
<PAGE>   1
 
                         NOTICE OF GUARANTEED DELIVERY
 
                                      FOR
 
                        TENDER OF SHARES OF COMMON STOCK
 
                                       OF
 
                                  AMBAR, INC.
 
     This Notice of Guaranteed Delivery or one substantially equivalent hereto
must be used to accept the Offer (as defined below) if certificates representing
shares of common stock, par value $.01 per share (the "Shares"), of AMBAR, Inc.,
a Delaware corporation (the "Company"), are not immediately available or time
will not permit all required documents to reach The First National Bank of
Boston (the "Depositary") on or prior to the Expiration Date (as defined in the
Offer to Purchase), or the procedures for delivery by book-entry transfer cannot
be completed on a timely basis. This Notice of Guaranteed Delivery may be
delivered by hand or sent by facsimile transmission or mail to the Depositary.
See Section 3 of the Offer to Purchase.
 
                        THE DEPOSITARY FOR THE OFFER IS:
 
                       THE FIRST NATIONAL BANK OF BOSTON
 
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           By Mail:              By Facsimile Transmission:              By Hand:
 Shareholder Services Division         (617) 575-2232            BancBoston Trust Company
         P.O. Box 1889                 (617) 575-2233                   of New York
      Mail Stop 45-02-53         (For Eligible Institutions      55 Broadway, Third Floor
  Boston, Massachusetts 02105               Only)                   New York, New York
        (617) 575-3120
                               Confirm Facsimile by Telephone:      By Overnight Courier:
                                       (617) 575-3120           The First National Bank of
                                   (For Confirmation Only)                Boston
                                                               Shareholder Services Division
                                                                     150 Royall Street
                                                                    Mail Stop: 45-02-53
                                                                Canton, Massachusetts 02021
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     DELIVERY OF THIS NOTICE OF GUARANTEED DELIVERY TO AN ADDRESS OTHER THAN AS
SET FORTH ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA A FACSIMILE TRANSMISSION TO
A NUMBER OTHER THAN AS SET FORTH ABOVE WILL NOT CONSTITUTE A VALID DELIVERY.
 
     THIS NOTICE OF GUARANTEED DELIVERY IS NOT TO BE USED TO GUARANTEE
SIGNATURES. IF A SIGNATURE ON A LETTER OF TRANSMITTAL IS REQUIRED TO BE
GUARANTEED BY AN "ELIGIBLE INSTITUTION" UNDER THE INSTRUCTIONS THERETO, SUCH
SIGNATURE GUARANTEE MUST APPEAR IN THE APPLICABLE SPACE PROVIDED IN THE
SIGNATURE BOX ON THE LETTER OF TRANSMITTAL.
<PAGE>   2
 
Ladies and Gentlemen:
 
     The undersigned hereby tenders to AI Acquisitions Corp., a Delaware
corporation ("Purchaser"), upon the terms and subject to the conditions set
forth in the Offer to Purchase, dated July 9, 1996 (the "Offer to Purchase"),
and in the related Letter of Transmittal (which together constitute the
"Offer"), receipt of each of which is hereby acknowledged, the number of Shares
indicated below pursuant to the guaranteed delivery procedures set forth in
Section 3 of the Offer to Purchase.
 
Number of Shares:             Shares
 
Certificate No(s). (if available):
 
If Share(s) will be tendered by book-entry transfer, check one box.
 
/ / The Depository Trust Company
/ / Midwest Securities Trust Company
/ / Philadelphia Depository Trust Company
Name(s) of Record Holder(s):
 
Address(es):
 
Area Code and Telephone Number(s):
 
Signature(s):
 
                     THE GUARANTEE BELOW MUST BE COMPLETED
                                   GUARANTEE
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)
 
     The undersigned, a firm that is a bank, broker, dealer, credit union,
savings association or other entity which is a member in good standing of the
Securities Transfer Agents Medallion Program, hereby (1) represents that the
tender of Shares effected hereby complies with Rule 14e-4 under the Securities
Exchange Act of 1934, as amended, and (2) guarantees to deliver to the
Depositary, at one of its addresses set forth above, the certificates
representing all tendered Shares, in proper form for transfer, or a Book-Entry
Confirmation (as defined in the Offer to Purchase), together with a properly
completed and duly executed Letter of Transmittal (or facsimile thereof), with
any required signature guarantees, or, in the case of book-entry transfer of
Shares, an Agent's Message (as defined in the Offer to Purchase), and any other
documents required by the Letter of Transmittal within three NASDAQ National
Market trading days after the date of execution of this Notice of Guaranteed
Delivery.
 
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- --------------------------------------------     --------------------------------------------
Name of Firm                                     (Authorized Signature)
- --------------------------------------------     --------------------------------------------
Address                                          Title
                                                 Name:
                                                 (Please type or print)
- --------------------------------------------
                                                 Date:
- --------------------------------------------
Area Code and Telephone Number
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        NOTE: DO NOT SEND SHARE CERTIFICATES FOR SHARES WITH THIS NOTICE
              OF GUARANTEED DELIVERY. SHARE CERTIFICATES SHOULD BE
                     SENT WITH YOUR LETTER OF TRANSMITTAL.
