<PAGE>   1


                                                                EXHIBIT 10.05



                              DATED 30TH JULY 1997




     (1) COMSHARE LIMITED

         and

     (2) DAVID HUNTER MACKENZIE
         DION O'LEARY
         KATHRYN JEHLE
         NICHOLAS PAUL SEATON BRAY
         MARY ANN MOORE



                     _____________________________________

                               DEED OF VARIATION
                                - RELATING TO -
                          THE COMSHARE RETIREMENT AND
                              DEATH BENEFITS PLAN
                     _____________________________________



<PAGE>   2

THIS DEED OF VARIATION is made the 30th day of July 1997 BETWEEN COMSHARE
LIMITED of 22 Chelsea Manor Street London SW3 5RL ("the Principal Employer")
of the one part and DAVID HUNTER MACKENZIE of 74 Thetford Road  New Malden 
Surrey DION O'LEARY of 21 West Park Road  Kew Richmond London TW9 4DB KATHRYN
JEHLE of 2455 Adare Ann Abor 48104  Michigan USA NICHOLAS PAUL SEATON BRAY of
14 Shelly Road High Wycombe Buckinghamshire HP11 2UP and MARY ANN MOORE 
20 Lime Avenue Groby Leicester LE2 OEN ("the Trustees") of the other part
        
WHEREAS:-

(A)  This Deed is supplemental inter alia to

     (i)   an Interim Trust Deed made 25th August 1971 between the
           Principal Employer of the first part and the then trustees of the
           second part whereby the Principal Employer established the Comshare
           Retirement and Death Benefits Plan ("the Plan")

     (ii)  a Definitive Trust Deed made 28th April 1978 between the
           Principal Employer of the first part and the then trustees of the
           second part ("the Definitive Deed") bringing into effect rules ("the
           Old Rules") in accordance with which the Plan was to be administered

     (iii) a Deed of Variation made 21st December 1982 between the
           Principal Employer of the first part and the then trustees of the
           other part whereby the Principal Employer and the then trustees
           amended the Definitive Deed with effect from 1st July 1981

     (iv)  a Deed of Variation made 3rd April 1990 between the Principal
           Employer of the one part and the then trustees of the other part

     (v)   a Deed of Variation made 31st May 1990 between the Principal
           Employer of the one part and the then trustees of the other part



                                      2
<PAGE>   3

      (vi)   a Deed of Variation ("the Deed of Variation") made 28th August 
             1992 between the Principal Employer of the one part and the
             then trustees of the other part bringing into effect new rules 
             ("the Rules") in accordance with which the Plan is to be 
             administered

      (vii)  a Deed of Variation dated 27th January 1993 between the
             Principal Employer of the one part and the then trustees of the
             other part

      (viii) a Deed of Retirement and Amendment dated 7th December 1994 between
             the Principal Employer of the first part the continuing trustees
             named therein of the second part and the retiring trustee named
             therein of the third part.

(B)   By Rule 23 of the Rules and Clause 5 of the Deed of Variation the
      Principal Employer and the Trustees have power subject to the limitations
      therein contained to amend or add to the Deed of Variation and the Rules
      and to substitute other rules for the Rules.

(C)   The Principal Employer and the Trustees wish to amend the Rules in the
      manner hereinafter appearing

NOW THIS DEED WITNESSES that in exercise of the powers conferred by rule 23 of
the Rules and by clause 5 of the Deed of Variation and all other relevant
powers the Principal Employer and the Trustees hereby amend the Rules as
follows; each amendment to take effect from the date shown at its head:

1.    With effect from 1 January 1991:

      (a)   The definition of "Pensionable Salary" in Rule 1 is deleted
            and replaced by the following:

            ""Pensionable Salary" means unless it is otherwise agreed by letter
            between the Member and the Principal Employer the Member's basic
            annual salary or wages, plus any shift allowance or disturbance
            allowance on the date of joining the Plan and on each subsequent
            Plan Anniversary Date, plus the annual average of any profit
            related pay, any commission received, any bonus received or




                                      3
<PAGE>   4

            due but not paid, in which case it shall be considered to have been
            paid in the year in which it was due and in the case of a Category
            3 Employee only, the notional value of any benefits in kind which
            are assessable to income tax as emoluments under Schedule E, in the
            three years up to the 30th June immediately before the Plan
            Anniversary Date on which basic salary is determined less in the
            case of a Category 1 Employee or a Category 2 Employee 1.25 times
            the annual equivalent of the lower Earnings Limit on 6th April
            immediately preceding the Plan Anniversary Date."

       (b)  paragraph (b)(ii) of Rule 9B is deleted and replaced by the
            following:

            "(ii) any benefits in excess of the benefits described
                  in (i) above will be increased by the greater of the
                  Revaluation Percentage and the increase in the Index subject
                  to a maximum rate of eight per cent compound for each year
                  between the date of leaving Employment and his date of
                  retirement but in any event the increase will be at least
                  sufficient to meet the requirements imposed by the Revaluation
                  Laws."

2.     With effect from 1st August 1992 rule 2 of the Rules is deleted and
       replaced by the following:


       "2.  JOINING THE PLAN (see also Rule 15 of the Overriding Appendix)

       Except where specific eligibility requirements are hereinafter laid down
       as applying at specified dates this Rule shall take effect from 1st 
       August 1992.

       Each Employee who is eligible to join Eligible Category I or Eligible
       Category 2 may join the Plan on the first of the month after he fulfils
       the following conditions:-





                                      4
<PAGE>   5




            (a)  he has reached age 21 but is not over age 64 (or
                 in the case of a female Employee who is eligible to join
                 Eligible Category 1 who joined Employment prior to 1st August
                 1992 she has reached age 21 but is not over age 59)

            (b)  he has completed at least 6 months' Employment.

            Except in the case of an Employee who has elected to pay Category 3
            Employee Contributions each Employee who is eligible to join
            Eligible Category 3 may join the Plan on the first of the month
            after he fulfils the following conditions:-

            (a)  he has reached age 21 but is not over age 63

            (b)  he has completed at least 6 months' Employment.

            Each Employee who is eligible to join Eligible Category 3 and who
            elects to pay Category 3 Employee Contributions may join the Plan
            on the first of the month after he fulfils the following
            conditions:-

            (a)  he has reached age 21 but is not over age 60

            (b)  he has completed at least 6 months' Employment.

      All employees of the Employers will be eligible to join the Plan for the
      benefits described in (ii) of Rule 7A provided they have not attained
      their Normal Retiring Date.

      If an Eligible Employee does not join at the first opportunity, he may
      join later only with the specific permission of the Principal Employer
      and the Trustees.  Likewise if a Member has opted out of the Plan under
      Rule 9A, he may rejoin the Plan at a later date only with the specific
      permission of the Principal Employer and the Trustees.





                                      5
<PAGE>   6


      The Principal Employer may vary the requirements of this Rule for any
      Eligible Employee or class of Eligible Employees.  It may also allow an
      employee of an Employer who is not an Eligible Employee to join the Plan
      (in which case references to "Eligible Employees" in these Rules include
      such an employee).

      Applications to join the Plan must be made in the form required by the
      Trustees.

      A director may only join the Plan if he receives remuneration from the
      Employers which he does not have to account for to another company or
      employer and which is not treated for tax purposes as receipts of a
      profession which he carries on.

      Within 13 weeks of joining or such other period as is required by law a
      Member will be given basic information about the Plan as required by the
      Disclosure Laws.

3.    With effect from 12th May 1993 the following alterations are made to rule
      9 of the Rules:

      (a)  the first paragraph of Rule 9B is deleted and replaced by the
           following:

           "A Member who ceases to be in Pensionable Employment before Normal
           Retiring Date and who satisfies the preservation requirements (see
           Rule 9D) will receive a pension for life from Normal Retiring Date
           of an amount calculated as described in Rule 5A, but, based on the
           Member's Pensionable Employment completed up to the date of leaving
           and the greater of Final Pensionable Salary and Pensionable Salary
           at that date.  However, a Class A Member who is still in Employment
           when he reaches Normal Retiring Date may not receive a pension or
           lump sum until he actually leaves Employment or reaches age 75 if
           earlier)."




                                      6
<PAGE>   7


     (b)   the first paragraph of Rule 9C is deleted and replaced by the
           following:

           "A Member who ceases to be in Pensionable Employment before Normal
           Retiring Date without becoming entitled to a preserved pension will
           receive a refund of his contributions (less tax at 20% or such
           other rate as applies from time to time)."

4.   With effect from 1st October 1993 the definition of Plan Anniversary Date
     contained in rule 1 of the Rules is deleted and replaced by the following:

     ""Plan Anniversary Date" means the 1st October in each year up to and
     including 1991, the 1st August 1993, 1st October in each year
     thereafter."

5.   With effect from 15th November 1993 the following alterations are made to
     rule 2 of the Rules:

     (a)  at the end of the first sentence add the words "and shall
          apply up to and including 14th November 1993"

     (b)  at the end of Rule 2 add the following

          "On and after 15th November 1993 no further employees will be
          admitted to Plan membership except that

          (i)  Any Employee in Employment prior to 15th November
               1993 who had not at that time fulfilled the eligibility
               conditions but who has subsequently fulfilled the eligibility
               conditions for Eligible Category 1, Eligible Category 2 or
               Eligible Category 3 described above and has applied to join
               the Plan as required by the Trustees may be admitted to
               membership of the appropriate eligible category from the first
               of the month following fulfilment of the eligibility
               conditions."




                                      7
<PAGE>   8



            (ii) Any employee of the Employers will be eligible to
                 join the Plan for the benefit described in (ii) of Rule 7A
                 provided that

                 (a)  he has not attained his Normal Retiring Date
             
                 (b)  he attends work on the first day of his Employment

                 (c)  he is not provided with benefit of a similar nature 
                      under the Comshare Money Purchase Plan."

6.   With effect from 1st January 1994 the Rules are amended as follows:

     1.   The definition of Normal Retiring Date contained in rule 1 of
          the Rules is deleted and replaced by the following:-

          "Normal Retiring Date" means

          (i)    in respect of a Member who was a female Category
                 1 Employee and who was in Employment prior to 1st August 1992
                 and who died, left Pensionable Employment retired or attained
                 age 60 prior to 1st January 1994 her 60th birthday

          (ii)   in respect of any other Member who is a Category
                 1 Employee or Category 2 Employee the Member's 65th birthday

          (iii)  in respect of a Member who is a Category 3
                 Employee the Member's 63rd birthday unless the Category 3
                 Employee has elected to pay Category 3 Employee Contributions
                 (as deferred in Rule 3B) when it shall mean the Member's 60th
                 birthday."





                                      8
<PAGE>   9



      2.   Add a new definition after the definition of Overriding
           Appendix as follows:

           ""Pension Calculation Date" means in respect of a Category 1
           Employee who was in Employment prior to 1st August 1992 only the
           Member's 60th birthday."

      3.   Rules 5B, 5C and 5D are deleted and replaced by the
           following:

           "5B. LATE RETIREMENT

                With the Principal Employer's consent a Member who stays in
                Employment after Normal Retiring Date will receive a pension
                when he leaves Employment calculated as described in Rule 5A
                as if he had left at Normal Retiring Date and then increased
                on a basis certified as reasonable by an actuary to reflect
                Employment completed between Normal Retiring Date and the
                date of actual retirement.

                A Class B Member or Class C Member may alternatively choose
                to receive his pension as if he had left Employment at an
                earlier date (but not before Normal Retiring Date) and in
                this case the pension will only be increased to reflect any
                period for which pension is deferred after Normal Retiring
                Date.

                A Class A Member who is still in Employment when he reaches
                age 75 will be treated for all the purposes of the Plan as
                if he left Employment on his 75th birthday.






                                      9
<PAGE>   10






           5C. EARLY RETIREMENT (NOT INCAPACITY).

               A Member who leaves Employment (not for Incapacity) before
               Normal Retiring Date but after reaching age 50 may with the
               consent of the Principal Employer choose an immediate pension
               calculated as described in Rule 5A but based on the Member's
               Pensionable Employment and Final Pensionable Salary at the
               date of retirement unless the Member is in receipt of
               payments under the Comshare Limited Permanent Health
               Insurance Scheme when Final Pensionable Salary shall be the
               last Final Pensionable Salary received by the Member prior to
               the commencement of absence.  If the Trustees so decide this
               pension shall be reduced for early payment.
               
               If the Member is a Category 1 Employee whose Employment
               commenced on or after 1st August 1992 or a Category 2
               Employee or a Category 3 Employee any reduction will be on a
               basis decided by the Trustees and certified as reasonable by
               an actuary.
               
               If the Member is a Category 1 Employee whose Employment
               commenced prior to 1st August 1992 a reduction may be made on
               a basis decided by the Trustees provided that
               
               (i)  in respect of a male Member pension attributable to 
                    Pensionable Employment completed prior to 17th May 1990 
                    may only be reduced if retirement takes place prior to 
                    Normal Retiring Date and the reduction will reflect the 
                    period between actual retirement and Normal Retiring Date





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<PAGE>   11





                  (ii)  in respect of a female Member pension attributable to 
                        Pensionable Employment completed prior to 17th May 1990
                        may only be reduced if retirement takes place prior to 
                        Pension Calculation Date and the reduction will reflect
                        the period between actual retirement and Pension 
                        Calculation Date

                  (iii) pension attributable to Pensionable Employment 
                        completed after 17th May 1990 and prior to
                        1st January 1994 may only be reduced if retirement takes
                        place prior to Pension Calculation Date and the
                        reduction will reflect the period between actual
                        retirement and Pension Calculation Date

                  (iv)  pension attributable to Pensionable Employment 
                        completed after 1st January 1994 may be reduced if 
                        retirement takes place prior to Normal Retiring Date 
                        and will reflect the period between actual retirement 
                        and Normal Retiring Date

                  (v)   any reduction made is certified as reasonable by an 
                        actuary.

                  The Trustees must be reasonably satisfied that the immediate
                  pension is at least equal in value (i.e. taking account of
                  the longer period of payment) to the preserved pension
                  (including future increases under Rule 9B) payable from
                  Normal Retiring Date to which the Member would otherwise have
                  become entitled on leaving Employment.




                                     11
<PAGE>   12





                  In certain circumstances the benefit in Rule 7A (ii) may be
                  continued.  If this applies you will be informed.

              5D. EARLY RETIREMENT THROUGH INCAPACITY.

                  A Member who leaves Employment before Normal Retiring Date
                  through Incapacity may with the consent of the Principal
                  Employer  choose an immediate pension calculated as described
                  in Rule 5A but based on the Member's Pensionable Employment
                  and Final Pensionable Salary at the date of retirement unless
                  the Member is in receipt of payments under the Comshare
                  Limited Permanent Health Insurance Scheme when Final
                  Pensionable Salary shall be the last Final Pensionable Salary
                  received by the Member prior to the commencement of absence.
                  If the Trustees so decide this pension shall be reduced for
                  early payment in exactly the same way as the pension
                  described in Rule 5C.  The Trustees must be reasonably
                  satisfied that the immediate pension is at least equal in
                  value to the preserved pension (including future increases
                  under Rule 9B)  payable from Normal Retiring Date to which
                  the Member would otherwise have become entitled on leaving
                  Employment.

                  Until Normal Retiring Date the Trustees may from time to time
                  require evidence of continued Incapacity and if not satisfied
                  may suspend the pension for any period or periods before
                  Normal Retiring Date.  Any pensions payable on the Member's
                  death will be adjusted appropriately on the advice of an
                  actuary."

7.   With effect from 1st October 1994 the following alterations are made to
     Rule 7 of the Rules:

     (a)  at the start of paragraph (ii) of Rule 7A add the words

          "Subject to Rule 14G"



                                     12
<PAGE>   13

      (b)  at the start of paragraph (iii) of Rule 7A add the words

           "Subject to Rule 14G"

      (c)  rule 14G of the Rules is deleted and replaced by the
           following:

           "14G EVIDENCE OF HEALTH

           Where benefits payable on a Member's death are insured or reinsured
           with an Insurance Company, such benefits will be subject to any
           restrictions imposed by the Insurance Company and the Trustees will
           not be liable to pay any amount in excess of the amount actually
           paid by the Insurance Company.  The Trustees may also decide that
           these benefits will be reduced in respect of Members who are unable
           or who refuse to provide medical evidence satisfactory to the
           Trustees or whose death results from any special cause notified to
           the Members in writing."

8.   With effect from 21 August 1996 the following alterations are made to
     Rule 1:

     (a)  The definition of "Final Pensionable Salary" in Rule 1 is
          deleted and replaced by the following:

          ""FINAL PENSIONABLE SALARY" means unless it is otherwise agreed by
          letter between the Member and the Principal Employer,

          (i)  in respect of a Category 1 Employee or a Category
               2 Empoyee the highest annual average of the Member's
               Pensionable Salary for any period of three consecutive years
               within the 10 years immediately preceding the Member's Normal
               Retiring Date, or, if earlier, the Member's actual retirement
               date, date of leaving Pensionable Employment or death or

          (ii) in respect of a Category 3 Employee the greater
               of the definition previously described (except that no
               deductor shall be imposed upon Pensionable Salary) and the



                                     13
<PAGE>   14

               Member's basic annual salary in any one year in the last five
               years before the Member's Normal Retiring Date, or, if
               earlier, the Member's actual retirement date, date of leaving
               Pensionable Employment or death, plus the annual average of
               any profit related pay, any commission received, any bonus
               received or due but not paid, in which case it shall be
               considered to have been paid in the year in which it was due
               and the notional value of any benefits in kind which are
               assessable to income tax as emoluments under Schedule E, in
               the three years up to 30th June immediately before the Plan
               Anniversay Date on which basic salary is determined PROVIDED
               THAT with effect from 21 August 1996 no amount in excess of
               130% of basic annual salary will count as Final Pensionable
               Salary

      (b)  the definition of Pensionable Salary is amended as follows:

            ""PENSIONABLE SALARY" means unless it is otherwise agreed by
            letter:

            (i)  in the case of a Category 1 Employee or a Category 2 Employee
                 the Member's basic annual salary or wages, plus any shift 

                 allowance or disturbance allowance on the date of joining the
                 Plan and on each subsequent Plan Anniversary Date, plus the
                 annual average of any performance related pay any commission
                 received or bonus due or received in the three years up to 30
                 June immediately before the Plan Anniversary Date on which
                 salary is determined less 1.25 times the annual equivalent of
                 the Lower Earnings Limit on the 6 April immediately preceding
                 the Plan Anniversary Date
        
            (ii) in the case of a Category 3 Employee the Member's basic annual
                 salary or wages, plus any shift allowance or disturbance 
                 allowance on the date of joining the Plan and on each 
                 subsequent Plan Anniversary Date, plus the annual average
                 of any performance related pay any commission 


                                     14
<PAGE>   15

                 received or bonus due or received and the notional value of 
                 any benefits in kind which are assessable to income tax as 
                 emoluments under Schedule E in the three years up to 30 June 
                 immediately before the Plan Anniversary Date on which salary 
                 is determined
        
                 PROVIDED THAT

                 (1)  any bonus shall only be counted once

                 (2)  with effect from 21 August 1996 no amount in excess of 
                      110 per cent of Planned Earnings will count as 
                      Pensionable Salary in respect of a Category 1 Employee

                 (3)  with effect from 21 August 1996 no amount in excess of 
                      130% of basic annual salary will count as Pensionable 
                      Salary in respect of a Category 3 Employee"

      (c)  a new definition is introduced after the definition of Plan
           ANNIVERSARY DATE:

           ""PLANNED EARNINGS" means in respect of a Category 1 Member his
           basic annual salary on the Plan Anniversary Date in each year plus
           the annual average of the Category 1 Member, commission received in
           the three years up to 30 June immediately before the Plan
           Anniversary Date on which Salary is determined (no deduction will
           be made from Planned Earnings to account for State benefits)"

9.   With effect from the date of this deed the following amendments are made:

     A.    The following references throughout the Rules are altered and
           the GMP Model Rules appended to this deed are adopted and the
           Overriding Appendix GMP Model Rules are deleted.



                                     15
<PAGE>   16

            (1)  CONTENTS

                 The final item "OVERRIDING APPENDIX - GMP MODEL RULES" is
                 deleted and replaced by "GMP MODEL RULES".

            (2)  RULE 1

                 (a)  the definition of "GMP" is deleted and replaced by the 
                      following:

                      ""GMP" has the meaning given to it in the GMP Model
                      Rules".

                 (b)  A new definition is inserted following the definition of
                      "GMP" as follows:

                      ""GMP MODEL RULES" means the GMP Model Rules which are
                      included at the end of these Rules."

                 (c)  The definition of "OVERRIDING APPENDIX" is deleted.
                      

                 (d)  The last sentence of Rule 1 is deleted and replaced by 
                      the following:

                      "Words and expressions used in the GMP Model Rules are
                      defined in Rule 1 of those Rules."

             (3) In the heading to Rule 2 the words in brackets are deleted and
                 replaced by the following:

                 "(See also Rule 4 of the GMP Model Rules)"

             (4) In the heading to Rule 5 the words in brackets are deleted and
                 replaced by the following:

                 "(See also Rules 5 and 6 of the GMP Model Rules)"



                                     16
<PAGE>   17



            (5)  In the heading to Rule 6 the words in brackets are deleted and
                 replaced by the following:

                 "(see also Rule 12 of the GMP Model Rules)"

            (6)  In the heading to Rule 8 the words in brackets are deleted and
                 replaced by the following:

                 "(see also Rule 5 of the GMP Model Rules)"

            (7)  In the heading to Rule 9 the words in brackets are deleted and
                 replaced by the following:

                 "(see also Rules 5, 6, 8 and 18 of the GMP Model Rules)"

            (8)  Paragraph (a) of Rule 9B is deleted and replaced by the 
                 following:

                 "(a) the GMP will be increased as described in Rule 7.1 of 
                      the GMP Model Rules, and "

            (9)  In the heading to Rule 10 the words in brackets are deleted 
                 and replaced by the following:

                 "(see also Rule 6 of these Rules and Rules 6, 7, 10 and 11
                   of the GMP Model Rules)"

            (10) Paragraph (d) of Rule 10D is deleted and replaced by the 
                 following:

                 "(d) where GMP is bought out the policy must satisfy the 
                      requirements of Rule 10.1(2) of the GMP Model Rules"



                                     17
<PAGE>   18



            (11) The following alterations are made to Rule 10E of the Rules
           
                 (i)  in the first paragraph the words "Rule 9.1 of the 
                      Overriding Appendix are satisfied" are deleted and 
                      replaced by "Rule 10.1 of the GMP Model Rules are 
                      satisfied."

                 (ii) at the end of the second paragraph the words "Rule 10 of 
                      the Overriding Appendix" are deleted and replaced by 
                      "Rule 11 of the GMP Model Rules".

            (12) The following alteration is made to Rule 11E

                 delete the words "Rule 1.1 of the Overriding Appendix" in
                 the second line and replace them with "Rule 1 of the GMP
                 Model Rules."

            (13) Rule 13 is amended by the deletion of the words
                 "Overriding Appendix" and the insertion of the words "GMP
                 Model Rules".

            (14) In the heading to Rule 14 the words in brackets
                 are deleted and replaced by the following:

                 "(see also Rules 7, 16 and 17 of the GMP Model Rules)"

            (15) Rule 14A is amended by the deletion of the second
                 paragraph and the insertion of the following:

                 "The GMP portion of each pension in payment will be
                 increased as described in Rule 7 of the GMP Model Rules".

            (16) In the heading to Rule 15 the words in brackets are deleted 
                 and replaced by the following

                 "(See also Rules 6, 9, 10, 11 and 12 of the GMP Model Rules)"




                                     18
<PAGE>   19



            (17) Rule 15B is amended by the deletion of the second
                 paragraph and the insertion of the following:

                 "A GMP may be commuted for a lump sum on grounds of
                 triviality only if the conditions of Rule 12 of the GMP
                 Model Rules are satisfied."

            (18) The first paragraph of Rule 15D is amended by the
                 deletion of the words from the opening of the second set of
                 brackets to the end of the paragraph and the insertion of the
                 following:

                 "in Rule 1 of the GMP Model Rules) shall be subject to the
                 conditions of Rule 6.2 and 9 of the GMP Model Rules."

            (19) The following alterations are made to Rule 15E o fthe Rules:
                 

                 (i)  The fourth paragraph is deleted and replaced by:
                      

                       "A transfer of GMP may be made only if the
                        conditions of Rule 10.1 of the GMP Model Rules are
                        satisfied."

                 (ii)  In the fifth paragraph the words "Rule 10 of the 
                       Overriding Appendix" are deleted and replaced by:

                       "Rule 11 of the GMP Model Rules."

            (20) Rule 15F is amended by the deletion of the words "Rule 9.1(2)
                 of the Overriding Appendix" at the end of the first paragraph 
                 and the insertion of the following:

                 "Rule 10.1(2) of the GMP Model Rules."




                                     19
<PAGE>   20

            (21) In the heading to Rule 22 the words in brackets are deleted 
                 and replaced by the following:

                 "(see also Rule 14 of the GMP Model Rules)"

            (22) In the heading to Rule 23 the words in brackets are deleted 
                 and replaced by the following:

                 "(See also Rule 3 of the GMP Model Rules)".

       B.   (1)  CONTENTS: Page 3 is amended:

                 (i)  by the insertion of (1) after the number 22
                 

                 (ii) by the insertion of "22(2) FROZEN PLAN" after "22H".


            (2)  Rule 1 is amended by the insertion of the following 
                 definition after the definition of "Member":

                 "MONEY PURCHASE SECTION" means the section of the Plan which
                 commenced on 1 April 1997 and is described to Members in the
                 announcement issued in February 1997."

            (3)  Rule 2 is amended

                 (a)  by deletion of the words;
                 
                     "On and after 15 November 1993 no further employees
                      will be admitted to Plan membership except that"

                      and the insertion of the following in their place

                      "Between 15 November 1993 and 1 April 1997 no further
                      employees will be admitted to Plan membership except
                      that"




                                     20
<PAGE>   21


                 (b)     at the end of Rule 2 add the following:


                         "On and after 1 April 1997 any Employee of the
                         Employer who has attained age 18 may join the Money
                         Purchase Section of the Plan."

            (4)  The heading of Rule 22 is amended as follows:

                         "22  (1) TERMINATION OF THE PLAN (See also 
                                  Rule 14 of the GMP Model Rules)"

            (5)  Sub-Rules 22A, 22B, 22C, 22D, 22E, 22F, 22G, 22H are 
                 renumbered 22(1)A, 22(1)B, 22(1)C, 22(1)D, 22(1)E, 22(1)F,
                 22(1)G and 22(1)H

            (6)  A new sub-rule is added after Rule 22(1)

                 "22  (2) FROZEN PLAN

                          The Principal Employer and the Trustees may at
                          any time resolve that the Plan or a section of
                          it shall be treated as a frozen Plan.

                          If such resolutions are made no further contributions
                          shall be made or benefits accrue to the Plan or the 
                          section of the Plan concerned.

                          While the Plan or a section of it is frozen the
                          power of alteration may continue to be exercised
                          by the Principal Employer and the Trustees and
                          the Plan will continue to be administered by the
                          Trustees.
                          
                          Expenses of the Plan or the section of the Plan
                          will continue to be met by the Principal Empoyer
                          or from the Plan or the appropriate section of
                          the Plan if the Principal Employer and the
                          Trustees agree."
                          



                                     21
<PAGE>   22


            (7)  Rule 21B is amended as follows:

                 in the second and third paragraphs references to Rules "22B,
                 C and D" are deleted and replaced by

                 "22(1)B, 22(1)C and 22(1)D" as appropriate.


IN WITNESS whereof this Deed has been entered into the day and year first above
written



THE COMMON SEAL of
COMSHARE LIMITED
was affixed to this Deed
in the presence of:




Director /s/ Kathryn A. Jehle                                [SEAL]     
        -----------------------------

Secretary  /s/ David H. Mackenzie
          ---------------------------


SIGNED AND DELIVERED AS A DEED
by the said DAVID HUNTER MACKENZIE                    /s/ David H. Mackenzie
in the presence of:                                  ------------------------   



Witness  /s/ F.O. OBILEYE
        --------------------------

Address  22 CHELSEA MANOR STREET, 
        --------------------------

         LONDON
----------------------------------

         SW3 5RL
----------------------------------

Occupation  Administrative Assistant
           -----------------------------




                                     22
<PAGE>   23





SIGNED AND DELIVERED AS A DEED
by the said DION O'LEARY                                /s/ Dion O'Leary        
in the presence of:                                  -----------------------    


Witness /s/ S. Watkinson
       ------------------------

Address  22 Chelsea Manor Street, 
        ---------------------------

        London, 
-----------------------------------

        SW3 5RL
-----------------------------------

Occupation  HR Manager
           ------------------------


SIGNED AND DELIVERED AS A DEED
by the said KATHRYN JEHLE                               /s/ Kathryn A. Jehle
in the presence of:                                   ------------------------  


Witness  /s/ C. Potter
        -------------------------

Address  22 Chelsea Manor Street, 
        ----------------------------

        London
------------------------------------

        SW3 5RL
-------------------------------------

Occupation  Accountant
           ------------------


SIGNED AND DELIVERED AS A DEED
by the said NICHOLAS PAUL SEATON BRAY                   /s/ Nicholas P.S. Bray
in the presence of:                                    ------------------------ 


Witness  /s/ G. Halliman
        --------------------

Address  63 Toll Bar Ct., 
        --------------------

Basinghall Gons, 
----------------------------

Sutton, Surrey, SM2 6AV
----------------------------

Occupation  Office Manager                      
           -----------------

SIGNED AND DELIVERED AS A DEED                          /s/ Mary Ann Moore
by the said MARY ANN MOORE                             ------------------------ 
in the presence of:


Witness  /s/ G. Sollis
        ---------------------
Address  22 Chelsea Manor Street, London, SW3 5RL
       ------------------------------------------
Occupation Legal Secretary
          --------------------


                                      23
<PAGE>   24


                     CONTRACTED-OUT SALARY RELATED SCHEMES

                                GMP MODEL RULES

     SECTION A:                 THE BASIC RULES

1.   DEFINITIONS

2.   OVERRIDING EFFECT OF THESE GMP MODEL RULES

3.   ALTERATIONS TO THESE GMP MODEL RULES

     3.1  Power to alter GMP Model Rules
     3.2  OPB consent

4.   MEMBERSHIP OF THE SCHEME

5.   ENTITLEMENT TO GMP


     5.1  Guaranteed Minimum
     5.2  Member's GMP
     5.3  Widow's GMP
     5.4  Payment of Widow's GMP
     5.5  Widower's GMP
     5.6  Payment of Widower's GMP
     5.7  Offsetting pension against GMP


6.   REVALUATION OF GMP


     6.1  Revaluation before State Pensionable Age
     6.2  Transfers in
     6.3  Transfers out




                                     24

<PAGE>   25





7.    INCREASE OF GMP

      7.1 Increase after State Pensionable Age
      7.2 Increase after State Pensionable Age or Member's death

8.    ANTI-FRANKING

9.    TRANSFERS INTO THE SCHEME

      9.1  Acceptance of transfers
      9.2  Effect of transfers

10.   TRANSFERS OUT OF THE SCHEME

      10.1 Conditions for transfer of GMPs
      10.2 Effect of such transfers

11.   TRANSFER PREMIUMS

12.   COMMUTATION OF GMP

      12.1 Circumstances in which GMP may be commuted
      12.2 Commutation Condition

13.   SECURING GMPs

14.   WINDING UP THE SCHEME


      14.1  Priorities on winding-up
      14.2  Order of priorities
      14.3  Voluntary contributions


15.   SCHEME CEASES TO BE A CONTRACTED-OUT SALARY RELATED SCHEME

16.   SUSPENSION OF GMP




                                     25
<PAGE>   26


17.  FORFEITURE OF GMP

18.  CONTRIBUTIONS EQUIVALENT PREMIUMS

     SECTION B: THE EMPLOYER'S COMPULSORY ALTERNATIVES


     SECTION C:  THE EMPLOYER'S VOLUNTARY OPTIONS

     SECTION D:  CERTIFICATE TO CONFIRM WHICH PARTS OF SECTIONS B AND C HAVE 
                 BEEN INCORPORATED INTO SECTION A OF THE MODEL RULES








                                     26
<PAGE>   27





Interpretation : References to any legislation or any provision includes
references to any previous legislation or provision relating to the same
subject matter and to any modification or re-enactment for the time being in
force

                     CONTRACTED-OUT SALARY RELATED SCHEMES

                                GMP MODEL RULES

                                   SECTION A
1.    DEFINITIONS

      In these GMP Model Rules the following words have the following
      meanings:-

      "THE ACT" means the Pension Schemes Act 1993.

      "ACTUARY" means a Fellow of the Institute of Actuaries or a Fellow of the
      Faculty of Actuaries, or a person with other actuarial qualifications who
      is approved by the Secretary of State for Social Security, at the request
      of the Trustees, as being a proper person to act in this capacity.

      "CONTRACTED-OUT EMPLOYMENT" means a Member's contracted-out employment by
      reference to the Scheme (as in section 8(1)(a)(i) and 8(1)(b) of the
      Act).

      "FIXED RATE REVALUATION" means the method of revaluing a GMP before State
      Pensionable Age described in Rule 6.1 (C) below.

      "GMP" means the guaranteed minimum pension of a Member, Widow or Widower
      as defined in the Act.

      "INSURER" means an insurance company, an EC company or a friendly society
      as defined in regulation 30 of the Occupational Pension Schemes
      (Contracting-out) Regulations 1984 (SI 1984/380) as amended by regulation
      2 of SI 1995/35.




                                     27
<PAGE>   28

      "LIMITED REVALUATION" means the method of revaluing a GMP before State
      Pensionable Age described in Rule 6.1 (B) below.

      "MEMBER" means a member of the Scheme (including a person who is not in
      the pensionable service of any employer participating in the Scheme but
      to whom, or in respect of whom, benefits are still immediately or
      prospectively payable under the Scheme in respect of previous membership
      of the Scheme or another scheme).

      "NORMAL RETIRING DATE" means the day on which a Member attains normal
      pension age (within the meaning of the Act) under the Scheme.

      "PROTECTED RIGHTS" has the same meaning as in section 10 of the Act.

      "QUALIFYING SERVICE" has the same meaning as in section 71(7) of the Act.

      "RULE" (followed by a number) means the Rule (with that number) in this
      Appendix.

      "SCHEME" means this occupational pension scheme.

      "SECTION 53 MONEY PURCHASE SCHEME" means a scheme which was a
      contracted-out scheme, providing protected rights and satisfying section
      9(3) of the Act, and which the Occupational Pensions Board are under a
      duty to supervise under section 53 of the Act.

      "SECTION 53 SALARY RELATED SCHEME" means a scheme which was a
      contracted-out scheme, providing guaranteed minimum pensions and
      satisfying section 9(2) of the Act, and which the Occupational Pensions
      Board are under a duty to supervise under section 53 of the Act.

      "SECTION 148 REVALUATION" means the method of revaluing a GMP before
      State Pensionable Age described in Rule 6.1 (A) below.

      "SHORT SERVICE BENEFIT" means the benefit to which an early leaver who
      satisfies the qualifying conditions must be entitled under the
      preservation requirements.




                                     28
<PAGE>   29

      "STATE PENSIONABLE AGE" means a man's 65th birthday and a woman's 60th
      birthday.

      "TRUSTEES" means the trustees or administrators of the Scheme.

      "WIDOW" and "WIDOWER" mean respectively the widow and the widower of a
      Member.  If a Member has married under a law which allows polygamy and,
      on the day of the Member's death, has more than one spouse, the Trustees
      must decide which, if any, survivor is the Widow or Widower.  In reaching
      that decision, the Trustees must have regard to the practice of the
      Department of Social Security and any relevant provisions of existing
      Social Security legislation, in particular section 17(5) of the Act and
      regulation 2 of the Social Security and Family Allowance (Polygamous
      Marriages) Regulations 1975 (SI 1975/561).

2.    OVERRIDING EFFECT OF THESE GMP MODEL RULES

      These Rules shall apply if any Member's employment becomes Contracted-out
      Employment by reference to the Scheme and the Scheme is not
      contracted-out on a money purchase basis.  These Rules will only apply
      for so long as anyone has a GMP or a prospective right to receive a GMP
      under the Scheme which subjects the Scheme to the continuing supervision
      of the Occupational Pensions Board.

      These Rules override any inconsistent provisions elsewhere in the Scheme
      except provisions which are necessary in order that Inland Revenue
      approval for the purposes of Chapter I of Part XIV of the Income and
      Corporation Taxes Act 1988 is not prejudiced.

3.    ALTERATIONS TO THESE GMP MODEL RULES

      3.1  POWER TO ALTER GMP MODEL RULES. The persons or bodies having
           the power of alteration in relation to the rest of the Scheme may at
           any time in writing make any alteration to these GMP Model Rules
           necessary to comply with the contracting-out requirements of the 



                                     29
<PAGE>   30

           Act applicable to salary related contracted-out schemes and Section
           53 salary related schemes.  This power of alteration may be
           exercised by them without any condition except the one in 3.2 below. 
           It is additional to, and independent of, any other power of 
           alteration in relation to the Scheme.
        
      3.2  OPB CONSENT.  No alteration to these GMP Model Rules may be
           made without the consent of the Occupational Pensions Board.  This
           applies whether the alteration is made under 3.1 above or under any
           other power of alteration in relation to the Scheme.

4.    MEMBERSHIP OF THE SCHEME

      Membership of the Scheme must be open to persons who enter employment to
      which the Scheme relates more than 6 years before Normal Retiring Date.
      If the Scheme has an annual entry date, this 6 year period may be
      increased to a period of 6 years plus the part of a year until the next
      entry date.  Where the Scheme and one or more other contracted-out
      schemes relate to employment with the same employer, those schemes may be
      treated as if they were a single scheme in deciding whether the
      requirements of this Rule are satisfied.

5.    ENTITLEMENT TO GMP

      5.1  GUARANTEED MINIMUM.  This Rule 5 applies to a Member, Widow
           or Widower where the Member has a guaranteed minimum in relation to
           the pension provided for the Member under the Scheme in accordance
           with section 14 of the Act.

      5.2  MEMBER'S GMP.  The Member shall be entitled to a pension for
           life paid at a rate equivalent to a weekly rate of not less than
           that guaranteed minimum.  The pension will be paid from State
           Pensionable Age but commencement of the pension may be postponed for
           any period during which the Member remains in employment after State
           Pensionable Age:-



                                     30
<PAGE>   31


           (1)  if the employment is employment to which the Scheme relates and
                the postponement is not for more than 5 years after State 
                Pensionable Age; or

           (2)  if the Member consents to the postponement.

      5.3  WIDOW'S GMP.  Where the Member is a man and dies at any time
           leaving a Widow, she shall be entitled, subject to 5.4 below, to
           receive a pension from the Scheme paid at a rate equivalent to a
           weekly rate of not less than half that guaranteed minimum.

      5.4  PAYMENT OF WIDOW'S GMP. [See Section B]

      5.5  WIDOWER'S GMP. Where the Member is a woman and dies at any
           time on or after 6 April 1989 leaving a Widower, he shall be
           entitled, subject to 5.6 below, to receive a pension from the Scheme
           paid at a rate equivalent to a weekly rate of not less than half of
           that part of the guaranteed minimum which is attributable to
           earnings for the tax year 1988/1989 and subsequent tax years.

      5.6  PAYMENT OF WIDOWER'S GMP. [See Section B]

      5.7  OFFSETTING PENSION AGAINST GMP.  Any pension payable to the
           Member, Widow or Widower under any other provision of the Scheme may
           be offset against the pension entitlement under this Rule 5 except
           to the extent that:-

           (1)  any part of the pension is an equivalent pension benefit within
                the meaning of the National Insurance Act 1965; or

           (2)  any part of the pension is an increase, calculated in 
                accordance with Schedule 3 of the Act and added to the amount 
                that would be payable but for Chapter II of Part IV of the Act
                or regulations made under it; or

           3)   offsetting would contravene the anti-franking legislation (see 
                Rule 8 below).



                                     31
<PAGE>   32

6.    REVALUATION OF GMP

      6.1  REVALUATION BEFORE STATE PENSIONABLE AGE. Where a Member
           ceases to be in Contracted-out Employment before State Pensionable
           Age, the Member's GMP at State Pensionable Age or at the Member's
           earlier death will be calculated by increasing the accrued rights to
           GMP at cessation of Contracted-out Employment under one of the
           options (A), (B) or (C) below.

           (A)    SECTION 148 REVALUATION.

                  The increase will be by the percentage by which earnings
                  factors for the tax year in which Contracted-out Employment
                  ceases are increased by the last order under section 148 of
                  the Social Security Administration Act 1992 to come into
                  force before the tax year in which the Member reaches State
                  Pensionable Age (or dies, if earlier).

           (B)    LIMITED REVALUATION.

                  The increase will be by the lesser of:-

                  (1)  5 per cent (5%) compound for each tax year after that 
                       in which Contracted-out Employment ceases up to and 
                       including the last complete tax year before the Member 
                       reaches State Pensionable Age (or dies, if earlier); and

                  (2)  the percentage by which earnings factors for the tax 
                       year in which Contracted-out Employment ceases are 
                       increased by the last order under section 148 of the 
                       Social Security Administration Act 1992 to come into 
                       force before the tax year in which the Member reaches 
                       State Pensionable Age (or dies, if earlier).

                  The Trustees must pay a limited revaluation premium in
                  respect of the Member to the Secretary of State for Social
                  Security.




                                     32
<PAGE>   33



            (C)    FIXED RATE REVALUATION.

                   The increase will be by such rate as regulations made under
                   section 55(5) of the Act specify as being relevant at the
                   date Contracted-out Employment ceases, for each complete tax
                   year after the tax year containing that date up to and
                   including the last complete tax year before the Member
                   reaches State Pensionable Age (or dies, if earlier).

            The Trustees and the principal employer participating in the Scheme
            shall decide which of the options (A), (B) or (C) applies to the
            Scheme.  They may at any time decide that one of the other two
            methods shall be used, instead of the method currently being used,
            for all Members ceasing to be in Contracted-out Employment after a
            specified date.  They must notify the Occupational Pensions Board
            whenever the method of revaluation for the Scheme is changed.

      6.2   TRANSFERS IN. Where a transfer payment is received in respect
            of a Member from another scheme ("the transferring scheme") which
            includes accrued rights of the Member to a GMP (or includes
            protected rights in respect of which the receiving scheme will
            provide a GMP) the earnings factors used in calculating that GMP
            will normally be revalued using Section 148 Revaluation during the
            Member's Contracted-out Employment, and 6.1 above will apply if that
            Contracted-out Employment ceases before State Pensionable Age.  The
            Trustees may, however, decide, if the provisions of the transferring
            scheme so allow, to use either Limited Revaluation or Fixed Rate
            Revaluation from the date on which the Member ceased to be in
            contracted-out employment by reference to the transferring scheme
            until the Member attains State Pensionable Age (or dies, if earlier)
            but:-




                                     33
<PAGE>   34




            (1)  Limited Revaluation may not be used as regards any part of the
                 GMP being transferred which arose from contracted-out 
                 employment in relation to a previous scheme and which the 
                 transferring scheme is already revaluing by Fixed Rate 
                 Revaluation (or vice versa); and

            (2)  the Trustees may not make that decision if, on becoming a 
                 Member, the Member's contracted-out employment in relation to 
                 a previous scheme is treated as continuing for the purposes 
                 of the Act.

            Where, under this Rule 6.2, Limited Revaluation is to be used, the
            Trustees shall have power to pay out of the transfer payment in
            respect of that Member any limited revaluation premium payable as a
            result of the Member ceasing to be in contracted-out employment by
            reference to the transferring scheme.

            Where the Scheme accepts the proceeds of, or the assignment of, an
            insurance policy which consists of, or includes, accrued rights to
            GMP, the Trustees may use either Section 148 Revaluation or the
            method of revaluation that was in use under the policy (and
            condition (1) above applies).

      6.3   TRANSFERS OUT. Where a Member's accrued rights to GMP are
            transferred to another contracted-out salary related scheme or to a
            Section 53 salary related scheme, the Trustees may agree with the
            administrator of that scheme that the Member's GMP shall, instead of
            being revalued using the method currently being adopted under 6.1
            above, be revalued using another method which would be permitted if
            that scheme contained a rule in the same terms as 6.2 above but,
            where Limited Revaluation is to be used, that administrator must
            make arrangements for the payment of any limited revaluation premium
            (unless it has already been paid by the Trustees).





                                     34
<PAGE>   35


7.    INCREASE OF GMP

      7.1  INCREASE AFTER STATE PENSIONABLE AGE.  If the commencement of
           any Member's GMP is postponed for any period after State Pensionable
           Age, that GMP shall be increased to the extent, if any, specified in
           section 15 of the Act.

      7.2  INCREASE AFTER STATE PENSIONABLE AGE OR MEMBER'S DEATH.  Any
           GMP to which a Member, Widow or Widower is entitled under Rule 5
           above shall, insofar as it is attributable to earnings in the tax
           years from and including 1988/1989, be increased in accordance with
           the requirements of section 109 of the Act.

8.    ANTI-FRANKING

      Except as provided in sections 87-92 and 110 of the Act, no part of a
      Member's, Widow's or Widower's pension under the Scheme may be used to
      frank an increase in the Member's, Widow's or Widower's GMP under Rule 6
      or Rule 7 above.

9.    TRANSFERS INTO THE SCHEME

      9.1. ACCEPTANCE OF TRANSFERS. The Trustees may accept:-

           (1)  a transfer payment in respect of the Member's accrued rights to
                GMPs under a contracted-out salary related scheme, a Section 53
                salary related scheme or a policy of insurance or an annuity 
                contract of the type described in section 19 of the Act;

           (2)  a transfer of the liability for the payment of GMPs to, or in 
                respect of, any person who has become entitled to them;

           (3)  a transfer of Protected Rights

                (a)  in respect of the Member or a former Member from another 
                     scheme which is, or was, an appropriate personal pension 
                     scheme;



                                     35
<PAGE>   36


                   (b)  in respect of the Member or a former Member from 
                        another scheme which is, or was, a scheme 
                        contracted-out on a money purchase basis or a
                        Section 53 money purchase scheme.

           Transfers may be accepted only as provided in the appropriate
           regulations.

      9.2  EFFECT OF TRANSFERS. Where a transfer is accepted under
           9.1(1) above, the Member's accrued rights to GMPs under the Scheme
           will be increased accordingly.

           Where a transfer is accepted under 9.1(3) above, the Member's,
           Widow's and Widower's GMPs under the Scheme will be increased by
           amounts equal to the GMPs to which they would have been treated as
           entitled by reason of the Member's membership of the transferring
           scheme if the transfer payment had not been made.

10.   TRANSFERS OUT OF THE SCHEME

      10.1 CONDITIONS FOR TRANSFER OF GMPS.  A transfer payment made out
           of the Scheme may include a Member's accrued rights to GMPs or the
           liability for the payment of GMPs to, or in respect of, any person
           who has become entitled to them only if the following conditions are
           fulfilled.  These conditions depend on the type of scheme, policy or
           contract to which the transfer is being made.

           (1) ALL SCHEMES AND ARRANGEMENTS

               The Member must consent to the transfer unless:-

               (a) it is made to another contracted-out salary related scheme
                   or a Section 53 salary related scheme where either the 
                   scheme is a scheme of the same employer or the transfer
                   involves all of, or a group of, the Members, and either the
                   transfer results from a 



                                     36
<PAGE>   37

                    financial transaction between the Member's old and new
                    employers, or the receiving scheme is a scheme of an
                    employer connected with the Member's old employer for the
                    purposes of section 35 of the Act. The transfer must be
                    made in accordance with the appropriate regulations (SI
                    1991/167) which may involve an actuarial certificate;
        
                (b) it is to allow benefits to be bought out where the Member 
                    has less than 5 years Qualifying Service, or to allow the 
                    Trustees to buy out the benefits of the Widow or Widower of
                    such a Member.

                The transfer will be subject to any requirements of the
                Inland Revenue.
                
                The receiving scheme, policy or contract must be an
                appropriate personal pension scheme, a contracted-out
                occupational pension scheme, a Section 53 money purchase
                scheme, a Section 53 salary related scheme, an overseas
                occupational pension scheme to which the Occupational
                Pensions Board approve the transfer, or an insurance policy
                or annuity contract of the type described in section 19 of
                the Act.
                
           (2)  CONTRACTED-OUT SALARY RELATED SCHEMES AND SECTION 19 INSURANCE
                POLICIES OR ANNUITY CONTRACTS

                The receiving scheme, policy or contract must provide the
                Member and the Member's Widow or Widower with GMPs equal to
                their accrued GMPs under the Scheme up to the date of
                transfer, together with revaluation until the Member reaches
                State Pensionable Age (or dies, if earlier). In the case of
                GMPs already in payment, the receiving scheme must provide
                for the pensions to commence from the date from which
                liability for payment has been assumed by it, and for the
                conditions of payment relating to its own GMPs to apply
                equally to such pensions.
                



                                     37
<PAGE>   38

            (3)  ALL OCCUPATIONAL PENSION SCHEMES (EXCEPT OVERSEAS SCHEMES 
                 COVERED BY (6))

                 The Member must have entered employment with an employer
                 which is (or, in the case of a Section 53 scheme, is or was)
                 a contributor to the receiving scheme.  If the employment is
                 not contracted-out, the transfer must be in accordance with
                 regulations 2(4) and 2A(4) of SI 1985/1323.
                 
            (4)  APPROPRIATE PERSONAL PENSION SCHEMES AND OCCUPATIONAL PENSION
                 SCHEMES WHICH ARE OR WERE CONTRACTED-OUT BY THE MONEY 
                 PURCHASE TEST

                 That part of the transfer payment which relates to the
                 Member's accrued rights to GMPs must be of an amount at
                 least equal to the cash value of those accrued rights and
                 applied by the receiving scheme in providing money purchase
                 benefits for, or in respect of, the Member.
                 
            (5)  SECTION 53 MONEY PURCHASE OR SECTION 53 SALARY RELATED SCHEMES

                 No transfer payment may be made to such a scheme without the
                 approval of the Occupational Pensions Board, who may impose
                 any conditions they consider appropriate.
                 
            (6)  OVERSEAS OCCUPATIONAL PENSION SCHEMES NOT COVERED BY (2), (4)
                 OR (5) ABOVE

                 The Member must have entered employment outside the United
                 Kingdom to which the receiving scheme applies.
                 
                 No transfer payments may be made to such a scheme without
                 the approval of the Occupational Pensions Board, who may
                 impose any conditions they consider appropriate.
                 


                                     38
<PAGE>   39

      10.2 EFFECT OF SUCH TRANSFERS.  Where the Member's accrued rights
           to GMPs or liability for GMPs already in payment are transferred in
           accordance with 10.1 above, the Member and the Member's Widow or
           Widower will cease to have any entitlement to a GMP under the
           Scheme.  If the transfer does not relate to the whole of the
           Member's rights to benefits under the Scheme, the Member's remaining
           benefits under the Scheme may be reduced to allow for the fact that
           the Member's GMP rights have been transferred.

11.   TRANSFER PREMIUMS

      Where a Member ceases to be in Contracted-out Employment before Normal
      Retiring Date and the Member's accrued rights to benefits (other than
      GMPs) are transferred to another occupational pension scheme which is
      neither a contracted-out scheme nor one which was formerly contracted-out
      and which remains under the supervision of the Occupational Pensions
      Board in accordance with section 53 of the Act, or to a non-appropriate
      personal pension scheme, the Trustees may elect to pay a transfer premium
      to the Secretary of State for Social Security.  No such election may be
      made where the Member has completed less than 2 years'  Qualifying
      Service or where an accrued rights premium is payable in respect of the
      Member.

      Where a transfer premium is paid, the Member's accrued rights to GMPs
      under the Scheme shall be extinguished.

12.   COMMUTATION OF GMP

      12.1 CIRCUMSTANCES IN WHICH GMP MAY BE COMMUTED.

           (1)  MEMBER'S GMP.  The Member's GMP may be commuted if the 
                Commutation Condition is satisfied and all the Member's
                other benefits under the Scheme are being commuted, and

                (a)  the benefits have become payable; or

                (b) the Scheme is being wound up.



                                     39
<PAGE>   40

            (2)  WIDOW'S OR WIDOWER'S GMP.  The Widow's or Widower's GMP may be
                 commuted if the Commutation Condition is satisfied and all the
                 Widow's or Widower's other benefits under the Scheme are being
                 commuted, and

                 (a) the benefits have become payable; or

                 (b) the Member's benefits are being commuted on grounds of 
                     triviality.

            (3)  MORE THAN ONE RETIREMENT BENEFIT SCHEME RELATING
                 TO THE SAME EMPLOYMENT.  If the Member is a member of more
                 than one retirement benefit scheme relating to the same
                 employment the requirements of this Rule must be satisfied by
                 all of the schemes.

      12.2  COMMUTATION CONDITION.  The Commutation Condition is that the
            aggregate of the pensions and the pension equivalent of any lump sum
            benefits to which the person is entitled under the Scheme, and under
            all other retirement benefit schemes relating to employment with the
            same employer as the employment in respect of which the benefits are
            payable, does not exceed L.260 per annum (or such greater amount as
            may be prescribed by regulations made under section 21 and section
            77 of the Act and is permitted by the Inland Revenue).  In
            addition:-

            (1)  Where commutation is taking place before State Pensionable 
                 Age, other than on the death of the Member, Limited
                 Revaluation or Fixed Rate Revaluation must be applied to any
                 GMP included in the aggregate pension, and such GMP must be
                 revalued to State Pensionable Age for the purposes of
                 calculating that aggregate.  For this purpose, Limited 
                 Revaluation is to be taken as 5% per annum compound.
        
            (2)  Where the Member's pension, being an alternative
                 to Short Service Benefit, becomes payable before or after
                 Normal Retiring Date, the value of that pension must, to the
                 reasonable satisfaction of the Trustees, be at least equal to




                                     40
<PAGE>   41

                 the value of the Short Service Benefit, plus the revaluation
                 to Normal Retiring Date that the deferred pension would have
                 attracted in accordance with Chapter II of Part IV of the Act
                 had it been provided by the Scheme at Normal Retiring Date,
                 and the revaluation of GMP referred to in (1) above.

            (3)  Where commutation of the whole of a Member's deferred pension 
                 is taking place at Normal Retiring Date (or on the winding up
                 of the Scheme if earlier), the Member's pension in excess of
                 GMP must be revalued up to Normal Retiring Date in accordance
                 with Chapter II of Part IV of the Act and the GMP revalued in
                 accordance with (1) above.
        
            (4)  In any event, the Trustees must be satisfied that the basis of
                 commutation is reasonable.  The basis must be certified as 
                 reasonable by an Actuary or be in accordance with commutation 
                 factors agreed with the PSO as suitable for the Scheme.

13.   SECURING GMPS

      GMPs may be secured through the Scheme provided it has been established
      under an irrevocable trust subject to the laws of any part of the United
      Kingdom.  Otherwise, a GMP must be secured by means of an insurance
      policy or annuity contract with an Insurer.

14.   WINDING-UP OF THE SCHEME

      14.1 PRIORITIES ON WINDING-UP.  If the Scheme winds-up for any
           reason, priority must be given, over any other liability to provide
           benefits, to any benefit which falls within any one or more of the
           following:-

           (1)  Pensions and other benefits in respect of which entitlement to 
                payment has already arisen;

           (2)  GMPs and accrued rights to GMPs;




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<PAGE>   42


           (3)  State scheme premiums;

           (4)  Equivalent pension benefits within the meaning of
                the National Insurance Act 1965.

           [See Section C for further priorities which may be added.]

      14.2 ORDER OF PRIORITIES.  The Trustees and the principal employer
           participating in the Scheme may elsewhere in the provisions of the
           Scheme specify an order of priorities amongst the items listed in
           14.1 above, but the order of priorities shall not give any liability
           to provide benefits which are not listed in 14.1 above priority
           equal to or exceeding the priority given to any item which is listed
           there.

      14.3 VOLUNTARY CONTRIBUTIONS. [Optional - see Section C]

15.   SCHEME CEASES TO BE A CONTRACTED-OUT SALARY RELATED SCHEME

      If the Scheme ceases to be a contracted-out salary related scheme, the
      Trustees must seek the approval of the Occupational Pensions Board to any
      proposed arrangement for securing GMPs.  If it is decided to buy Members
      back into the State Earnings Related Pension Scheme (SERPS), then accrued
      rights premiums or pensioner's rights premiums must be paid to the
      Secretary of State for Social Security in the manner required by
      regulations made under the Act.  Once these premiums have been paid, the
      GMPs will be extinguished.  The other benefits of the Members, Widows or
      Widowers concerned under the Scheme shall be reduced by the amount of the
      GMP accrued at the date the Scheme ceased to be contracted-out, increased
      to State Pensionable Age (or the Member's death, if earlier) by Fixed
      Rate Revaluation or Section 148 Revaluation.

16.   SUSPENSION OF GMP [Optional - see Section C]




                                     42
<PAGE>   43

17. FORFEITURE OF GMP [Optional - see Section C]

18. CONTRIBUTIONS EQUIVALENT PREMIUMS [Optional - see Section C]

















                                     43
<PAGE>   44


                                   SECTION B

                     THE EMPLOYER'S COMPULSORY ALTERNATIVES

THE EMPLOYER MUST SELECT ONE (ONLY) OF EACH SET OF COMPULSORY ALTERNATIVES, AND
INDICATE ITS CHOICE BY TICKING THE APPROPRIATE BOX ON THE CERTIFICATE.

RULE 5.4

ALTERNATIVE A: 5.4  The pension shall be paid for life to any Widow.

ALTERNATIVE B: 5.4  The pension shall be paid for life to any Widow who is
                    eligible for payment of a State benefit as described in
                    section 17(5) of the Act.

ALTERNATIVE C: 5.4  The pension shall be payable to any Widow.  It shall cease
                    if the Widow remarries before her 60th birthday, but
                    otherwise it shall be payable for life.

ALTERNATIVE D: 5.4  The pension shall be payable to any Widow who is eligible
                    for payment of a State benefit as described in section
                    17(5) of the Act.  It shall cease if she remarries before
                    her 60th birthday, but otherwise it shall be payable for
                    life.

ALTERNATIVE E: 5.4  The pension shall be payable to any Widow who is   eligible
                    for payment of a State benefit as described in section
                    17(5) of the Act.  It shall cease when the Widow ceases to
                    be entitled to receive payment of those State benefits.





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<PAGE>   45







RULE 5.6

ALTERNATIVE A: 5.6  The pension shall be paid for life to any Widower.

ALTERNATIVE B: 5.6  The pension shall be paid for life to any Widower who is
                    eligible for payment of a GMP under Regulation 33B of the
                    Occupational Pension Schemes (Contracting-out)  Regulations
                    1984.

ALTERNATIVE C: 5.6  The pension shall be payable to any Widower.  It shall
                    cease if the Widower remarries before his 65th birthday,
                    but otherwise it shall be payable for life.

ALTERNATIVE D: 5.6  The pension shall be payable to any Widower who is eligible
                    for payment of a GMP under Regulation 33B of the
                    Occupational Pension Schemes (Contracting-out) Regulations
                    1984.  It shall cease if the Widower remarries before his
                    65th birthday, but otherwise it shall be payable for life.

ALTERNATIVE E: 5.6  The pension shall be payable to any Widower who is eligible
                    for payment of a GMP under Regulation 33B of the
                    Occupational Pension Schemes (Contracting-out) Regulations
                    1984.  It shall cease when the Widower ceases to be
                    entitled to receive payment of that GMP under Regulation
                    33C of those Regulations.




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<PAGE>   46




                                   SECTION C

                        THE EMPLOYER'S VOLUNTARY OPTIONS

THESE VOLUNTARY OPTIONS WILL APPLY ONLY IF THE EMPLOYER INDICATES THAT THEY ARE
TO APPLY BY TICKING THE APPROPRIATE BOX ON THE CERTIFICATE.  THE EMPLOYER
SHOULD INCLUDE ONLY THOSE OPTIONS OF RULE 14.1 WHICH HE WISHES TO APPLY TO THE
SCHEME.

RULE 14.3 IS OPTIONAL AND MAY BE OMITTED ENTIRELY.

RULES 16, 17 AND 18 ARE OPTIONAL.  THEY SHOULD BE INCLUDED ONLY IF THE EMPLOYER
WISHES ONE OR MORE OF THE OPTIONS TO APPLY TO THE SCHEME, BUT MAY BE OMITTED
ENTIRELY.

RULE 14.1

OPTION A: ( )  in the case of a serving Member who has attained Normal Retiring
               Date before the winding-up began, the benefits to which the
               Member would have been entitled if the Member had retired on the
               day the winding-up began.

OPTION B: ( )  benefits attributable to the Member's service before the Scheme
               became a contracted-out scheme.

OPTION C: ( )  benefits attributable to the Member's service before the Scheme
               became a contracted-out scheme and calculated in accordance with
               the provisions of the Scheme in force and relevant earnings at
               that time.

OPTION D: ( )  benefits to which the widow or widower or any dependant of a
               Member to whom 14.1(1) applies will be entitled on the Member's
               death.




                                     46
<PAGE>   47

OPTION E: ( )  benefits to which any dependant of a deceased Member will be
               entitled on the death of any widow or widower or dependant of
               that Member.

OPTION F: ( )  benefits to which the widow or widower or any dependant of a
               serving Member who has attained Normal Retiring Date before the
               winding-up began will become entitled on the death of the
               Member.

OPTION G: ( )  benefits resulting from transfer credits.


RULE 14.3

14.3 VOLUNTARY CONTRIBUTIONS. Where Members' voluntary contributions to the
     Scheme are being used to provide benefits equivalent on a money purchase
     basis to the voluntary contributions paid, and where there are separately
     identifiable assets attributable to those voluntary contributions within
     the Scheme, 14.1 above shall not apply to those separately identifiable
     assets.  That part of those assets which is attributable to the voluntary
     contributions of a Member shall be used to provide benefits for, or in
     respect of, that Member of the types specified in the other provisions of
     the Scheme.  No regular payments may be made by the employer to those
     separately identified assets unless they are used solely for the purpose
     of meeting administrative expenses.





                                     47
<PAGE>   48

RULE 16

16.  SUSPENSION OF GMP

     Payment of a GMP may be suspended during any period when:-

     OPTION A:

     the person receiving the GMP is unable to act (by reason of mental
     disorder or otherwise) but the amount of the GMP must either be paid or
     applied for the maintenance of the recipient or his dependants, or paid
     to the recipient when that recipient is again able to act, or paid to the
     recipient's estate after that recipient's death.

     OPTION B:

     the recipient of the GMP is in prison or detained in legal custody but
     the amount of the GMP must then be paid or applied for the maintenance of
     such one or more of the recipient's dependants as the Trustees shall
     determine.
     
     OPTION C:

     the Member is receiving the GMP but is then re-employed in an employment
     to which the Scheme relates.  The GMP must then be increased under Rule
     7.1 above during the period of suspension.
     




                                     48
<PAGE>   49


RULE 17

17.  FORFEITURE OF GMP

     OPTION A:

     Any instalment of a GMP may be forfeited if it is not paid within 6 years
     of the date on which the instalment became due and the Trustees do not
     know the whereabouts of the recipient.
     
     OPTION B:

     A GMP may be forfeited if the person entitled to the GMP has been
     convicted of one or more offences under the Official Secrets Acts 1911 to
     1989, for which the recipient has been sentenced to a term or consecutive
     terms of imprisonment totalling at least 10 years, or of an offence of
     treason.
     
RULE 18

18.  CONTRIBUTIONS EQUIVALENT PREMIUMS

     18.1 A contributions equivalent premium shall be paid, subject to
          18.2 below, in respect of a Member who ceases to be in Contracted-out 
          Employment before whichever is the earlier of the Member's Normal 
          Retiring Date and the end of the tax year preceding that in which the
          Member will reach State Pensionable Age with less than 2 years'
          Qualifying Service and less than 2 years' Contracted-out  Employment. 
          A contributions equivalent premium shall not be paid where the
          Member's accrued rights include rights transferred from a personal
          pension, nor where the Member is a woman who  dies in contracted-out  
          employment in respect of Widower's GMP.
        


                                     49
<PAGE>   50


            Payment of the contributions equivalent premium extinguishes the
            Member's accrued rights to GMPs under the Scheme.  Therefore, where
            the premium is paid, any refund of contributions to the Member or
            any transfer payment from the Scheme in respect of a Member shall
            be reduced by the certified amount (as defined in the Act) in
            relation to that premium and any pension benefit under the Scheme
            for the Member or the Member's Widow or Widower shall be reduced so
            as to allow for the fact that their accrued rights to GMPs have
            been extinguished.

      18.2  The premium shall not be payable if:-

            OPTION A:

            its amount is less than pounds sterling 17 (or such greater amount
            as is specified in regulations made under the Act).

            OPTION B:

            the Member's accrued rights to GMPs are transferred to another
            scheme, policy or contract in accordance with Rule 10 above.

            OPTION C:

            the Member has become entitled to an immediate or a deferred
            pension under the Scheme on ceasing to be in Contracted-out
            Employment.




                                     50
<PAGE>   51



                                   SECTION D

         {THIS CERTIFICATE FORMS PART OF THE MODEL RULES DOCUMENTATION}

                          OCCUPATIONAL PENSIONS BOARD

                     CONTRACTED-OUT SALARY RELATED SCHEMES

CERTIFICATE TO CONFIRM WHICH PARTS OF SECTIONS B AND C HAVE BEEN INCORPORATED
INTO SECTION A OF THE MODEL RULES


I certify that the Comshare Retirement and Death Benefits Plan has adopted with
effect from the date of the deed to which this certificate is appended as part
of the documentation of the scheme an Overriding Appendix of GMP Model Rules,
coded OPB/SR/1995, which incorporates the whole of Section A of Appendix 10 of
Memorandum No 77 and the parts of Section B and C specified below.

               SECTION B - THE EMPLOYER'S COMPULSORY ALTERNATIVES

(Tick the appropriate box to indicate which Compulsory Alternative is adopted.
ONE ONLY of each set of Compulsory Alternatives must be adopted.)

RULE 5.4:-


Alternative A  (.....X.......)
Alternative B  (.............)
Alternative C  (.............)
Alternative D  (.............)
Alternative E  (.............)





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<PAGE>   52


RULE 5.6:-

Alternative A  (.....X.......)
Alternative B  (.............)
Alternative C  (.............)
Alternative D  (.............)
Alternative E  (.............)



SECTION C - THE EMPLOYER'S VOLUNTARY OPTIONS

(Tick the appropriate box only if the Option is to apply.)

RULE 14.1:-


Option A        (.....X.......)
Option B        (.............)
Option C        (.............)
Option D        (.....X.......)
Option E        (.....X.......)
Option F        (.....X.......)
Option G        (.............)

RULE 14.3:-

Applies         (.....X.......)
Does not Apply  (.............)

RULE 16:-

Option A        (.....X.......)
Option B        (.....X.......)
Option C        (.....X.......)





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<PAGE>   53

RULE 17:-

Option A        (......X.......)
Option B        (......X.......)

RULE 18:-

Applies         (......X.......)
Does not Apply  (..............)



RULE 18.2 (ONLY IF RULE 18 APPLIES TO THE SCHEME):-


Option A        (......X.......)
Option B        (......X.......)
Option C        (......X.......)



Signature    /s/ B. M. Cole         (The Certificate must be signed by either:-
          --------------------      (i)    the administrator of the scheme; or
                                    (ii)   a director of the insurance company
                                           concerned; or
Name  Miss B. M. Cole               (iii)  an employee authorised by the 
     -------------------------             insurance company to sign such a 
                                           certificate on its behalf; or
                                     (iv)  a person who is recognised by a
                                           self-regulating organisation under
                                           the Financial Services Act 1986 or
                                           regulated by a professional body
                                           under that Act; or a person who is
                                           authorised by a consultancy which is
                                           so recognised or regulated.)






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