
<PAGE>   1
                                                                Exhibit (a)(7)

This announcement is neither an offer to purchase nor a solicitation of an offer
to sell Shares. The Offer is made solely by the Offer to Purchase, dated July 9,
1996, and the related Letter of Transmittal, and is being made to all holders of
Shares. The Purchaser is not aware of any state where the making of the Offer is
prohibited by administrative or judicial action pursuant to any valid state
statute. If the Purchaser becomes aware of any valid state statute prohibiting
the making of the Offer or the acceptance of Shares pursuant thereto, the
Purchaser will make a good faith effort to comply with any such state statute or
seek to have such statute declared inapplicable to the Offer. If, after such
good faith effort, the Purchaser cannot comply with any such state statute, the
Offer will not be made to (nor will tenders be accepted from or on behalf of)
holders of Shares in such state. In any jurisdiction where the securities, blue
sky or other laws require the Offer to be made by a licensed broker or dealer,
the Offer shall be deemed to be made on behalf of the Purchaser by one or more
registered brokers or dealers licensed under the laws of such jurisdiction.

                      NOTICE OF OFFER TO PURCHASE FOR CASH

                     ALL OUTSTANDING SHARES OF COMMON STOCK

                                       OF

                                   AMBAR, INC.

                                       AT
                                $18 NET PER SHARE

                                       BY

                              AI ACQUISITIONS CORP.

                             A CORPORATION FORMED BY

                                THE BEACON GROUP

         AI Acquisitions Corp., a Delaware corporation (the "Purchaser") and a
wholly owned subsidiary of AI Partners L.P. ("Parent"), a Delaware limited
partnership, is offering to purchase all outstanding shares of Common Stock, par
value $.01 per share (the "Shares"), of AMBAR, Inc., a Delaware corporation (the
"Company"), at $18 per Share, net to the seller in cash, without interest
thereon, upon the terms and subject to the conditions set forth in the Offer to
Purchaser, dated July 9, 1996 (the "Offer to Purchase"), and in the related
Letter of Transmittal (which together constitute the "Offer"). The Purchaser and
Parent have been formed by The Beacon Group, a New York general partnership, for
purposes of the transactions described herein. Following the Offer, the
Purchaser intends to effect the Merger described below.

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
TIME, ON MONDAY, AUGUST 5, 1996 UNLESS EXTENDED.
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         THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, (i) THERE BEING
VALIDLY TENDERED AND NOT WITHDRAWN BY THE EXPIRATION DATE (AS DEFINED BELOW) A
NUMBER OF SHARES WHICH REPRESENTS NOT LESS THAN 90% OF THE COMPANY'S COMMON
STOCK OUTSTANDING ON A FULLY DILUTED BASIS AND (ii) CERTAIN OTHER CONDITIONS
CONTAINED IN THE OFFER TO PURCHASE.

         The purpose of the Offer and the Merger is to enable Parent to acquire
control of, and the entire common equity interest in, the Company. The Offer is
being made pursuant to an Agreement of Merger, dated as of July 1, 1996 (the
"Merger Agreement"), among Parent, the Purchaser and the Company. The Merger
Agreement provides, among other things, for the commencement of the Offer by the
Purchaser and further provides that, subject to the satisfaction or waiver of
certain conditions, the Purchaser will be merged with and into the Company (the
"Merger"), with the Company surviving the Merger. Pursuant to the Merger, each
then-outstanding Share not owned by Parent, the Purchaser or any other direct or
indirect subsidiary of Parent (other than Shares held in the treasury of the
Company and Shares held by holders who perfect their appraisal rights as
described in the Offer to Purchase) will be converted into a right to receive in
cash an amount per Share equal to the highest price per Share paid pursuant to
the Offer, without interest thereon, upon surrender of the certificate formerly
representing such Share.

         THE BOARD OF DIRECTORS OF THE COMPANY HAS APPROVED THE OFFER AND THE
MERGER AND DETERMINED THAT THE TERMS OF THE OFFER AND THE MERGER ARE FAIR TO AND
IN THE BEST INTERESTS OF THE COMPANY AND ITS STOCKHOLDERS AND RECOMMENDS THAT
HOLDERS OF SHARES ACCEPT THE OFFER AND TENDER THEIR SHARES PURSUANT TO THE
OFFER.

         For purposes of the Offer, the Purchaser will be deemed to have
accepted for payment, and thereby purchased, Shares validly tendered, if and
when the Purchaser gives oral or written notice to The First National Bank of
Boston, as the Depositary, of the Purchaser's acceptance of such Shares for
payment pursuant to the Offer. In all cases, upon the terms and subject to the
conditions of the Offer, payment for Shares purchased pursuant to the Offer will
be made by deposit of the purchase price therefor with the Depositary, which
will act as agent for tendering stockholders for the purpose of receiving
payment from the Purchaser and transmitting payment to validly tendering
stockholders. Under no circumstances will interest on the purchase price for
Shares be paid by the Purchaser. In all cases, payment for Shares purchased
pursuant to the Offer will be made only after timely receipt by the
Depositary of (i) certificates representing Shares (the "Share Certificates")
(or a timely Book-Entry confirmation), pursuant to the procedures set forth in
Section 3 of the Offer to Purchase, (ii) the Letter of Transmittal (or a
facsimile thereof), properly completed and duly executed, with any required
signature guarantees or an Agent's Message (as defined in the Offer to Purchase)
in connection with a book-entry transfer, and (iii) any other documents required
by the Letter of Transmittal. Upon the terms and subject to the conditions of
the Offer, all Shares validly tendered will be accepted for purchase on the
Expiration Date.

         The term "Expiration Date" means 12:00 midnight, New York City time, on
Monday, August 5, 1996, unless and until the Purchaser (subject to the terms of
the Merger Agreement) shall have extended the period of time during which the
Offer is open, in which event the term "Expiration Date" shall refer to the
latest time and date at which the Offer, as so extended by the Purchaser, will
expire. The Purchaser expressly reserves the right, at any time or from time to
time, subject to the terms of the Merger Agreement, to extend the period of time
during which the Offer is open and thereby delay acceptance for payment of, and
the payment for, any Shares, by giving oral or written notice of such extension
to the Depositary and by making a public announcement thereof by no later than
9:00 a.m. New York City time, on the next business day after the previously
scheduled Expiration Date in accordance with the announcement requirements of
Rule 14d-4(c) under the Securities Exchange Act of 1934, as amended. During any
such extension, all Shares previously tendered and not withdrawn will remain
subject to the Offer, subject to the right of a tendering stockholder to
withdraw such stockholder's Shares. Without limiting the manner in which the
Purchaser may choose to make any public announcement, the Purchaser currently
intends to make such announcement by issuing a press release to the Dow Jones
News Service.

         Except as otherwise provided below, tenders of Shares made pursuant to
the Offer are irrevocable. Shares tendered pursuant to the Offer may be
withdrawn at any time prior to the Expiration Date and, unless theretofore
accepted for payment by the Purchaser, may also be withdrawn at any time after
September 6, 1996. For a withdrawal
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to be effective, a written, telegraphic or facsimile transmission notice of
withdrawal must be timely received by the Depositary at one of its addresses set
forth on the back cover of the Offer to Purchase. Any such notice of withdrawal
must specify the name of the person who tendered the Shares to be withdrawn, the
number of shares to be withdrawn, and the name of the registered holder, if
different from that of the person who tendered such Shares. If certificates for
the Shares have been delivered or otherwise identified to the Depositary, then
(except in the case of Shares tendered for the account of an Eligible
Institution, as defined under "Procedures for Tendering Shares" in the Offer to
Purchase) prior to the release of such certificates, the tendering stockholder
must also submit the serial numbers shown on the particular certificates
evidencing the Shares to be withdrawn, and the signature on the notice of
withdrawal must be guaranteed by an Eligible Institution. If Shares have been
tendered pursuant to the procedure for book-entry transfer set forth under
"Procedures for Tendering Shares" in the Offer to Purchase, the notice of
withdrawal must also specify the name and number of the account at the
appropriate Book-Entry Transfer Facility to be credited with the withdrawn
Shares. All questions as to the form and validity (including time of receipt) of
notices of withdrawal will be determined by the Purchaser, in its sole
discretion, whose determination shall be final and binding. None of the
Purchaser, Parent, the Company, the Depositary, the Information Agent (as set
forth below) or any other person will be under any duty to give notification of
any defects or irregularities in any notice of withdrawal or incur any liability
for failing to give such notification. Any Shares properly withdrawn will be
deemed not validly tendered for purposes of the Offer. However, withdrawn Shares
may be tendered again by following any of the procedures described under
"Procedures for Tendering Shares" in the Offer to Purchase.

         The Company has provided the Purchaser with the Company's stockholder
list and security position listings for the purpose of disseminating the Offer
to holders of Shares. The Offer to Purchase, the related Letter of Transmittal
and other relevant materials will be mailed to record holders of Shares and will
be furnished to brokers, dealers, commercial banks, trust companies and similar
persons whose names, or the names of whose nominees, appear on the Company's
stockholder list or, if applicable, who are listed as participants in a clearing
agency's security position listing, for subsequent transmittal to beneficial
owners of Shares by the Purchaser.

         The information required to be disclosed by Rule 14d-6(e)(1)(vii) of
the General Rules and Regulations under the Securities Exchange Act of 1934, as
amended, is contained in the Offer to Purchase and is incorporated herein by
reference.

         THE OFFER TO PURCHASE AND THE RELATED LETTER OF TRANSMITTAL CONTAIN
IMPORTANT INFORMATION WHICH SHOULD BE READ CAREFULLY BEFORE ANY DECISION IS MADE
WITH RESPECT TO THE OFFER.

         Requests for copies of the Offer to Purchase, the Letter of Transmittal
and other tender offer documents may be directed to the Information Agent, and
copies will be furnished promptly at the Purchaser's expense. Questions or
requests for assistance may be directed to the Information Agent. Except as set
forth under "Fees and Expenses" in the Offer to Purchase, the Purchaser will not
pay any fees or commissions to any broker or dealer or other person (other than
the Depositary and the Information Agent) in connection with the solicitation of
tenders of Shares pursuant to the Offer.

                     The Information Agent for the Offer is:

                                    GEORGESON
                                 & COMPANY INC.
                              --------------------
                                Wall Street Plaza
                            New York, New York 10005
                           (Toll Free) (800) 223-2064

              Brokers and Banks, please call collect (212) 440-9800

July 9, 1996
