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                                                                     EXHIBIT 4.3

                          FIRST SUPPLEMENTAL INDENTURE


         FIRST SUPPLEMENTAL INDENTURE (this "First Supplemental Indenture"),
dated as of August 18, 1999, among Merkert American Corporation, a Delaware
corporation (the "Successor Company"), Merkert American Co., Inc., a
Massachusetts corporation, United Brokerage Company, a Michigan corporation and
Buckeye Sales & Marketing, Inc., an Ohio corporation (collectively with Merkert
American Co., Inc. and United Brokerage Company, the "New Guarantor
Subsidiaries"), the existing Guarantor Subsidiaries (the "Existing Guarantor
Subsidiaries") under the indenture referred to below, and CHASE BANK OF TEXAS,
NATIONAL ASSOCIATION (formerly known as Texas Commerce Bank, National
Association), a national banking association, as trustee under the indenture
referred to below (the "Trustee").

                              W I T N E S S E T H:

         WHEREAS, Richmont Marketing Specialists Inc. (the "Company") and the
Existing Guarantor Subsidiaries have heretofore executed and delivered to the
Trustee an indenture (the "Indenture"), dated as of December 19, 1997, providing
for the issuance of an aggregate principal amount of up to $150,000,000 of
10 1/8% Senior Subordinated Notes due 2007 (the "Securities");

         WHEREAS, pursuant to an Agreement and Plan of Merger, dated as of April
28, 1999, by and among the Successor Company, the Company and the stockholders
of the Company, the Company has merged with and into the Successor Company;

         WHEREAS, Section 5.01 of the Indenture provides that a successor entity
to the Company is required to execute and deliver to the Trustee a supplemental
indenture pursuant to which the Successor Company shall expressly assume all the
obligations of the Company under the Securities and the Indenture;

         WHEREAS, Section 4.11 of the Indenture provides that under certain
circumstances the Company (or its successor) is required to cause the New
Guarantor Subsidiaries to execute and deliver to the Trustee a supplemental
indenture pursuant to which the New Guarantor Subsidiaries shall unconditionally
guarantee all of the Company's obligations under the Securities and the
Indenture pursuant to a Subsidiary Guarantee on the terms and conditions set
forth herein; and

         WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee, the
Successor Company and the Existing Guarantor Subsidiaries are authorized to
execute and deliver this Supplemental Indenture;

         NOW, THEREFORE, in consideration of the foregoing and for other good
and valuable consideration, the receipt of which is hereby acknowledged, the New
Guarantor Subsidiaries,


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the Successor Company, the Existing Guarantor Subsidiaries and the Trustee
mutually covenant and agree for the equal and ratable benefit of the holders of
the Securities as follows:

         1.       Definitions.

                  (a) Capitalized terms used herein without definition shall
have the meanings assigned to them in the Indenture.

                  (b) For all purposes of this Supplemental Indenture, except as
otherwise herein expressly provided or unless the context otherwise requires:
(i) the terms and expressions used herein shall have the same meanings as
corresponding terms and expressions used in the Indenture; and (ii) the words
"herein," "hereof" and "hereby" and other words of similar import used in this
Supplemental Indenture refer to this Supplemental Indenture as a whole and not
to any particular section hereof.

         2. Assumption of the Company's Obligations. The Successor Company
hereby agrees to assume all the obligations of the Company under the Securities
and the Indenture on the terms and subject to the conditions set forth in the
Indenture, and expressly agrees to be bound by all other applicable provisions
of the Indenture.

         3. Agreement to Guarantee. The New Guarantor Subsidiaries hereby agree,
jointly and severally with all other Guarantor Subsidiaries, to guarantee the
Successor Company's obligations under the Securities and the Indenture on the
terms and subject to the conditions set forth in Article XI and Article XII of
the Indenture and to be bound by all other applicable provisions of the
Indenture.

         4. Effect of Supplemental Indenture. Except as expressly amended
hereby, the Indenture is in all respects ratified and confirmed and all the
terms, conditions and provisions thereof shall remain in full force and effect.
This Supplemental Indenture shall form a part of the Indenture for all purposes,
and every holder of Securities heretofore or hereafter authenticated and
delivered shall be bound hereby.

         5. Governing Law. THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK BUT WITHOUT
GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT
THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

         6. Trustee Makes No Representation. The Trustee makes no representation
as to the validity or sufficiency of this Supplemental Indenture.


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         7. Counterparts. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

         8. Effect of Headings. The Section headings herein are for convenience
only and shall not effect the construction thereof.


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         IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed as of the date first above written.

                                     THE SUCCESSOR COMPANY:

                                     MERKERT AMERICAN CORPORATION,


                                     By: /s/ Gerald R. Leonard
                                         ----------------------------------
                                         Name: Gerald R. Leonard
                                         Title:

                                     THE NEW GUARANTOR SUBSIDIARIES:

                                     MERKERT AMERICAN CO., INC.


                                     By: /s/ Gerald R. Leonard
                                         ----------------------------------
                                         Name: Gerald R. Leonard
                                         Title:

                                     UNITED BROKERAGE COMPANY, INC.


                                     By: /s/ Gerald R. Leonard
                                         ----------------------------------
                                         Name: Gerald R. Leonard
                                         Title:

                                     BUCKEYE SALES & MARKETING, INC.


                                     By: /s/ Gerald R. Leonard
                                         ----------------------------------
                                         Name: Gerald R. Leonard
                                         Title:


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                                     THE EXISTING GUARANTOR SUBSIDIARIES:

                                     MARKETING SPECIALISTS SALES
                                     COMPANY


                                     By: /s/ Nick G. Bouras
                                         ----------------------------------
                                         Name: Nick G. Bouras
                                         Title:

                                     BROMAR, INC.


                                     By: /s/ Nick G. Bouras
                                         ----------------------------------
                                         Name: Nick G. Bouras
                                         Title:

                                     BROKERAGE SERVICES, INC.,


                                     By: /s/ Nick G. Bouras
                                         ----------------------------------
                                         Name: Nick G. Bouras
                                         Title:

                                     ATLAS MARKETING COMPANY, INC.


                                     By: /s/ Nick G. Bouras
                                         ----------------------------------
                                         Name: Nick G. Bouras
                                         Title:

                                     MEATMASTER BROKERAGE, INC.,


                                     By: /s/ Nick G. Bouras
                                         ----------------------------------
                                         Name: Nick G. Bouras
                                         Title:


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                                     THE TRUSTEE

                                     CHASE BANK OF TEXAS, NATIONAL
                                     ASSOCIATION, as Trustee


                                     By: /s/ Mauri J. Cowen
                                         ---------------------------------------
                                         Name: Mauri J. Cowen
                                         Title: Vice President and Trust Officer



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