
<PAGE>   1
 
                           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
 
THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
TIME, ON MONDAY, AUGUST 5, 1996, UNLESS THE OFFER IS EXTENDED
 
To our Clients:
 
     Enclosed for your consideration are the Offer to Purchase, dated July 9,
1996 (the "Offer to Purchase"), and the related Letter of Transmittal (which
together constitute the "Offer") relating to the offer by AI Acquisitions Corp.,
a Delaware corporation ("Purchaser") formed by The Beacon Group, a New York
general partnership, to purchase all outstanding shares of common stock, par
value $.01 per share (the "Shares"), of AMBAR, Inc., a Delaware corporation (the
"Company"), at a purchase price of $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 Purchase and in the related Letter of Transmittal enclosed
herewith. Holders of Shares whose certificates for such Shares (the "Share
Certificates") are not immediately available or who cannot deliver all required
documents to the Depositary on or prior to the Expiration Date, or who cannot
complete the procedures for book-entry transfer on a timely basis, must tender
their Shares according to the guaranteed delivery procedures set forth in
Section 3 of the Offer to Purchase.
 
     WE ARE THE HOLDER OF RECORD OF SHARES HELD BY US FOR YOUR ACCOUNT. A TENDER
OF SUCH SHARES CAN BE MADE ONLY BY US AS THE HOLDER OF RECORD AND PURSUANT TO
YOUR INSTRUCTIONS. THE LETTER OF TRANSMITTAL IS FURNISHED TO YOU FOR YOUR
INFORMATION ONLY AND CANNOT BE USED BY YOU TO TENDER SHARES HELD BY US FOR YOUR
ACCOUNT.
 
     Accordingly, we request instructions as to whether you wish to have us
tender on your behalf any or all Shares held by us for your account pursuant to
the terms and conditions set forth in the Offer.
 
     Please note the following:
 
          1. The tender price is $18 per Share, net to you in cash without
     interest thereon, upon the terms and subject to the conditions set forth in
     the Offer.
 
          2. The Offer is being made for all Shares.
 
          3. The Offer is conditioned upon, among other things, Shares
     representing not less than 90% of the outstanding Shares on a Fully Diluted
     Basis (as defined in the Offer to Purchase) being validly tendered and not
     withdrawn prior to the expiration of the Offer (the "Minimum Share
     Condition"). The Offer is
<PAGE>   2
 
     also subject to other terms and conditions contained in the Offer to
     Purchase. See the Introduction and Sections 1, 14 and 15 of the Offer to
     Purchase.
 
          4. Tendering stockholders will not be obligated to pay brokerage fees
     or commissions or, except as otherwise provided in Instruction 6 of the
     Letter of Transmittal, stock transfer taxes on the purchase of Shares by
     the Purchaser pursuant to the Offer.
 
          5. The Offer and withdrawal rights will expire at 12:00 midnight, New
     York City time, on Monday, August 5, 1996, unless the Offer is extended.
 
          6. Payment for Shares purchased pursuant to the Offer will in all
     cases be made only after timely receipt by The First National Bank of
     Boston (the "Depositary") of (a) Share Certificates for such Shares or
     timely confirmation of the book-entry transfer of such Shares into the
     account maintained by the Depositary at The Depository Trust Company,
     Midwest Securities Trust Company or Philadelphia Depository Trust Company
     (collectively, the "Book-Entry Transfer Facilities"), pursuant to the
     procedures set forth in Section 3 of the Offer to Purchase, (b) 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 (c) any other documents required by the Letter of
     Transmittal. Accordingly, payment may not be made to all tendering
     stockholders at the same time depending upon when Share Certificates or
     confirmations of book-entry transfer of such Shares into the Depositary's
     account at a Book-Entry Transfer Facility are actually received by the
     Depositary.
 
     If you wish to have us tender any or all of the Shares held by us for your
account, please so instruct us by completing, executing, detaching and returning
to us the instruction form set forth below. If you authorize the tender of your
Shares, all such Shares will be tendered unless otherwise specified below. An
envelope to return your instructions to us is enclosed. Your instructions should
be forwarded to us in ample time to permit us to submit a tender on your behalf
prior to the expiration of the Offer.
 
     The Offer is not being made to (nor will tenders be accepted from or on
behalf of) holders of Shares residing in any jurisdiction in which the making of
the Offer or the acceptance thereof would not be in compliance with the
securities, blue sky or other laws of such jurisdiction. However, Purchaser may,
in its discretion, take such action as it may deem necessary to make the Offer
in any jurisdiction and extend the Offer to holders of Shares in such
jurisdiction.
 
     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 is being made on
behalf of Purchaser by one or more registered brokers or dealers that are
licensed under the laws of such jurisdiction.
 
                                        2
<PAGE>   3
 
               INSTRUCTIONS WITH RESPECT TO THE OFFER TO PURCHASE
 
                      FOR CASH ALL SHARES OF COMMON STOCK
 
                                       OF
 
                                  AMBAR, INC.
 
     The undersigned acknowledge(s) receipt of your letter and the enclosed
Offer to Purchase, dated July 9, 1996 (the "Offer to Purchase"), and the related
Letter of Transmittal (which together constitute the "Offer") in connection with
the offer by AI Acquisitions Corp., a Delaware corporation ("Purchaser") formed
by The Beacon Group, a New York general partnership, to purchase all outstanding
shares of common stock, par value $.01 per share (the "Shares"), of AMBAR, Inc.,
a Delaware corporation (the "Company"), at a purchase price of $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 Purchase.
 
     This will instruct you to tender to Purchaser the number of Shares
indicated below (or if no number is indicated below, all Shares), which are held
by you for the account of the undersigned, upon the terms and subject to the
conditions set forth in the Offer.
 
<TABLE>
<S>                                             <C>
Number of Shares:                               Name(s) of Record Holder(s):
Certificate Nos. (if available):                (PLEASE TYPE OR PRINT)
Check ONE box if Shares will be tendered by
book-entry transfer:                            Address(es):
/ / The Depository Trust Company
/ / Midwest Securities Trust Company
/ / Philadelphia Depository Trust Company                     (INCLUDE ZIP CODE)
Account Number:                                 Area Code and Tel. No.:
                                                Signature(s):
                                                Dated:
</TABLE>
