
<PAGE>   1
                                                                EXHIBIT (c)(5)



                                April 23, 1996

VIA FAX (212) 339-0197

The Beacon Group
375 Park Avenue
17th Floor
New York, NY 10152

ATTENTION:  Mr. Robert F. Semmens
            Partner

Dear Mr. Semmens:

        In connection with your consideration of a possible investment in
AMBAR, Inc. (the "Company"), the Company is prepared to make available to you
certain information concerning the business, financial condition, operations,
assets and liabilities of the Company. As a condition to such information being
furnished to you and your directors, officers, employees, agents or advisors
(including, without limitation, attorneys, accountants, consultants, brokers
and financial advisors) (collectively, "Representatives"), you agree to treat
any information concerning the Company (whether prepared by the Company, its
advisors or otherwise and irrespective of the form of communication) which is
furnished to you or to your Representatives now or in the future by or on
behalf of the Company (herein collectively referred to as the "Evaluation
Material") in accordance with the provisions of this letter agreement, and to
take or abstain from taking certain other actions hereinafter set forth.

        The term "Evaluation Material" shall be deemed to include all notes,
analyses, compilations, studies, interpretations or other documents prepared by
you or your Representatives which contain, reflect or are based upon, in whole
or in part, the information furnished to you or your Representatives pursuant
hereto. The term "Evaluation Material" does not include information which (i)
is or becomes generally available to the public other than as a result of a
disclosure by you or your Representatives, (ii) was within your possession
prior to its being furnished to you by or on behalf of the Company pursuant
hereto, provided that the source of such information was not known by you to be
bound by a confidentiality agreement with or other contractual, legal or
fiduciary obligation of confidentiality to the Company or any other party with
respect to such information or (iii) becomes available to you on a
non-confidential basis from a source other than the Company or any of its
Representatives, provided that such source is not bound by a confidentiality
agreement with or other contractual, legal or fiduciary obligation of
confidentiality to the Company or any other party with respect to such
information. 

        You hereby agree that you and your Representatives shall use the
Evaluation Material solely for the purpose of evaluating a possible transaction
between the Company and you, that the Evaluation Material will be kept
confidential and that you and your Representatives will not disclose any of the
Evaluation Material in any manner whatsoever; provided, however, that (i) you
may make any disclosure of such information to which the Company gives its
prior written 
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The Beacon Group
April 23, 1996
Page 2


consent and (ii) any of such information may be disclosed to your
Representatives who need to know such information for the sole purpose of
evaluating a possible transaction with the Company, who agree to keep such
information confidential and who are provided with a copy of this letter
agreement and agree to be bound by the terms hereof to the same extent as if
they were parties hereto. In any event, you shall be responsible for any breach
of this letter agreement by any of your Representatives and you agree, at your
sole expense, to take all reasonable measures (including but not limited to
court proceedings) to restrain your Representatives from prohibited or
unauthorized disclosure or use of the Evaluation Material.

         In addition, you agree that, without the prior written consent of the
Company, you and your Representatives will not disclose to any other person the
fact that the Evaluation Material has been made available to you, that
discussions or negotiations are taking place concerning a possible transaction
involving the Company or any of the terms, conditions or other facts with
respect thereto (including the status thereof), unless in the written opinion of
your counsel such disclosure is required by law and then only with as much prior
written notice to the Company as is practical under the circumstances. Without
limiting the generality of the foregoing, you further agree that, without the
prior written consent of the Company, you will not, directly or indirectly,
enter into any agreement, arrangement or understanding, or any discussions which
might lead to such agreement, arrangement or understanding, with any person
regarding a possible transaction involving the Company, other than the
transactions stipulated in the Schedule 1. The term "person" as used in this
letter agreement shall be broadly interpreted to include the media and any
corporation, partnership, group, individual or other entity.

         In the event that you or any of your Representatives are requested or
required (by oral questions, interrogatories, requests for information or
documents in legal proceedings, subpoena, civil investigative demand or other
similar process) to disclose any of the Evaluation Material, you shall provide
the Company with prompt written notice of any such request or requirement so
that the Company may seek a protective order or other appropriate remedy and/or
waive compliance with the provisions of this letter agreement. If, in the
absence of a protective order or other remedy or the receipt of a waiver by the
Company, you or any of your Representatives are nonetheless, in the written
opinion of your counsel, legally compelled to disclose Evaluation Material to
any tribunal or else stand liable for contempt or suffer other censure or
penalty, you or your Representative may, without liability hereunder, disclose
to such tribunal only that portion of the Evaluation Material which such counsel
advises you is legally required to be disclosed, provided that you exercise your
best efforts to preserve the confidentiality of the Evaluation Material,
including, without limitation, by cooperating with the Company to obtain an
appropriate protective order or other reliable assurance that confidential
treatment will be accorded the Evaluation Material by such tribunal. 

         If you decide that you do not wish to proceed with a transaction with
the Company, you will promptly inform the Company of that decision (the
"Termination Notice"). In that case, or at any time upon the request of the
Company for any reason, you will promptly deliver to the Company all documents
(and all copies thereof) furnished to you or your Representatives by or on
behalf of Company pursuant hereto. In the event of such a decision or request,
all other Evaluation Material prepared by you or your Representatives shall be
destroyed and no copy 
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The Beacon Group
April 23, 1996
Page 3


thereof shall be retained. Notwithstanding the return or destruction of the
Evaluation Material, you and your Representatives will continue to be bound by
your obligations of confidentiality and other obligations hereunder for a
period of one year from the date of the Termination Notice.

        You understand and acknowledge that neither the Company nor any of its
Representatives make any representation or warranty, express or implied, as to
the accuracy or completeness of the Evaluation Material. You agree that neither
the Company nor any of its Representatives shall have any liability to you or
to any of your Representatives relating to or resulting from the use of the
Evaluation Material. Only those representations or warranties which are made in
a final definitive agreement regarding the transactions contemplated hereby,
when, as and if executed, and subject to such limitations and restrictions as
may be specified therein, will have any legal effect.

        You agree that, until the execution of a final definitive agreement
regarding a transaction between us, you will not initiate or maintain contact
with any officer, director, employee, distributor, supplier or customer of the
Company regarding its business operations, prospects or finances, except with
the express written permission of the Company or except as provided herein. It
is understood that the Company will arrange for appropriate contacts for due
diligence purposes. Unless otherwise agreed to by the Company, all (i)
communications regarding a possible transaction, (ii) requests for additional
information, (iii) requests for facility tours or management meetings, and (iv)
discussions or questions regarding procedures, will be submitted or directed to
the Company.

        In consideration of the Evaluation Material being furnished to you, you
hereby further agree that, without the prior written consent of the Board of
Directors of the Company, for a period of two years from the date hereof,
neither you nor any of your affiliates (as such term is defined in Rule 12b-2
of the Securities Exchange Act of 1934, as amended), acting alone or as part of
a group, will acquire or offer or agree to acquire, directly or indirectly, by
purchase or otherwise, any voting securities (or direct or indirect rights or
options to acquire any voting securities) of the Company, or otherwise seek to
influence or control, in any manner whatsoever, the management or policies of
the Company.

        You agree that unless and until a final definitive agreement regarding
a transaction between the Company and you has been executed and delivered,
neither the Company nor you will be under any legal obligation of any kind
whatsoever with respect to such a transaction by virtue of this letter
agreement except for the matters specifically agreed to herein. You further
acknowledge and agree that the Company reserves the right, in its sole
discretion, to reject any and all proposals made by you or any of your
Representatives with regard to a transaction between the Company and you, and
to terminate discussions and negotiations with you at any time.

        It is understood and agreed that no failure or delay by the Company in
exercising any right, power or privilege hereunder shall operate as a waiver
thereof, nor shall any single or partial exercise thereof preclude any other or
further exercise thereof or the exercise of any other right, power or privilege
hereunder.
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The Beacon Group
April 23, 1996
Page 4


        It is further understood and agreed that money damages would not be a
sufficient remedy for any breach of this letter agreement by you or any of your
Representatives and that the Company shall be entitled to equitable relief,
including injunction and specific performance, as a remedy for any such breach.
Such remedies shall not be deemed to be the exclusive remedies for a breach by
you of this letter agreement but shall be in addition to all other remedies
available at law or equity to the Company. In the event of litigation relating
to this letter agreement, if a court of competent jurisdiction determines that
you or any of your Representatives have breached this letter agreement, then
you shall be liable and pay to the Company the reasonable legal fees incurred
by the Company in connection with such litigation, including any appeal 
therefrom.

        This letter agreement shall be governed by and construed in accordance 
with the laws of the State of Louisiana.

        Please confirm your agreement with the foregoing by signing and
returning one copy of this letter to the undersigned, whereupon this letter
agreement shall become a binding agreement between you and the Company.

                                
                                        Very truly yours,

                                        AMBAR, Inc.

                                        By:    /s/  Randolph M. Moity
                                           -------------------------------
                                                 Randolph M. Moity



Accepted and agreed as of
the date first written above:

The Beacon Group

By:  /s/ Robert F. Semmens
    ------------------------
     Name:  Robert F. Semmens
     Title: Partner

