<PAGE>
                                                                 EXHIBIT 4.10(f)

                  SIXTH AMENDMENT TO REVOLVING CREDIT AGREEMENT

         THIS SIXTH AMENDMENT TO REVOLVING CREDIT AGREEMENT (this "Amendment"),
dated as of August 19, 2002, 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, the Fourth Amendment to Revolving Credit
Agreement and Second Amendment to Revolver Intercreditor Agreement dated as of
October 10, 2001, the Fifth Amendment to Revolving Credit Agreement dated as of
June 14, 2002, 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 amendment 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. AMENDMENT TO SECTION 7.1.1 OF THE CREDIT AGREEMENT. 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 effect the following amendment) hereby agree that, effective as of the
Amendment Effective Date (as hereinafter

<PAGE>

defined), Clause (k) of Section 7.1.1 of the Credit Agreement is amended by
deleting the date "August 30, 2002" and inserting the date "October 31, 2002" in
lieu thereof.

         SECTION 2. CONDITIONS PRECEDENT. The parties hereto agree that this
Amendment and the amendment to the Credit 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) 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.

         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 any order, injunction, writ or
decree of any Governmental Authority to which any Obligor is a party or its
property is subject, or (iii) violate any applicable law binding on or affecting
any Obligor.

         (b) GOVERNMENTAL AUTHORIZATION. 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
is 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.


                                       2
<PAGE>

         (d) BINDING EFFECT. 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.

         (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 amendment 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 amendment 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").


                                       3
<PAGE>

         (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.

         (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) agree 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) acknowledge and agree that, except as otherwise
expressly provided for in the Credit 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]


                                       4
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         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: