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                                                                    EXHIBIT 4.26

                                                               November 12, 1999

Illinois Superconductor Corporation
451 Kingston Court
Mount Prospect, Illinois 60056

Ladies and Gentlemen:

         This letter amends the letter agreement ("Agreement") captioned
"Additional Investment" by and among Elliott Associates, L.P., Westgate
International, L.P., and Alexander Finance, L.P. ("Investors") and Illinois
Superconductor Corporation ("Company"), dated November 5, 1999, by deleting the
last two sentences of Section 12 of the Agreement and replacing those sentences
with the following:

         Notwithstanding anything to the contrary contained herein or in the
         Notes and Warrants, unless and until the foregoing Charter Amendment is
         effected, and except with respect to determining the redemption rights
         referred to above, the Notes and Warrants held by the undersigned on
         the date of the Agreement after giving effect thereto and regardless of
         whether such Notes and Warrants are transferred at any time (such Notes
         and Warrants are the "Investor Notes and Warrants") shall represent a
         right in the aggregate, allocated pro rata among them, to acquire
         (including with respect to in-kind interest payments paid and to be
         paid) that number of shares (but not more than that number of shares)
         of Common Stock equal to the number of shares of Common Stock currently
         authorized by the Company's Certificate of Incorporation reduced by the
         sum of (i) the number of shares and shares subject to options
         outstanding on the date hereof, (ii) the number of shares subject to
         additional options granted under the Illinois Superconductor
         Corporation 1993 Stock Option Plan, as amended through June, 1999
         ("Plan"), (iii) the


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         number of shares subject to any options granted outside the Plan with
         the written consent of the undersigned, and (iv) the number of shares
         (including with respect to in-kind interest payments paid and to be
         paid through November 5, 2000) that the Notes and Warrants other than
         the Investor Notes and Warrants carry the right to acquire.

         This letter amending the Agreement may be executed in multiple
counterparts which together shall constitute the amendment to the Agreement. As
modified herein, the documents relating to the Notes and Warrants remain in full
force and effect.

                                      Sincerely,

                                      ELLIOTT ASSOCIATES, L.P.



                                      By: /s/ PAUL SINGER
                                      -------------------

                                      WESTGATE INTERNATIONAL, L.P.
                                          By:  Martley International, Inc.
                                                Attorney-in-Fact



                                                By: /s/ PAUL SINGER
                                                    -----------------------

                                      ALEXANDER FINANCE, L.P.



                                          By: /s/ BRADFORD T. WHITMORE
                                              -----------------------------


AGREED TO AND ACCEPTED:

ILLINOIS SUPERCONDUCTOR CORPORATION



By: /s/ CYNTHIA QUIGLEY
    ----------------------------------




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