<PAGE>
                                                                EXHIBIT 4.18(d)


            FOURTH AMENDMENT TO REVOLVING CREDIT AGREEMENT AND SECOND
                 AMENDMENT TO REVOLVER INTERCREDITOR AGREEMENT

         THIS FOURTH AMENDMENT TO REVOLVING CREDIT AGREEMENT AND SECOND
AMENDMENT TO REVOLVER INTERCREDITOR AGREEMENT (this "Amendment"), dated as of
October 10, 2001, is among STERLING CHEMICALS, INC., a Delaware corporation (the
"Company"), STERLING CANADA, INC., a Delaware corporation ("Canada"), STERLING
PULP CHEMICALS US, INC., a Delaware corporation ("Pulp US"), STERLING PULP
CHEMICALS, INC., a Georgia corporation ("Pulp"), STERLING FIBERS, INC., a
Delaware corporation ("Fibers"), STERLING CHEMICALS ENERGY, INC., a Delaware
corporation ("Energy"), and STERLING CHEMICALS INTERNATIONAL, INC., a Delaware
corporation (together with the Company, Canada, Pulp US, Pulp, Fibers and
Energy, collectively, the "Borrowers"), the several Lenders (as such term is
defined in the hereinafter described Credit Agreement) parties to this
Amendment, and THE CIT GROUP/BUSINESS CREDIT, INC., as Administrative Agent for
the Lenders (in such capacity, the "Administrative Agent").

                                    RECITALS:

         A. The Borrowers are parties to a Revolving Credit Agreement dated as
of July 19, 2001 (as amended by the First Amendment to Revolving Credit
Agreement and Revolver Intercreditor Agreement dated as of August 17, 2001, the
Second Amendment to Revolving Credit Agreement and Limited Waiver dated as of
August 29, 2001, the Third Amendment to Revolving Credit Agreement and Limited
Waiver dated as of September 7, 2001, and as the same may be further amended,
modified, restated, supplemented, renewed, extended, increased, rearranged
and/or substituted from time to time, the "Credit Agreement") among the
Borrowers, the Administrative Agent, and the several Lenders from time to time
parties thereto. Capitalized terms used and not otherwise defined herein shall
have the meanings ascribed to them in the Credit Agreement.

         B. The Borrowers have requested that the Lenders amend the Credit
Agreement as hereinafter set forth.

         C. The Lenders parties to this Amendment (which Lenders constitute the
Lenders required to effect the amendments intended hereby) are willing to so
amend the Credit Agreement, subject to the performance and observance in full of
each of the covenants, terms and conditions, and in reliance upon all of the
representations and warranties of the Borrowers, set forth herein.

         NOW, THEREFORE, in consideration of the premises and the covenants,
terms, conditions, representations and warranties herein contained, the parties
hereto agree hereby as follows:

         SECTION 1. AMENDMENTS. Subject to the covenants, terms and conditions
set forth herein and in reliance upon the representations and warranties herein
contained, the Borrowers and the several Lenders parties to this Amendment
(which Lenders constitute the Lenders required to





<PAGE>

effect the following amendments) hereby agree to amend the Credit Agreement and
the Revolver Intercreditor Agreement as set forth below in this Section 1, in
each case effective as of the Amendment Effective Date (as hereinafter defined).

         (a) ADDITION OF DEFINITIONS TO THE CREDIT AGREEMENT. Section 1.1 of the
Credit Agreement is amended by inserting the following definitions in the
appropriate alphabetical position therein:

                  "Appraiser" is defined in Section 5.2.3.

                  "Excess EBITDA" is defined in Section 7.2.7.

                  "Qualified Financial Forecast" is defined in Section 5.2.3.

         (b) AMENDMENTS TO CERTAIN CREDIT AGREEMENT DEFINITIONS. Section 1.1 of
the Credit Agreement is amended by deleting the existing definitions of the
terms described in this Section 1(a) below in their entirety and inserting the
following definitions in lieu thereof:

                  "Borrowing Base Amount" means, at any time, an amount equal to
         the sum of (without duplication) (a) 85% of Eligible Accounts; plus (b)
         on and after the date which is the later to occur of (i) the date of
         entry of the Priming Order and (ii) the date the Borrowers have fully
         complied with the proviso to clause (b) of Section 5.2.3, the product
         of (A) the lesser of (x) $10,000,000 and (y) 33% of Generator
         Receivables multiplied by (B) a fraction the numerator of which is the
         excess, if any, of $40,000,000 over the aggregate amount of any
         reductions in the Current Assets Loan Commitment Amount pursuant to
         clause (b) of Section 3.1.2 as a result of Dispositions of Fixed Assets
         Collateral and the denominator of which is $40,000,000; plus (c) 65% of
         Eligible Inventory; provided, however, that the amount available
         pursuant to clause (c) of this definition shall not at any time exceed
         50% of the Current Assets Loan Commitment Amount at such time. The
         Administrative Agent shall have the right to review computations of the
         Borrowing Base Amount and if, in its reasonable judgment, such
         computations have not been computed in accordance with the terms of
         this Agreement, the Administrative Agent shall have the right to
         correct such errors.

                  "Current Assets" means all of the assets of the Borrowers
         other than the Fixed Assets Collateral; provided, however, except to
         the extent set forth in paragraph H of the Final Order, Current Assets
         shall not include, and, except to the extent set forth in paragraph H
         of the Final Order, the Liens granted to the Administrative Agent for
         the benefit of the Lenders shall not extend to, any causes of action
         arising under Chapter 5 of the Bankruptcy Code or any proceeds thereof.

                  "Current Assets Obligations" means all obligations of every
         kind and nature, including without limitation, principal, fees,
         interest (including interest which accrues after or would accrue but
         for the commencement of any case, proceeding or other action relating
         to the bankruptcy, insolvency or reorganization of the Borrowers),
         expenses, indemnities and all other sums, monetary or otherwise,
         whether absolute or contingent, matured or




                                       2
<PAGE>

         unmatured, of the Borrowers and each other Obligor arising under, in
         connection with or relating to the Current Assets Loans, the Current
         Assets Loan Commitment, any Current Assets Security Document or any
         other Loan Document which secures or guarantees such obligations
         (including obligations under a Rate Protection Agreement where the
         counterparty is a Current Assets Lender or its Affiliate), in each
         case, to the extent such obligations are owed to any Current Assets
         Secured Party.

                  "Final Order" means an order or judgment of the Bankruptcy
         Court after a final hearing pursuant to Section 364 of the Bankruptcy
         Code and Fed. R. Bankr. P. 4001, approving the transactions
         contemplated by the Loan Documents in form and substance acceptable to
         Lenders and the Administrative Agent, in their sole discretion,
         including (i) a finding in favor of the Administrative Agent and the
         Lenders pursuant to 11 U.S.C. Section 364(e), (ii) the grant of a
         Superpriority Claim in favor of the Administrative Agent and the
         Lenders with respect to all of the Obligations, and (iii) granting
         Liens in the Current Assets Collateral and the Fixed Assets Collateral
         securing the Obligations as set forth in Section 7.1.8 and the other
         Loan Documents; and which order or judgment of the Bankruptcy Court has
         not been reversed, stayed or otherwise rendered ineffective or modified
         in any manner (except as may be provided in the Priming Order), and if
         such order is the subject of a pending appeal in any respect, neither
         the making of any Credit Extensions, nor the granting of Superpriority
         Claim status with respect to the Obligations, nor the granting of the
         Liens described hereinabove, nor the performance by any of the
         Borrowers of any of their obligations under this Agreement or any other
         Loan Document or under any other instrument or agreement referred to in
         this Agreement shall be the subject of a presently effective stay
         pending appeal.

                  "Fixed Assets Obligations" means all obligations of every kind
         and nature, including without limitation, principal, fees, interest
         (including interest which accrues after or would accrue but for the
         commencement of any case, proceeding or other action relating to the
         bankruptcy, insolvency or reorganization of the Borrowers), expenses,
         indemnities and all other sums, monetary or otherwise, whether absolute
         or contingent, matured or unmatured, of the Borrowers and each other
         Obligor arising under, in connection with or relating to the Fixed
         Assets Loans, the Fixed Assets Loan Commitment, the Fixed Assets
         Security Documents or any other Loan Document which secures or
         guarantees such obligations (including obligations under a Rate
         Protection Agreement where the counterparty is a Fixed Assets Lender or
         its Affiliate), in each case, to the extent such obligations are owed
         to any Fixed Assets Secured Party.

                  "Minimum Excess Availability" means, at any time (a) prior to
         the date which is the date of entry of the Priming Order, $12,000,000,
         plus the amount of any Availability Reserve (as adjusted from time to
         time pursuant to the terms of the definition thereof and/or clause (e)
         of Section 2.7) and (b) on and after the date of entry of the Priming
         Order, the amount of any Availability Reserve (as adjusted from time to
         time pursuant to the terms of the definition thereof and/or clause (e)
         of Section 2.7), plus, for all purposes of this Agreement other than
         Section 7.2.21, the sum of (x) $6,000,000 plus (y) 15% of the aggregate
         amount of any reductions in the Current Assets Loan Commitment Amount
         pursuant to clause (b) of Section 3.1.2 as a result of Dispositions of
         Fixed Assets Collateral.



                                       3
<PAGE>

                  "Priming Lien" means a security interest in and Lien on the
         Fixed Assets Collateral (other than the Capital Securities of the
         Company) granted, or to be granted, to the Current Assets Secured
         Parties pursuant to the Priming Order to secure up to $40,000,000 in
         Current Assets Obligations, which Lien and security interest is (or
         will be upon entry of the Priming Order) a first-priority security
         interest in and Lien on the Fixed Assets Collateral (other than the
         Capital Securities of the Company), subject to no other prior security
         interests or Liens other than Existing Leases and the Priority Liens
         described in clause (b)(ii)(B)(y) and clause (c) of the definition
         thereof; provided that the Current Assets Obligations secured by the
         Priming Lien shall not exceed $40,000,000 in the aggregate, less the
         aggregate amount of all permanent reductions made from time to time to
         the Current Assets Loan Commitment Amount pursuant to Section 3.1.2(b).

                  "Priming Order" means an order or judgment of the Bankruptcy
         Court after a final hearing pursuant to Section 364 of the Bankruptcy
         Code and Fed. R. Bankr. P. 4001, in form and substance acceptable to
         Lenders and the Administrative Agent, in their sole discretion, which
         grants the Priming Lien and which order or judgment of the Bankruptcy
         Court has not been reversed, stayed or otherwise rendered ineffective
         or modified in any manner, and if such order is the subject of a
         pending appeal in any respect, neither the making of any Credit
         Extensions, nor the granting of Superpriority Claim status with respect
         to the Obligations, nor the granting of the Priming Lien described
         hereinabove, nor the performance by any of the Borrowers of any of
         their obligations under this Agreement or any other Loan Document or
         under any other instrument or agreement referred to in this Agreement
         shall be the subject of a presently effective stay pending appeal.

                  "Priority Liens" means (a) with respect to Fixed Assets
         Obligations, (i) the Liens on the Current Assets Collateral securing
         the Current Assets Obligations and, after the date of entry of the
         Priming Order, the Priming Lien on the Fixed Assets Collateral (other
         than the Capital Securities of the Company) and (ii) the Lien on 65% of
         the Capital Securities of the Foreign Restricted Subsidiaries securing
         the Senior Secured Notes; (b) with respect to Current Assets
         Obligations, (i) for the period prior to (but not on or after) the date
         of entry of the Priming Order, the Liens on (A) the Fixed Assets of the
         Borrowers and the Capital Securities of the Borrowers (other than the
         Company) and the Subsidiaries (other than Unrestricted Subsidiaries)
         securing the Fixed Assets Obligations and the Senior Secured Notes, and
         (B) the Capital Securities of the Company securing the Fixed Assets
         Obligations and the Senior Secured Discount Notes, and (ii) on and
         after the date of entry of the Priming Order, (A) with respect to any
         Current Assets Obligations in excess of the amount of Current Assets
         Obligations secured by the Priming Lien (but in all cases excluding the
         amount of Current Assets Obligations secured by the Priming Lien), the
         Liens on (x) the Fixed Assets of the Borrowers and the Capital
         Securities of the Borrowers (other than the Company) and the
         Subsidiaries (other than Unrestricted Subsidiaries) securing the Fixed
         Assets Obligations and the Senior Secured Notes and (y) the Capital
         Securities of the Company securing the Fixed Assets Obligations and the
         Senior Secured Discount Notes and (B) with respect to any Current
         Assets Obligations secured by the Priming Lien, the Liens on (x) the
         Capital Securities of the Company securing the Fixed Assets Obligations
         and the Senior Secured Discount Notes and (y) 65% of the Capital
         Securities of the Foreign Restricted Subsidiaries securing the Senior
         Secured Notes; and (c) with respect to the




                                       4
<PAGE>

         Obligations, the Lien granted under the agreement with BP Chemicals,
         Inc. described in clause (b), Part 2, Item 7.2.3(c) of the Disclosure
         Schedule.

                  "Superpriority Claim" means, in relation to any Borrower, a
         claim against such Borrower in such Borrower's Case which is a
         superpriority administrative expense claim authorized and established
         by the Bankruptcy Court pursuant to, and having the status prescribed
         by, Sections 364(c) and 507(b) of the Bankruptcy Code and any and all
         statutory provisions cited therein and having priority over any or all
         administrative expenses of the kind specified in Sections 503(b),
         507(b) and 546(c) of the Bankruptcy Code; provided, however, that,
         except to the extent set forth in paragraph H of the Final Order, the
         Superpriority Claim of the Administrative Agent and the Lenders shall
         not extend to any causes of action arising under Chapter 5 of the
         Bankruptcy Code or any proceeds thereof.

                  "Trustee" means The Bank of New York (assignee of Harris Trust
         Company of New York), as trustee under the Senior Secured Note
         Indenture.

         (c) AMENDMENT TO SECTION 3.1.1 OF THE CREDIT AGREEMENT. Clause (f) of
Section 3.1.1 of the Credit Agreement is amended by deleting the reference to
"clause (b)(iii) of Section 3.1.2" in clause (ii) and inserting a reference to
"clause (b)(iv) of Section 3.1.2" in lieu thereof.

         (d) AMENDMENT TO SECTION 3.1.2 OF THE CREDIT AGREEMENT. Clause (b) is
deleted from Section 3.1.2. of the Credit Agreement and the following is
inserted in lieu thereof:

                  "(b) Subject to any applicable terms of the Senior Debt
         Intercreditor Agreement dated as of July 23, 1999 between the Indenture
         Trustee, on behalf of itself and the holders of the Senior Secured
         Notes, and the CIT Group/Business Credit, Inc., as administrative agent
         on behalf of the parties described therein, each prepayment of
         Obligations pursuant to clause (d) and clause (f)(ii) of Section 3.1.1
         shall be applied (i) in the case of a Disposition of Fixed Assets
         Collateral other than the Capital Securities of the Company (A) prior
         to the date of entry of the Priming Order, first, to a mandatory
         prepayment of the outstanding Fixed Assets Obligations until all
         outstanding Fixed Assets Obligations have been repaid in full, and,
         second, to a mandatory prepayment of the outstanding Current Assets
         Obligations until all outstanding Current Assets Obligations have been
         repaid in full, and (B) on and after the date of entry of the Priming
         Order, first, to a mandatory prepayment of outstanding Current Assets
         Obligations until an aggregate amount of $40,000,000 of Current Assets
         Obligations have been repaid, second, to a mandatory prepayment of the
         outstanding Fixed Assets Obligations until all outstanding Fixed Assets
         Obligations have been repaid in full, and, third, to a mandatory
         prepayment of the outstanding Current Assets Obligations until all
         outstanding Current Assets Obligations have been repaid in full; (ii)
         in the case of a Disposition of Capital Securities of the Company,
         first, to a mandatory prepayment of the outstanding Fixed Assets
         Obligations until all outstanding Fixed Assets Obligations have been
         repaid in full, and, second, to a mandatory prepayment of the
         outstanding Current Assets Obligations until all outstanding Current
         Assets Obligations have been




                                       5
<PAGE>

         repaid in full; (iii) in the case of a Disposition of Current Assets
         (other than Dispositions of Capital Securities of Unrestricted
         Subsidiaries), first, to a mandatory prepayment of the outstanding
         Current Assets Obligations until all outstanding Current Assets
         Obligations have been repaid in full (or, with respect to Letters of
         Credit, Cash Collateralized) and, second, to a mandatory prepayment of
         the outstanding Fixed Assets Obligations until all outstanding Fixed
         Assets Obligations have been repaid in full; and (iv) in the case of a
         Disposition of Capital Securities of Unrestricted Subsidiaries or the
         receipt of Net Equity Proceeds of the type described in clause (b) of
         the definition thereof, to the Fixed Assets Obligations and the Current
         Assets Obligations in the order designated by the Company upon receipt
         of same by any Obligor, or if no such designation is received by the
         Administrative Agent prior to or upon receipt of such proceeds, then to
         the Obligations as determined by the Administrative Agent. In the case
         of any Disposition of Fixed Assets Collateral prior to the date of the
         entry of the Priming Order or at any time with respect to a Disposition
         of Capital Securities of the Company, the Fixed Assets Loan Commitment
         Amount shall be automatically and permanently reduced by the aggregate
         amount of the Net Disposition Proceeds; provided that so long as no
         Default or Event of Default then exists, no such reduction shall occur
         with respect to Net Disposition Proceeds from a casualty or
         condemnation of Fixed Assets which are permitted to be used by the
         Borrowers in connection with the restoration or replacement of the
         affected assets in accordance with Section 2.3 of the Mortgages. In the
         case of any Disposition of Fixed Assets Collateral other than the
         Capital Securities of the Company on or after the date of the entry of
         the Priming Order, (1) the Current Assets Loan Commitment Amount shall
         be automatically and permanently reduced by an amount equal to the
         lesser of (x) the aggregate amount of such Net Disposition Proceeds and
         (y) an amount that, when added to all other prior reductions of the
         Current Assets Loan Commitment Amount pursuant to this clause (1),
         equals $40,000,000, and (2) the Fixed Assets Loan Commitment Amount
         shall be automatically and permanently reduced by an amount equal to
         the excess, if any, of the aggregate amount of such Net Disposition
         Proceeds over the aggregate amount of any reduction in the Current
         Assets Loan Commitment Amount pursuant to the foregoing clause (1);
         provided in each case that so long as no Default or Event of Default
         then exists, no such reduction shall occur with respect to Net
         Disposition Proceeds from a casualty or condemnation of Fixed Assets
         which are permitted to be used by the Borrowers in connection with the
         restoration or replacement of the affected assets in accordance with
         Section 2.3 of the Mortgages. Upon the indefeasible payment in cash of
         $40,000,000 in the aggregate of Current Assets Obligations and a
         permanent reduction of the Current Assets Loan Commitment Amount by
         $40,000,000 in the aggregate pursuant to the immediately preceding
         sentence, the Priming Lien shall automatically terminate and be
         released without the necessity of further action by the parties and the
         Administrative Agent shall execute and deliver such documentation as is
         reasonably requested by the Borrowers in order to confirm that such
         termination and release of the Priming Lien has occurred."

         (e) AMENDMENT TO SECTION 5.2.3 OF THE CREDIT AGREEMENT. Section 5.2.3.
of the Credit Agreement is deleted in its entirety and the following is inserted
in lieu thereof:

                  "5.2.3. Financing Order. The Interim Order shall be in full
         force and effect and shall not have been stayed, reversed, modified or
         amended in any respect (other than by the Final Order and Priming Order
         as provided therein and hereinbelow); provided that no Lender shall
         have any obligation to make any Credit Extension if the making of such
         Credit Extension would cause the aggregate amount of all Credit
         Extensions then outstanding,




                                       6
<PAGE>

         either separately or together, to exceed the lesser of (x) $155,000,000
         and (y) the amount thereof which was authorized by the Bankruptcy Court
         in the Interim Order unless:

                           (a) the Administrative Agent and each of the Lenders
                  shall have received a certified copy (or other evidence
                  satisfactory to the Administrative Agent) of the Final Order
                  which (i) as entered, shall be acceptable in form and
                  substance to the Administrative Agent, (ii) shall have been
                  entered into no later than September 14, 2001, and (iii) shall
                  then be in full force and effect, and shall not have been
                  stayed, reversed, modified or amended in any respect; provided
                  in such case that no Lender shall have any obligation to make
                  any Credit Extension if the making of any such Credit
                  Extension would cause the aggregate amount of all Credit
                  Extensions then outstanding, either separately or together, to
                  exceed $155,000,000; or

                           (b) the Administrative Agent and each of the Lenders
                  shall have received a certified copy (or other evidence
                  satisfactory to the Administrative Agent) of the Priming Order
                  which (i) as entered, shall be acceptable in form and
                  substance to the Administrative Agent, and (ii) shall then be
                  in full force and effect, and shall not have been stayed,
                  reversed, modified or amended in any respect; provided that,
                  notwithstanding the foregoing, if the making of any Credit
                  Extension would cause the aggregate amount of all Credit
                  Extensions then outstanding to exceed $170,000,000, no Lender
                  shall have any obligation to make such Credit Extension until
                  the Borrowers shall have (A) previously submitted to the
                  Administrative Agent (i) a Qualified Financial Forecast,
                  together with a written report from the Appraiser addressed to
                  the Administrative Agent and the Lenders stating that it has
                  reviewed such Qualified Financial Forecast and performed the
                  scope of work set forth in its engagement letter with the
                  Administrative Agent and that, in the Appraiser's opinion, the
                  Borrowers' Qualified Financial Forecast, including the
                  Borrowers' outlook for acrylonitrile and styrene, the
                  assumptions and key factors contained in such Qualified
                  Financial Forecast (including the reliability of the sources
                  referred to in such Qualified Financial Forecast for such
                  outlook, assumptions and key factors) and the working capital
                  levels, margins, operating cash flow, and EBITDA reflected
                  therein are all reasonable, and (ii) the most recent set of
                  Projections to be delivered to the Lenders pursuant to Section
                  7.1.1.(o), demonstrating pro forma compliance with Section
                  7.2.7 (at the levels that would be in effect assuming this
                  proviso were satisfied) and Section 7.2.4 throughout the next
                  12 month period, and (B) the Borrowers have otherwise complied
                  with the other provisions of this Section 5.2. To the extent
                  that the Borrowers are unable to satisfy the requirements in
                  clause (A) (i) of the proviso to the immediately preceding
                  sentence with respect to the Qualified Financial Forecast most
                  recently submitted to the Administrative Agent, the Borrowers
                  may from time to time revise and/or replace such Qualified
                  Financial Forecast and re-submit the same to the
                  Administrative Agent for review by the Appraiser in order to
                  attempt to satisfy such proviso; provided that (x) any
                  material revisions to any such Qualified Financial Forecast
                  and all replacement Qualified Financial Forecasts must be in
                  form and substance acceptable to the Approving Lenders, and
                  (y) all such revisions, whether or not material, and any
                  replacement Qualified Financial Forecasts must be acceptable
                  in form and substance to the




                                       7
<PAGE>

                  Administrative Agent. All costs and expenses of the Appraiser
                  shall be paid by the Borrowers as provided in the engagement
                  letter among the Appraiser, the Administrative Agent and the
                  Company dated as of September 14, 2002, (and any subsequent
                  engagement letters).

                  As used in the foregoing paragraph, (a) "Appraiser" means
                  Nexant, Inc. or such other independent appraiser of national
                  standing as may be retained by the Administrative Agent for
                  the benefit of the Lenders (and consented to by the Company,
                  which consent shall not be unreasonably withheld or delayed)
                  and (b) "Qualified Financial Forecast" means the consolidated
                  operating and financial plan of the Company, including a
                  restart of the acrylonitrile production and a turnaround of
                  the styrene facility at the Texas City, Texas plant attached
                  hereto as Exhibit Q, as the same may be revised and/or
                  replaced from time to time pursuant to the penultimate
                  sentence of the foregoing paragraph."

         (f) AMENDMENT TO SECTION 7.2.7 OF THE CREDIT AGREEMENT. Section 7.2.7.
of the Credit Agreement is deleted in its entirety and the following is inserted
in lieu thereof:

                  "7.2.7 Monthly Minimum EBITDA. The Borrowers will not permit
         EBITDA for the Borrowers to be less than (i.e., be a greater negative
         number than those set forth below) the following amounts at the end of
         each of the calendar months set forth below opposite such amounts:

                  Prior to the date that the Borrowers have fully satisfied the
         proviso to clause (b) of Section 5.2.3

<Table>
<Caption>
                  Calendar Month                                        Minimum EBITDA
                  --------------                                        --------------
<S>                                                                     <C>
                  Filing Date through and including August 31, 2001         (7,600,000)
                  September 2001                                            (3,300,000)
                  October 2001                                              (3,900,000)
                  November 2001                                             (3,000,000)
                  December 2001                                             (3,400,000)
                  January 2002                                              (2,500,000)
                  February 2002                                             (4,200,000)
                  March 2002                                                (8,300,000)
                  April 2002                                                (1,000,000)
                  May 2002                                                   1,600,000
                  June 2002                                                  2,800,000
                  Each calendar month thereafter                             5,000,000
</Table>




                                       8
<PAGE>

                  Effective on and after the date that the Borrowers have fully
         satisfied the proviso to clause (b) of Section 5.2.3

<Table>
<Caption>
                  Calendar Month                                         Minimum EBITDA
                  --------------                                         --------------
<S>                                                                      <C>
                  Filing Date through and including August 31, 2001          (7,600,000)
                  September 2001                                             (3,300,000)
                  October 2001                                               (5,300,000)
                  November 2001                                              (5,100,000)
                  December 2001                                              (6,300,000)
                  January 2002                                               (1,900,000)
                  February 2002                                              (1,650,000)
                  March 2002                                                 (2,200,000)
                  April 2002                                                    800,000
                  May 2002                                                    1,600,000
                  June 2002                                                   1,000,000
                  July 2002                                                   4,700,000
                  August 2002                                                 5,000,000
                  September 2002                                              5,000,000
                  October 2002 and each month thereafter                      6,000,000
</Table>

         provided, however, that for each calendar month set forth above that
         the Borrowers' EBITDA exceeds the minimum EBITDA amount set forth above
         opposite such calendar month (i.e., reflects a lower negative number or
         exceeds a positive number), such excess (the "Excess EBITDA") shall be
         carried forward on a cumulative basis to the next calendar month's
         calculation of minimum EBITDA of the Borrowers, provided, further, that
         Excess EBITDA from any calendar month in a given Fiscal Year may only
         be carried forward to a calendar month in the same Fiscal Year."

         (g) AMENDMENT TO SECTION 8.2 OF CREDIT AGREEMENT. Section 8.2 of the
Credit Agreement is amended by deleting the phrase "five (5) Business Days'
notice" and inserting the phrase "seven (7) Business Days' notice" in lieu
thereof.

         (h) ADDITION OF EXHIBIT Q TO THE CREDIT AGREEMENT. A new Exhibit Q is
added to the Credit Agreement in the form attached as Exhibit Q hereto.

         (i) AMENDMENTS TO SECTION 3.3 OF THE REVOLVER INTERCREDITOR AGREEMENT.

                  (i) Paragraph (a) of Section 3.3 of the Revolver Intercreditor
Agreement is deleted in its entirety and the following is inserted in lieu
thereof:

                           "(a) The Administrative Agent (in its capacity as
         secured party for and on behalf of the Current Assets Lenders) shall
         have the sole and exclusive right to sell, transfer or otherwise
         dispose of (i) the Current Assets Collateral and (ii) after the date
         that the Priming Order has been entered, the Fixed Assets Collateral
         (other than the Capital Securities of the Company) up to the amount of
         the Current Assets Obligations which are secured by the Priming Lien,
         in each case in any manner deemed necessary or appropriate by it
         without regard to the security interest or Liens of the Fixed Assets
         Secured Parties and without the Fixed Assets Secured Parties' consent.
         Simultaneously with the sale, transfer or other disposition of all or
         any part of the Collateral described in clauses (i) and (ii) above by
         the Administrative Agent (in its capacity as secured party for and on
         behalf of the Current Assets Lenders), the Administrative Agent shall
         release or otherwise terminate the security




                                       9
<PAGE>

         interests in and Liens on all of such Current Assets Collateral and
         such Fixed Assets Collateral which is held by the Fixed Assets Secured
         Parties."

                  (ii) Paragraph (b) of Section 3.3 of the Revolver
Intercreditor Agreement is amended by deleting the reference to "Section 3.3" in
the first line of such paragraph and inserting the reference "Section 3.3(a)" in
lieu thereof.

                  (iii) Paragraph (d) of Section 3.3 of the Revolver
Intercreditor Agreement is amended by deleting the reference to "Section
3.3(a)(ii)" in the clause (iii) of such paragraph and inserting the reference
"Section 3.3(a)" in lieu thereof.

                  (iv) Paragraph (h) of Section 3.3 of the Revolver
Intercreditor Agreement is deleted in its entirety and the following is inserted
in lieu thereof:

                           "(h) The Current Assets Secured Parties understand
         and agree that, so long as any Fixed Assets Obligations shall not have
         been paid in cash in full and until all Fixed Assets Commitments shall
         have been fully and permanently terminated, the Administrative Agent
         shall, with respect to the Fixed Assets Collateral, accept directions
         only from the Fixed Assets Secured Parties; provided that after the
         date that the Priming Order has been entered, the Administrative agent
         shall, with respect to the Fixed Assets Collateral (other than Capital
         Securities of the Company) accept directions only from the Current
         Assets Secured Parties until either (i) the Priming Lien is no longer
         in effect and outstanding, or (ii) the Current Assets Loan Commitment
         Amount has been reduced pursuant to Section 3.1.2(b) of the Credit
         Agreement by $40,000,000 in the aggregate."

         (j) AMENDMENTS TO SECTION 3.4 OF THE REVOLVER INTERCREDITOR AGREEMENT.

                  (i) Paragraph (c) of Section 3.4 of the Revolver Intercreditor
Agreement is deleted in its entirety and the following is inserted in lieu
thereof:

                           "(c) Each Fixed Assets Lender agrees that if it
         receives (i) Current Assets Liquidation Proceeds or (ii) after the date
         of entry of the Priming Order, Fixed Assets Liquidation Proceeds to
         which it is not entitled pursuant to the terms of this Agreement, then
         such Fixed Assets Lender shall promptly remit such proceeds to the
         Administrative Agent for application in accordance with clause (a) of
         this Section 3.4."

                  (ii) Paragraph (d) of Section 3.4 of the Revolver
         Intercreditor Agreement is deleted in its entirety and the following is
         inserted in lieu thereof:

                           "(d) Each Current Assets Lender agrees that if it
         receives Fixed Assets Liquidation Proceeds to which it is not entitled
         pursuant to the terms of this Agreement, then such Current Assets
         Lender shall promptly remit such proceeds to the Administrative Agent
         for application in accordance with clause (b) of this Section 3.4."

                  (iii) A new Paragraph (e) is added to Section 3.4 of the
         Revolver Intercreditor Agreement that reads as follows:




                                       10
<PAGE>

                           "(e) For purposes of this Section, the terms "Fixed
         Assets Liquidation Proceeds" and "Current Assets Proceeds" shall
         include proceeds of Fixed Assets Collateral or Current Assets
         Collateral, as applicable, received by any party hereto from any source
         whatsoever, including by means of setoff."

         (k) AMENDMENT TO SECTION 4.2 OF THE REVOLVER INTERCREDITOR AGREEMENT.
Paragraph (a) of Section 4.2 of the Revolver Intercreditor Agreement is deleted
in its entirety and the following is inserted in lieu thereof:

                  "(a) Notwithstanding anything to the contrary herein, with
         respect to policies which insure (i) the Current Assets Collateral or,
         (ii) after the date of entry of the Priming Order, the Fixed Assets
         Collateral subject to the Priming Lien, if, pursuant to the Applicable
         Agreements, the Company is required to obtain satisfactory loss payable
         endorsements naming the Current Assets Secured Parties and the Fixed
         Assets Secured Parties, as their interests may appear, as loss payees,
         or with such other designation as the parties hereto may agree, the
         Administrative Agent (in its capacity as secured party for and on
         behalf of the Current Assets Lenders and the Fixed Assets Lenders)
         shall, subject to the Administrative Agent's rights under the
         Applicable Agreements, have the sole exclusive right, as against the
         Fixed Assets Secured Parties, to effect settlement of such insurance
         policy in the event of any loss to any Current Assets Collateral). All
         proceeds of such policy shall be paid to the Administrative Agent and
         apply the proceeds of such policy in accordance with clause (a) of
         Section 3.4."

         SECTION 2. CONDITIONS PRECEDENT. The parties hereto agree that this
Amendment and the amendments to the Credit Agreement and the Revolver
Intercreditor Agreement contained herein shall not be effective until the
satisfaction of each of the following conditions precedent:

         (a) EXECUTION AND DELIVERY OF THIS AMENDMENT. The Administrative Agent
shall have received a copy of this Amendment executed and delivered by each of
the applicable Obligors and by the Approving Lenders.

         (b) REPRESENTATIONS AND WARRANTIES. Each of the representations and
warranties made in this Amendment shall be true and correct on and as of the
Amendment Effective Date as if made on and as of such date, both before and
after giving effect to this Amendment (except to the extent such representations
and warranties relate expressly to an earlier date, which representations and
warranties shall have been true and correct as of such earlier date).

         (c) PAYMENT OF EXPENSES. The Borrowers shall have paid and the
Administrative Agent shall have received all costs and expenses of the
Administrative Agent in connection with the preparation, reproduction,
execution, and delivery of this Amendment and any other documents prepared in
connection herewith, including, without limitation, the reasonable fees and
out-of-pocket expenses of counsel for the Administrative Agent.



                                       11
<PAGE>

         (d) DELIVERY OF DOCUMENTS. The Administrative Agent shall have received
certified copies any documents or instruments reasonably requested by the
Administrative Agent, each in form and substance reasonably satisfactory to the
Administrative Agent.

         (e) APPROVAL BY BANKRUPTCY COURT. The Administrative Agent shall have
received a copy (or such other evidence satisfactory to Administrative Agent) of
the Priming Order which (i) as entered, shall be acceptable in form and
substance to the Administrative Agent and the Lenders, (ii) authorizes the
Borrowers to execute, deliver and to perform their respective obligations under
this Amendment and grants the Priming Lien, (iii) shall have been entered upon a
motion of the Borrowers satisfactory in form and substance to the Administrative
Agent, (iv) shall be in full force and effect, and (v) shall not have been
stayed, reversed, modified or amended in any respect.

         SECTION 3. REPRESENTATIONS AND WARRANTIES. To induce the Administrative
Agent and the several Lenders parties hereto to enter into this Amendment, each
of the Borrowers represents and warrants to the Administrative Agent and the
Lenders as follows:

         (a) AUTHORIZATION; NO CONTRAVENTION. The execution, delivery and
performance by the applicable Obligors of this Amendment have been duly
authorized by all necessary partnership, corporate or limited liability company
action, as applicable, and do not and will not (i) contravene the terms of any
Organic Documents of any Obligor, (ii) conflict with or result in any breach or
contravention of, or (except as contemplated by the Loan Documents or as
otherwise permitted by the Credit Agreement) the creation of any Lien under, any
material contract or indenture entered into or assumed after the Filing Date
that is binding on or affects any Obligor or, upon entry of the Priming Order,
any order, injunction, writ or decree of any Governmental Authority to which any
Obligor is a party or its property is subject, or (iii) upon entry of the
Priming Order, violate any applicable law binding on or affecting any Obligor.

         (b) GOVERNMENTAL AUTHORIZATION. Upon entry of the Priming Order, no
approval, consent, exemption, authorization or other action by, or notice to, or
filing with or approvals required under state blue sky securities laws or by any
Governmental Authority will be necessary or required in connection with the
execution, delivery, performance or enforcement of this Amendment.

         (c) NO DEFAULT. No Default or Event of Default exists under any of the
Loan Documents. No Obligor is in default under or with respect to its Organic
Documents. The execution, delivery and performance of this Amendment shall not
result in any default under any material contract or indenture entered into or
assumed on or after the Filing Date that is binding or affects any Obligor.

         (d) BINDING EFFECT. Upon entry of the Priming Order, this Amendment and
the Credit Agreement as amended hereby constitute the legal, valid and binding
obligations of the Obligors that are parties thereto, enforceable against such
Obligors in accordance with their respective terms, except as enforceability may
be limited by applicable bankruptcy, insolvency, or similar laws affecting the
enforcement of creditors' rights generally or by equitable principles of general
applicability.



                                       12
<PAGE>

         (e) REPRESENTATIONS AND WARRANTIES. The representations and warranties
set forth in the Credit Agreement and the other Loan Documents are true and
correct in all material respects on and as of the Amendment Effective Date, both
before and after giving effect to the amendments contemplated in this Amendment,
as if such representations and warranties were being made on and as of the
Amendment Effective Date (except to the extent such representations and
warranties relate expressly to an earlier date, which representations and
warranties are true and correct as of such earlier date).

         SECTION 4. MISCELLANEOUS

         (a) RATIFICATION AND CONFIRMATION OF LOAN DOCUMENTS. Except for the
specific amendments expressly set forth in this Amendment, the terms,
provisions, conditions and covenants of the Credit Agreement and the other Loan
Documents remain in full force and effect and are hereby ratified and confirmed,
and the execution, delivery and performance of this Amendment shall not in any
manner operate as a waiver of, consent to or amendment of any other term,
provision, condition or covenant of the Credit Agreement or any other Loan
Document.

         (b) FEES AND EXPENSES. The Borrowers jointly and severally agree to pay
on demand all reasonable costs and expenses of the Administrative Agent in
connection with the preparation, reproduction, execution, and delivery of this
Amendment and any other documents prepared in connection herewith, including,
without limitation, the reasonable fees and out-of-pocket expenses of counsel
for the Administrative Agent.

         (c) HEADINGS. Section and subsection headings in this Amendment are
included herein for convenience of reference only and shall not constitute a
part of this Amendment for any other purpose or be given any substantive effect.

         (d) APPLICABLE LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND SHALL BE
CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK,
WITHOUT REGARD TO CONFLICTS OF LAW PRINCIPLES.

         (e) COUNTERPARTS AND AMENDMENT EFFECTIVE DATE. This Amendment may be
executed in any number of counterparts and by different parties hereto in
separate counterparts, each of which when so executed and delivered shall be
deemed an original, but all such counterparts together shall constitute but one
and the same instrument; signature pages may be detached from multiple separate
counterparts and attached to a single counterpart so that all signature pages
are physically attached to the same document. This Amendment shall become
effective when each of the conditions precedent set forth in Section 2 of this
Amendment have been satisfied (the "Amendment Effective Date").

         (f) AFFIRMATION OF OBLIGATIONS. Notwithstanding that such consent is
not required thereunder, the undersigned Obligors hereby consent to the
execution and delivery of this Amendment by the parties hereto and reaffirm
their respective obligations under each of the Loan Documents to which such
Obligors are parties.




                                       13
<PAGE>

         (g) CONFIRMATION OF LOAN DOCUMENTS AND LIENS. As a material inducement
to the Lenders to amend the Credit Agreement, the Obligors that are parties
hereto hereby (i) acknowledge and confirm the continuing existence, validity and
effectiveness of the Loan Documents to which they are parties, including,
without limitation the Security Documents, and the Liens granted under the
Security Documents, (ii) agrees that, except as otherwise expressly provided in
this Amendment, the execution, delivery and performance of this Amendment shall
not in any way release, diminish, impair, reduce or otherwise affect such Loan
Documents and Liens and (iii) acknowledges and agrees that, except as otherwise
expressly provided for in this Amendment with respect to the Priming Order, the
Liens granted under the Security Documents secure payment of the Obligations
under the Loan Documents in the same priority as on the date such Liens were
created and perfected, and the performance and observance by the Borrowers and
the other Obligors of the covenants, agreements and conditions to be performed
and observed by each under the Credit Agreement, as amended hereby.

         (h) FINAL AGREEMENT. THIS AMENDMENT, TOGETHER WITH THE CREDIT AGREEMENT
AND OTHER LOAN DOCUMENTS, REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES AND
MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN
THE PARTIES.


      [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK; SIGNATURE PAGES FOLLOW]



                                       14
<PAGE>


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

                                      OBLIGORS:


                                      STERLING CHEMICALS, INC.


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


                                      STERLING CANADA, INC.


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


                                      STERLING PULP CHEMICALS US, INC.


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


                                      STERLING PULP CHEMICALS, INC.


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


                                      STERLING FIBERS, INC.


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






<PAGE>


                                      STERLING CHEMICALS ENERGY, INC.


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


                                      STERLING CHEMICALS
                                      INTERNATIONAL, INC.


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



                                      STERLING CHEMICALS HOLDINGS, INC.



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



<PAGE>




                                      ADMINISTRATIVE AGENT:

                                      THE CIT GROUP/BUSINESS CREDIT,
                                      INC., as Administrative Agent


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


                                      LENDERS:


                                      THE CIT GROUP/BUSINESS CREDIT, INC.


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


                                      IBJ WHITEHALL BUSINESS CREDIT
                                      CORPORATION


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


                                      FLEET CAPITAL CORPORATION


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


                                      TEXTRON FINANCIAL CORP.


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





<PAGE>


                                      TRANSAMERICA BUSINESS CAPITAL CORPORATION


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


                                      GMAC BUSINESS CREDIT, LLC


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


                                      THE PROVIDENT BANK


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


                                      GPSF SECURITIES, INC.


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


                                      FOOTHILL INCOME TRUST II, L.P.


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


                                      CONGRESS FINANCIAL CORPORATION


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


<PAGE>




                                      COMERICA BANK


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





<PAGE>


                                    EXHIBIT Q

                          Qualified Financial Forecast