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                                                                 EXHIBIT 10-G(1)
                     SECOND AMENDMENT TO TECHNICAL AGREEMENT

This Second Amendment to Technical  Agreement - Silicon Wafer Manufacturing (the
"Second  Amendment")  is effective as of September 30, 1998, by and between MEMC
ELECTRONIC  MATERIALS,  INC., a Delaware  corporation  ("MEMC"),  and POSCO HULS
COMPANY LIMITED, a Korea  corporation  ("PHC").  All terms used herein,  unless
otherwise  defined,  shall  have  the  same  meanings  ascribed  to  them in the
Agreement (as defined below).

                                    RECITALS

A.        MEMC  and  PHC  made  and   entered   into  that   certain   Technical
          Agreement  --  Silicon  Wafer  Manufacturing  as of December 19,  1990
          and  that  certain  Amendment  to Technical Agreement effective as  of
          January       1,       1995       (as       so      amended,       the
          "Agreement").

B.       Section  14.03 of the  Agreement  provides that it will expire five (5)
         years from the Date of First Commercial Production (September 30, 1993)
         or on September 30, 1998 unless the parties have renegotiated the terms
         thereof.

C.       The parties are in the process of renegotiating in good faith the terms
         of the  Agreement,  and wish to extend the term  thereof  for three (3)
         months in order to allow them to complete their negotiations.

NOW, THEREFORE, pursuant to Section 17.03 of the Agreement, the parties agree as
follows:

1.       Extension of Term.

          a.   Section  14.03 of the  Agreement  shall be amended to read in its
               entirety as follows:

               "It  is   understood   that,  in  the  case  of  failure  of  the
               negotiations under Section 3.5 of this Agreement,  this Agreement
               shall expire on December 31, 1998, and such expiration  shall not
               act to terminate  rights and licenses already granted pursuant to
               this Agreement, provided, however, such rights and licenses shall
               be non-exclusive."

          b.   The  Agreement  is also amended so that the all of the rights and
               obligations  of the parties which expire under the Agreement five
               (5) years from the Date of First Commercial Production, including
               the obligation of the parties to supply technical information and
               continuing  know-how  to each  other  under  Article  III and the
               obligation of PHC to pay MEMC a running  royalty under Article V,
               shall continue through December 31, 1998.

          c.   The parties will  endeavor to complete  another  amendment to the
               agreement by December 31, 1998; such  additional  agreement shall
               be  retroactively  effective as of October 1, 1998  regardless of
               the date of execution.  The Second Amendment shall  automatically
               expire upon execution of the additional agreement.

2.       Effect

         This Second  Amendment shall become effective on September 30, 1998 and
         shall  supercede any provisions of the Agreement  which are in conflict
         with this Second Amendment. All other provisions of the Agreement shall
         remain effective and binding.

IN WITNESS WHEREOF, the parties have executed this Second Amendment as follows:

MEMC ELECTRONIC MATERIALS, INC.                 POSCO HULS COMPANY, LIMITED


By: /s/ Paul V. Pastorek                         By: /s/ Sang Bok Hong
   --------------------------------                 ----------------------------
Title:  Corporate Vice President                 Title:  President
Date:  September 30, 1998                        Date:  September 30, 1998