LOAN AGREEMENT

LOAN AGREEMENT,  dated as of June 30, 1998 between Huls  Corporation  located at
13801  Riverport  Drive,  Maryland  Heights,   Missouri/USA,   ("HC")  and  MEMC
Electronic Materials, Inc., located at 501 Pearl Drive, O'Fallon,  Missouri/USA,
("MEMC").

MEMC desires to borrow until September 30, 1998 an original principal amount not
to exceed  $50,000,000.00  and HC is willing,  subject to and upon the terms and
conditions herein set forth, to make such a loan to MEMC.

NOW THEREFORE IT IS AGREED:

1.   Principal and Value:  From time to time,  beginning  July 1, 1998, HC shall
     lend to MEMC and MEMC shall  borrow from HC an amount to be  designated  by
     MEMC,  not to exceed  $50,000,000.00  outstanding at any one time. The loan
     shall  be  evidenced  by a  promissory  note in  substantially  the form of
     Exhibit "A" attached hereto. All loans and repayments shall be made by MEMC
     by  drawing  funds in  multiples  of  $5,000,000  from an MEMC  account  at
     Citibank  N.A.,  New York,  New York that  will  zero  balance  with the HC
     account   at   Citibank   N.A.,   New   York  ,  New  York   (Account   No.
     4070-0001)("designated  account").  MEMC shall notify HC of borrowing[s] by
     10 am Central time on the third  business day prior to the day the money is
     to be borrowed.

2.   Term and Maturity:  The principal amount of the loan  outstanding  together
     with  any  interest  due  and  outstanding  shall  be paid by MEMC to HC on
     September  30,  1998,  or at such later date as may be  mutually  agreed in
     writing by the  parties.  MEMC shall not be  entitled  to repay the loan[s]
     before maturity without the prior written consent of HC.

3.   Interest Rates: Interest shall be calculated daily at 7.22%, beginning with
     the date of  borrowing  and shall be  calculated  based upon a 365/360  day
     year.

4.   Payment of Interest:  Payments of interest  shall be made by wire transfer,
     or other method of same day  settlement,  only on banking  days,  not later
     than 10:00 a.m. Central time, to the account of HC, with Citibank N.A., New
     York, New York,  (Account No.  4070-0001) or to such other account of HC as
     it may designate. Interest will be payable monthly, on the last banking day
     of each month.

5.   PENALTIES:  If MEMC shall borrow an amount different than which it notifies
     HC pursuant to paragraph 1, MEMC shall pay to HC a penalty equal to the .5%
     of the amount of the  understatement  divided by 360. If MEMC shall draw an
     amount in excess of $50,000,000,  MEMC shall pay HC a penalty equal to 3.0%
     of the excess amount  multiplied by the number of days outstanding  divided
     by 360.  All  penalties  shall  be in  addition  to  interest  computed  in
     accordance with other provisions of this agreement.

6.   Liens,  etc. On and after the date of this Loan Agreement  until  September
     30, 1998 or such later date as any loan hereunder shall remain unpaid, MEMC
     will not, unless HC shall otherwise consent in writing, create or suffer to
     exist, any lien,  security interest or other charge or encumbrance,  or any
     other type of preferential arrangement,  upon or with respect to any of its
     properties, whether now owned or hereafter acquired, or assign any right to
     receive  income,  in each  case to secure  any debt  owed to any  person or
     entity, other than:

          (a) purchase money liens or purchase money security  interests upon or
          in any  property  acquired or held by MEMC in the  ordinary  course of
          business to secure the  purchase  price of such  property or to secure
          indebtedness   incurred  solely  for  the  purpose  of  financing  the
          acquisition of such property;

          (b) liens or security  interests existing on such property at the time
          of its  acquisition  (other  than any such lien or  security  interest
          created in contemplation of such acquisition);

          (c) liens for taxes,  assessments and government  charges or levies to
          the extent not yet due or to the extent  such  taxes,  assessments  or
          government  charges or levies are being contested in good faith and by
          proper  proceedings  and as to which  appropriate  reserves  are being
          maintained,  unless and until any lien resulting therefrom attaches to
          MEMC's property and becomes enforceable against its other creditors;

          (d)  liens  imposed  by  law,  such  as   materialmen's,   mechanics',
          carriers',  workmens'  and  repairmen's  liens and other similar liens
          arising in the ordinary course of business  securing  obligations that
          are not overdue for a period of more than 30 days;

          (e)  pledges  or  deposits  to  secure   obligations   under  workers'
          compensation  laws or  similar  legislation  or to  secure  public  or
          statutory obligations;

          (f) easements,  rights of way and other  encumbrances on title to real
          property that do not render title to the property  encumbered  thereby
          unmarketable or materially  adversely  affect the use of such property
          for its present purposes; and

          (g) liens incurred or deposits made in the ordinary course of business
          to secure the performance of letters of credit,  bids, tenders,  sales
          contracts,  leases,  surety,  appeal and  performance  bonds and other
          similar  obligations  not incurred in connection with the borrowing of
          money.

7.   Copies: This agreement is made up of two (2) identical copies, of which one
     copy is for HC and the other for MEMC.

8.   Applicable   Law:  This  agreement   shall  be  governed  by  the  laws  of
     Missouri/U.S.A.

9.   Notice: All notices to HC shall be sent by telefax to:

          Mitchell Solomowitz
          Telefax: (314)-298-4185

          with a copy to John Schaffner @ (314) 298 - 4185

          The original should be sent to Mitchell Solomowitz

      All notices to MEMC shall be sent by telefax;

          Kenneth Young
          Telefax:          (314) 279 - 5158

10.  Assignment/Subrogation:

     MEMC shall not transfer or assign any or all of its rights and  obligations
     hereunder  without the prior written consent of HC. HC may at any time upon
     at least  three days'  prior  written  notice to MEMC assign its rights and
     obligations hereunder, in full or in part, in which case the assignee shall
     be subrogated to the rights of HC to the extent of such assignment

Agreed upon as of this 30th day of June, 1998.

Maryland Heights, Missouri                       O'Fallon, Missouri
Huls Corporation                                 MEMC Electronic Materials, Inc.

By: /s/ H. J. Biangardi                         By: /s/ Kenneth L. Young
   _______________________                         _______________________
Name:  H. J. Biangardi                             Kenneth L. Young
Title: President & CEO                             Treasurer


By: /s/ Mitchell Solomowitz
    _______________________
    Mitchell Solomowitz
    Treasurer



                                   EXHIBIT "A"

                                 PROMISSORY NOTE

U.S. $50,000,000.00                                          O'Fallon, Missouri,
                                                                   June 30, 1998

MEMC Electronic Materials, Inc. ("MEMC"), for value received, hereby promises to
pay to the order of HULS Corporation ("HC") in lawful money of the United States
of America (in freely  transferable  U.S.  dollars  and in same day  funds),  in
accordance  with the method of payment  specified in that certain Loan Agreement
dated as of June 30,  1998,  between  HC and MEMC  ("the  Agreement"),  the full
principal amount outstanding (as specified in paragraph 1 of the Agreement), not
to  exceed  $50,000,000.00,  which  amount  shall be  payable  at such  times as
provided in the Agreement.

MEMC promises also to pay interest on the unpaid principal amount hereof in like
money and in like manner at the rates which shall be  determined  in  accordance
with the provisions of the  Agreement,  said interest to be payable at the times
provided for in the Agreement.  This Note is referred to in the Agreement and is
entitled to the benefits  thereof and the security  contemplated  thereby.  This
Note  evidences  a loan  made by HC,  during  such  time as such  loan is  being
maintained. This Note is subject to prepayment as specified in the Agreement. In
case MEMC defaults on the loan, the principal and accrued  interest on this Note
may be declared to be due and payable in the manner and with the effect provided
in the Agreement.  It is contemplated that by reason of payment hereon there may
be times when no  indebtedness  is owing  hereunder;  but  notwithstanding  such
occurrences,  this Note shall remain valid and shall be in full force and effect
as to amounts borrowed under the Agreement subsequent to each such occurrence.

MEMC  hereby  waives  presentment,  demand,  protest  or  notice  of any kind in
connection with this Note.

This Note shall be governed and construed and interpreted in accordance with the
laws of the State of Missouri.

                                               MEMC Electronic Materials, Inc.

                                               By: /s/ Kenneth L. Young
                                                   _____________________________
                                                   Kenneth L. Young
                                                   Treasurer