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                                                                    EXHIBIT 4.01


                       FIRST AMENDMENT TO CREDIT AGREEMENT

Harris Trust and Savings Bank
Chicago, Illinois

Gentlemen:

         Reference is hereby made to that certain Credit Agreement (the "Credit
Agreement"), dated as of September 23, 1997, by and among Comshare, Incorporated
(the "Company") and Comshare Limited (the "Borrowing Subsidiary") (together the
"Borrowers") and Harris Trust and Savings Bank (the "Bank"). All capitalized
terms used herein without definition shall have the same meanings herein as such
terms have in the Credit Agreement.

         The Borrowers have requested that the Bank amend certain provisions of
the Credit Agreement and the Bank will do so under the terms and conditions set
forth in this Amendment.

1.       AMENDMENTS.

         Upon your acceptance hereof in the space provided for that purpose
         below, the Credit Agreement shall be and is hereby amended as follows:

         (a)  The portion of the definition of "Borrowing Base" appearing before
              the term "provided" in Section 5 of the Credit Agreement shall be
              amended and as so amended shall be restated to read as follows:

              "Borrowing Base" means, as of any time it is to be determined, the
              sum of:

              (a)  80% of the then outstanding unpaid amount of Eligible
                   Accounts other than Software Maintenance Receivables; plus

              (b)  70% of the then outstanding unpaid amount of Eligible
                   Accounts consisting of Software maintenance Receivables; plus

              (c)  the lesser of $6,000,000 or 50% of the cash on hand of the
                   Company and its Subsidiaries then on deposit in accounts
                   maintained at the Bank;"

         (b)  The definition of "Borrowing Base" appearing in Section 5 of the
              Credit Agreement shall be further amended by deleting (b)(iii) and
              (iv) appearing therein and inserting the following in their stead:

              "(iii) the Borrowing Base attributable to Comshare Canada shall
              not exceed $950,000, (iv) no Borrowing ] Base shall be
              attributable to the Borrowing Subsidiary except during the period
              when that certain Debt Subordination Agreement dated as of
              September 23, 1997 between the Company and its Affiliates (the
              "Debt Subordination Agreement") is in full force and effect
              provided that no more than $7,287,000 of the Borrowing Base of the
              Borrowing Subsidiary shall be used to support borrowings by the
              Company (it being understood and agreed that no such limitation
              shall apply to the Borrowing Base of the Borrowing Subsidiary used
              to support borrowings by the Borrowing Subsidiary itself) and"

         (c)  Section 8.7 of the Credit Agreement shall be amended by deleting
              the amount "$28,000,000" appearing in the fifth line thereof and
              inserting the amount "$18,000,000" in its stead.

         (d)  Section 8.14 of the Credit Agreement shall be amended by inserting
              after subsection (b) the following phrase as subsection (c):

                   "the Company's expenditure of up to $10,000,000 during its 
              fiscal year ending on or about June 30, 1999 for the redemption of
              certain of its capital stock"



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         (e)  The Company represents and warrants to the Bank that Comshare U.K.
              has merged with and into the Borrowing Subsidiary, with the
              Borrowing Subsidiary being the corporation surviving such merger.
              Accordingly, (x) the references to Comshare UK in Section 5 and
              7.2 and Schedule 6.2 of the Credit Agreement shall be deleted and
              (y) any other references to Comshare UK in the Credit Agreement
              shall be deemed references to the Borrowing Subsidiary.

2.       CONDITIONS PRECEDENT.

The effectiveness of this Amendment is subject to the satisfaction of all of the
following conditions precedent:

         (a)  The Borrowers and the Bank shall have executed and delivered this
              Amendment.

         (b)  Legal matters incident to the execution and delivery of this
              Amendment shall be satisfactory to the Bank and its counsel.

3.       MISCELLANEOUS

         (a)  Except as specifically amended herein, the Credit Agreement shall
              continue in full force and effect in accordance with its original
              terms. Reference to this Specific Amendment need not be made in
              any document, letter, certificate, the Credit Agreement or any
              communication issued or made pursuant to or with respect to the
              Credit Agreement, any reference therein being sufficient to refer
              to the Credit Agreement as amended hereby.

         b)   This Amendment may be executed in any number of counterparts, and
              by the different parties on different counterparts, all of which
              taken together shall constitute one and the same agreement. Any of
              the parties hereto may execute this Amendment by signing any such
              counterpart and each of such counterparts shall for all purposes
              be deemed to be an original. This Amendment shall be governed by
              and construed in accordance with the laws of the State of
              Illinois.

Dated as of this 30th day of September, 1998.

                              COMSHARE, INCORPORATED


                              By        \s\ Kathryn Jehle                       
                                    -----------------------------------------
                              Title:    Senior Vice President and CFO           
                                    -----------------------------------------

                              COMSHARE LIMITED

                              By        \s\ Kathryn Jehle                       
                                    -----------------------------------------
                              Title:    Director                                
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Accepted and agreed to as of the date last above written.

                              HARRIS TRUST AND SAVINGS BANK

                              By         \s\ Kirby M. Law                       
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                                         Its Vice President