
<PAGE>   1

                                                        EXHIBIT (a)(10)

                           (AMBAR LETTERHEAD)



 
Dear _________:

   
        AMBAR, Inc. (the "Company") has entered an Agreement and Plan of Merger
(the "Merger Agreement") with AI Partners L.P. and AI Acquisitions Corp.
("Purchaser") pursuant to which the Purchaser has commenced a tender offer (the
"Offer") to purchase outstanding shares of Company common stock (the "Common
Stock") for $18 per share in cash. If the Offer is successfully completed, it is
anticipated that the Company will thereafter be merged into the Purchaser (the
"Merger") and any Company stockholders who have not tendered will also receive
$18 per share in cash for their stock. The Merger Agreement, the Merger, the
Offer and the Board of Directors' recommendation with respect to the Offer are
discussed further in the Offer to Purchase and the Schedule 14D-9
Solicitation/Recommendation Statement that is enclosed with this letter.
    

       You have been awarded options under either the Company's 1991
Employees' Incentive Compensation Program or the 1994 Non-employee Directors'
Incentive Compensation Program (collectively, the "Stock Option Plans"). Under
the terms of both Stock Option Plans, your options become exercisable upon a
change of control of the Company. It is anticipated that following the closing
of the Offer, the Purchaser will exercise its right under the Merger Agreement
to appoint a majority of the Company's Board of Directors, an event which would
constitute a change of control under the Stock Option Plans.

   
        You may exercise your options immediately upon occurrence of a change
of control by completing the Notice of Exercise attached hereto as Exhibit B
and returning it to the Company, along with a check payable to the Company in
an amount equal to the number of options exercised multiplied by the exercise
price for such options as shown on Exhibit A attached hereto. In such case,
the shares that you would receive upon exercise of your options would be
converted into a right to receive a cash payment in an amount equal to $18.00
per share upon consummation of the Merger. However, you may prefer, and we
recommend, that you take advantage of the arrangement that is described in the
next paragraph.
    

        The Company and the Purchaser have made arrangements for you, subject
to and upon consummation of the Merger, to receive a cash payment in an amount
equal to the difference between the $18 per share price to be paid in
connection with the Merger and the exercise price for the options as listed on
Exhibit A attached hereto, less applicable withholding taxes. Under this
arrangement, you will not be required to exercise your options or pay the
corresponding exercise price. In order to elect this alternative, you must 
complete the Notice of Exercise attached hereto as Exhibit B and return it to
the Company. You may expect payment of the amounts due you within _____ days
of the consummation of the Merger.

        Completion of the Notice of Exercise and acceptance of shares of Common
Stock or of cash in an amount equal to the difference between the exercise
price and $18 per share, less applicable withholding taxes, will constitute
your acknowledgment that the Company's obligations with respect to the Stock
Options have been fully satisfied and discharged.

        If you have any questions regarding your options, please contact Barry
N. Huntsman at 318-237-5300.

                                      Sincerely,


                                      Randolph M. Moity, Sr.
                                      Chairman of the Board, President
                                      And Chief Executive Officer
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                                                                  EXHIBIT B
   
                            NOTICE OF EXERCISE OF
                  STOCK OPTION GRANTED UNDER THE AMBAR, INC.
                1991 EMPLOYEES' INCENTIVE COMPENSATION PROGRAM
                     OR THE 1994 NON-EMPLOYEE DIRECTORS'
                        INCENTIVE COMPENSATION PROGRAM
    



AMBAR, Inc.
221 Rue de Jean
Lafayette, Louisiana 70505

    Attention: Barry N. Huntsman


Gentlemen:

   Notice is hereby given of the undersigned's exercise of Options to purchase
______ shares of common stock of AMBAR, Inc. (the "Company") granted to the
undersigned under the terms of either the 1991 Employees' Incentive
Compensation Program or the 1994 Non-employee Directors' Incentive Compensation
Program (the "Stock Plans"). In connection with such exercise I select the
following option:

    __  The undersigned elects to exercise his options and receive shares of 
        Common Stock of the Company in exchange therefor. Enclosed is a check
        in the amount of $______ representing the exercise price of the shares 
        to be purchased.

   
    __  The undersigned elects to receive a cash payment in an amount equal to
        the difference between the exercise price for each option and the $18.00
        per share to be paid to Company Stockholders in connection with the 
        merger of the Company and AI Acquisitions Corp.
    


    The undersigned recognizes that he/she is required to satisfy the
applicable federal and state withholding taxes related to the exercise of these
options. With respect thereto, the undersigned has elected, in accordance with
the terms of the Stock Plans, to have the Company withhold from the number of
shares or the amount of cash the undersigned would otherwise receive in
connection with this option exercise, shares of Common Stock or cash having a 
value equal to the amount required to satisfy such taxes.

    The undersigned hereby acknowledges by his/her signature below that receipt
of cash or shares of common stock in connection with this Notice of Exercise of
Stock Option constitutes full satisfaction and discharge of the Company's
obligations with respect to such options.


                                        Sincerely,


                                        -----------------------------------
                                        Optionee
                                        Date:______________________________










