AGZ HOLDING                                          EXHIBIT 10.15
Mr. Francois VARAGNE
                                                     22 rue Octave Feuillet

                                                     75016 PARIS

                                                     May 15, 2002

Subject: Contractual revocation indemnity

Sir,

Following the approval granted by the Board of Directors of AGZ Holding on May
14, 2002, we hereby undertake to pay you a contractual indemnity in the event of
revocation of your functions in Antargaz under the conditions specified below.

In the event of revocation of your functions as Chairman of the Board of
Directors of Antargaz, AGZ Holding will pay you a revocation indemnity under the
following conditions:

      -     The indemnity will be paid to you in the event of revocation of your
            functions as Chairman of the Board of Directors and General Director
            of Antargaz.

      -     The revocation must not be based on severe or gross negligence in
            the performance of your functions as Chairman of the Board of
            Directors and General Director of Antargaz.

      -     The payment of the revocation indemnity is subject to the signing of
            a settlement which, in consideration of such payment, would include
            a complete and final waiver on your part to contest in any manner
            whatsoever the execution and the termination of your mandate as
            Chairman of the Board of Directors and General Director of Antargaz
            and, if applicable, your mandate as Deputy General Director of AGZ
            Holding, within a term of 15 calendar days from the effective date
            of your revocation. If, in light of the procedure followed and the
            reasons invoked to support your revocation, you consider that it is
            not in your interest to sign a settlement under the above
            conditions, AGZ Holding will be released from the commitment assumed
            hereunder and you will not be able to claim any payment based on it.

      -     The revocation indemnity will be in the amount of one (1) year of
            compensation paid by Antargaz in your capacity of Chairman of the
            Board of Directors of said company, based on twelve (12) full months
            of compensation prior to the effective date of your revocation.

      -     Sincerely,

                                              [signature]
                                              Herve COUFFIN
                                              Chairman of the Board of Directors