the specific issues addressed herein and
are limited in all respects to documents, laws and facts existing on the date
hereof.  By rendering our opinions, we do not undertake and hereby disavow any
obligation to advise you of any changes in such documents, laws or facts which
may occur after the date hereof.
<PAGE>
 
          At the request of our clients, this opinion letter is, pursuant to
Section 6.3 of the Credit Agreement, provided to you by us in our capacity as
counsel to the Company and may not be relied upon by any Person (other than a
transferee of the Revolving Credit Commitments in accordance with Section 11.17
of the Credit Agreement) for any purpose other than in connection with the
transactions contemplated by the Credit Agreement without, in each instance, our
prior written consent.

                                         Very truly yours,
<PAGE>
 
                                   EXHIBIT A
                                   ---------

                              The Loan Documents
                              ------------------

          All Loan Documents are dated as of November 25, 1997.

          1.  Credit Agreement among the Company, Harris Trust and Savings Bank,
individually ("Harris") and as Administrative Agent (the "Administrative
Agent"), and Bank of Montreal, as Syndication Agent, and Credit Agricole
Indosuez, as Co-Agent (the "Credit Agreement").

          2. Revolving Credit Note of the Company payable to the order of
Harris.

          3. Revolving Credit Note of the Company payable to the order of Credit
Agricole Indosuez.

          4. Revolving Credit Note of the Company payable to the order of Banque
Nationale de Paris, Houston Agency.

          5. Revolving Credit Note of the Company payable to the order of The
Fuji Bank, Limited.

          6. Revolving Credit Note of the Company payable to the order of Bank
of America National Trust and Savings Association.

          7. Revolving Credit Note of the Company payable to the order of The
Bank of Nova Scotia, Atlanta Agency.

          8. Revolving Credit Note of the Company payable to the order of
SunTrust Bank, Atlanta.

          9. Revolving Credit Note of the Company payable to the order of First
Union National Bank.

          10. Revolving Credit Note of the Company payable to the order of ABN
AMRO Bank N.V.

          11. Revolving Credit Note of the Company payable to the order of The
Dai-Ichi Kangyo Bank, Ltd.

          12. Revolving Credit Note of the Company payable to the order of
Deposit Guaranty National Bank.
<PAGE>
 
                                   EXHIBIT B
                                   ---------

                  Jurisdictions in which Company is Qualified
                  -------------------------------------------

                                  Louisiana
                                  Mississippi
                                  New Mexico
<PAGE>
 
                                   EXHIBIT J

                           FARMLAND MISSCHEM PROJECT
                             CONTINGENT OBLIGATIONS

1.   Cost Overrun Guarantee

     As a condition precedent to the making of any disbursements by the lenders,
     ABN AMRO Bank, N.V., as agent for the lenders, has required the execution
     and delivery of a limited guaranty agreement whereby the Borrower agrees to
     provide to the project, Farmland MissChem Limited, the amount necessary to
     complete the construction of the project, up to $15 million (U.S.).  In the
     event that the conversion to the Ex-Im Bank loan does not occur, the
     Borrower will provide up to an additional $10 million, if necessary to
     complete the project conversion, if there are not sufficient funds
     remaining under the Guaranty.  The obligation begins at Funding and
     terminates at Conversion to either the Ex-Im facility or the commercial
     facility.

     Under the EPC Contract with The M.W. Kellogg Company, the sponsors have
     agreed to provide up to $30 million ($15 million each) in cost overrun
     guaranties.  The $15 million committed by the Borrower to cover cost
     overrun guaranties provides satisfaction of the obligations created under
     both the credit documents and the EPC Contract.

2.   Floor Price Obligation Under Offtake Agreement

     Each sponsor has agreed, pursuant to the terms of the Offtake Agreement, to
     pay for each ton of ammonia produced by the project at either (a) market
     price (determined by reference to an index) less 5 percent, or (b) a floor
     price of $120 per ton (years 1-5) and $115 per ton (years 6-12).  If the
     conversion to the Ex-Im financing does not occur, the floor price is based
     on the projected cash cost per ton of ammonia from the project at an
     assumed operating rate.  The obligation continues for two years beyond the
     expiration of the term facility for 12 years to allow for any delays in the
     retirement of the Term debt.

3.   Take or Pay Obligation Under the Offtake Agreement

     The Offtake Agreement requires that the sponsors take 100% (50% by each
     sponsor) of all ammonia produced by the project.  In the event that the
     Borrower does not take its allocation of product when scheduled, the
     Offtake Agreement requires that payment be made at the then-prevailing
     price.  Should the project temporarily stop producing product as a
     consequence of the Borrower's failure to take product, the Borrower is
     obligated to pay for the product and receive a credit against future
     production.

4.   Interest Rate Swap Guaranty Under Contingent Term Facility (Facility 2)

     In the event that the project fails to convert to the Ex-Im facility, then
     the commercial lenders will require of the project the execution of new
     notes in substitution for the Facility 1 notes of each commercial lender.
     During Facility 2, the interest rate increases to LIBOR plus a Eurodollar
     margin ranging from 2% per annum in years 1-3, 2.25% per annum in years 4-
     7, and 2.5% per annum in years 8-10.  The lenders have required that the
     project participate in an interest rate hedging program in order to reduce
     the interest rate risk to the project.  The Borrower is obligated 
<PAGE>
 
     to participate as a swap counterparty in any interest rate hedging
     arrangement that may be required by the lenders of the project. The
     Borrower's liability is limited to its pro rata share of its participation
     as a swap counterparty.

5.   Cost Overrun and Termination Payment Obligations Under EPC Contract

     Under the EPC Contract, the sponsors have agreed to provide up to $30
     million ($15 million each) in cost overrun guaranties.  This obligation is
     identical to the obligation created in the cost overrun guaranty to be
     entered into by the Borrower for the benefit of the lenders.  In addition,
     the Borrower has agreed that in the event of a termination of the EPC
     Contract, this $15 million guaranty will provide funds to pay termination
     damages which may be due to Kellogg under the terms and conditions of the
     EPC Contract.

6.   Obligation to Pay Lender's Expenses

     The sponsors have agreed to pay the expenses of the lenders in connection
     with the financing of the project, which include, but are not limited to,
     lenders' attorneys' fees, the fees for the independent engineer, the
     environmental consultant and the economic analyst.

7.   Debt Service Reserve

     The sponsors have agreed to fund the project's debt service reserve account
     with the posting of a letter of credit in an amount equal to nine months'
     debt service.  The obligation continues until the project's debt service
     reserve account has been fully funded with cash and is equal to nine
     months' debt service.  The Borrower's obligation is 50% of the debt service
     reserve account.
<PAGE>
 
                                   EXHIBIT K
                           PRICING RATIO CERTIFICATE

     This Pricing Ratio Certificate is furnished to Harris Trust and Savings
Bank and the other Banks (collectively, the "Banks") and Harris Trust and
Savings Bank as Administrative Agent (the "Administrative Agent") for the Banks,
pursuant to that certain Credit Agreement dated as of November 25, 1997, by and
among Mississippi Chemical Corporation, a Mississippi corporation (the
"Borrower") and the Banks (the "Agreement").  Unless otherwise defined herein,
the terms used in this Pricing Ratio Certificate have the meanings ascribed
thereto in the Agreement.

     The Undersigned Hereby Certifies That:

       1. I am the duly elected [President] or [Chief Financial Officer] of the
Borrower;

       2. I have reviewed the terms of the Agreement and I have made, or have
caused to be made under my supervision, a review of the transactions and
conditions of the Borrower and its Subsidiaries during the accounting period
covered by the attached financial statements sufficient for me to provide this
Certificate; and

       3. The examinations described in paragraph 2 did not disclose, and I have
no knowledge of, the existence of any condition or event which constitutes a
Potential Default or Event of Default during or at the end of the accounting
period covered by the attached financial statements or as of the date of this
Certificate, except as set forth below.

     Described below are the exceptions, if any, to paragraph 3 by listing, in
detail, the nature of the condition or event, the period during which it has
existed and the action which the Borrower and its Subsidiaries have taken, is
taking or proposes to take with respect to each such condition or event:

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

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

     The foregoing certifications, together with the computations set forth in
Schedule I hereto are made and delivered this _____ day of __________________, 
19___.


                              [President] or [Chief Financial Officer of the
                              Borrower]
<PAGE>
 
                                   SCHEDULE 1
                          TO PRICING RATIO CERTIFICATE
                        MISSISSIPPI CHEMICAL CORPORATION

                         PRICING RATIO CALCULATION FOR
                 CREDIT AGREEMENT DATED AS OF NOVEMBER 25, 1997

                  CALCULATION AS OF ____________________, 19__
Pricing Ratio.

     (a)      __________________.......................$___________
 
     (b)      __________________.......................$___________
 
     (c)      __________________.......................$___________

     (d)      Pricing Ratio
              ((a) divided by (b))   _________ to 1
 
<PAGE>
 
                                   EXHIBIT L


                           EXISTING LETTERS OF CREDIT


             Number                 Amount             Expiry Date
             ------                 ------             -----------
              35690                 $157,334           July 1, 1999
<PAGE>
 
                                  SCHEDULE 5.3

                             LITIGATION DISCLOSURES

1.   Cleve Reber CERCLA Site

     Triad has received and responded to letters issued by the United States
     Environmental Protection Agency ("EPA") under Section 104 of the
     Comprehensive Environmental Response, Compensation and Liability Act
     ("CERCLA") relative to the possible disposition of Triad waste at the
     disposal site identified as the Cleve Reber site in Ascension Parish,
     Louisiana.  It is Triad's position that, based upon available information
     and records, Triad did not utilize the Cleve Reber site for the disposition
     of hazardous material, and it does not appear that Triad has any
     responsibility for investigation and cleanup on this site.  It should be
     noted that the EPA is contemplating an action under the Resource
     Conservation and Recovery Act, Section 7003, as well as the CERCLA action
     mentioned above.  The EPA has issued Section 106 orders against the major
     contributors at the site for cleanup.  They are now engaged in negotiations
     for cleanup.  Two years ago, Triad received a supplemental 104(e) request
     for information from the EPA, indicating the EPA's renewed interest in
     pursuing Potential Responsible Person at the site.  Triad filed a Freedom
     of Information Act request to investigate allegations that some plant trash
     from Triad may have been disposed of at the Cleve Reber site.  In the
     opinion of management, the likelihood of the CERCLA investigation resulting
     in a loss in a material amount is remote.

     In early 1996, a class action suit was brought against Triad and other
     companies allegedly involved in the site based upon toxic torts alleged to
     have resulted from the presence of contaminants at the Cleve Reber site.
     Triad has not been served with process in the case.  In the opinion of
     management, based upon available information, the likelihood that these
     proceedings will result in a loss in a material amount is remote.  The
     Borrower is monitoring the case while awaiting service of process.

2.   Terra International, Inc.

     On August 31, 1995, the Company filed suit in federal court in Mississippi
     against Terra International, Inc. ("Terra"), seeking a declaratory judgment
     and other relief establishing that certain technology relating to the
     design of an ammonium nitrate neutralizer which the Company licensed to
     Terra is not defective and was not the cause of an explosion which occurred
     in 1994 at Terra's Port Neal, Iowa, fertilizer facility.  The Company is
     also seeking damages for defamation based on Terra's public statement
     related to the Company's alleged role in the explosion.  Also, on August
     31, 1995, Terra filed suit in federal court in Iowa against the Company
     seeking damages caused by the explosion.  Terra alleges that the Company
     negligently designed the ammonium nitrate neutralizer technology licensed
     to Terra and that design defect led to the Port Neal explosion.  Discovery
     in this case is underway and is scheduled to run through December 31, 1997.
     Trial is tentatively scheduled to begin in the summer of 1998.  The Company
     intends to vigorously defend itself against Terra's allegations and plans
     to fully prosecute its defamation claim.
<PAGE>
 
                                 SCHEDULE 7.24

                 CERTAIN EXISTING RESTRICTIONS ON SUBSIDIARIES

     Restrictions contained in documents evidencing or governing industrial
revenue bonds issued for the benefit of Mississippi Phosphates Corporation which
restrict the use of the proceeds of such industrial revenue bonds.