AMENDMENT TO THE SHARE PURCHASE AGREEMENT OF 27 JUNE 1997

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                                                                  EXHIBIT 2.2(a)
                                                                               

                    AMENDMENT TO THE SHARE PURCHASE AGREEMENT
                                 OF 27 JUNE 1997



BETWEEN THE UNDERSIGNED:

1.       THE COMPANY LABORATOIRES PEROUSE S.A.,

         Societe Anonyme with a capital of FRF 8,028,000, whose registered
         office is at Zone d'Activites d'OUTREVILLE - BORNEL (Oise), re gistered
         in the registry of commerce of BEAUVAIS under number B 317.883.999,

         Represented by Xx Xxxx-Xxxx XXXXXX, acting as the Administration and
         Finance Director of the said company and having the power to sign the
         amendment following a meeting of the Board of Directors of 20 June
         1997.

                  HEREAFTER, "LABORATOIRES PEROUSE" OR "THE TRANSFEROR"

AND

2.       THE COMPANY XXXXXXXX MICRO SCIENCE N.V.,

         Societe Anonyme whose registered office is at Atealaan 4 - 2200
         HERENTALS, registered in the registry of commerce of TURNHOUT under
         number 55083,

         Represented by Xx Xxxx XXXXXX, acting as the managing director of said
         company.

                  HEREAFTER, "THE BUYER"

Whereas Article 3(d) and (f) of the Share Purchase Agreement of June 27, 1997
provide for the acceptance by the Buyer by July 9, 1997 of the Guaranty Contract
with the representations of guarantees supplied by the Transferor, as well as
the delivery by the Transferor of the bank guaranty at first demand in the
amount of one million French francs and of the schedules to the Contract;

Whereas the parties have not been able to agree on the date in the text of the
guaranty covenant:

IT IS AGREED AS FOLLOWS:...

The parties agree to modify the date of July 9, 1997 which is mentioned in
Articles 3(d) and 3(f) to the date of July 31, 1997; it being understood that
the delay of 120 days foreseen by Article 3, starting from June 26, 1997 remains
unchanged.

All other provisions of the Share Puchase Agreement of June 26, 1997 remain
unchanged.



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                                                 Done in two originals
                                                    on 9 July 0000






/x/  Xxxx-Xxxxxx XXXXXX                          /s/ Xxxx Xxxxxx
Xx Xxxx-Xxxxxx XXXXXX                            Xx. Xxxx XXXXXX
Acting in the name and                           Acting in the name and
for the account of                               for the account of
"LABORATOIRES PEROUSE"                           "XXXXXXXX MICRO SCIENCE N.V."