<PAGE>   1
                                                                    EXHIBIT 99.2



                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)


<PAGE>   2

                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)

                               TABLE OF CONTENTS

                  Article I.  The Plan


             1.1  Establishment and Amendment of the Plan          1
             1.2  Applicability of the Plan                        1
             1.3  Purpose and Type of Plan                         2

                  Article II.  Definitions

             2.1  Definitions                                      3
             2.2  Construction                                    15

                  Article III.  Participation and Service

             3.1  Eligibility Requirements                        16
             3.2  Eligibility Upon Merger or Reemployment         16
             3.3  Collective Bargaining Agency                    17
             3.4  Applications                                    17
             3.5  Years of Service                                18
             3.6  Break in Service Year                           19
             3.7  Hours of Employment                             20
             3.8  Employment by Related Entities                  22
             3.9  Leased Employees                                22
             
                  Article IV.  Contributions

             4.1  Employee Allotments                             24
             4.2  Employer Savings Plan Contributions             27
             4.3  Employer ESOP Contributions                     28
             4.4  Additional Employer Contributions               29
             4.5  Rollover Contributions                          30
             4.6  Transfers from the MichCon Investment and
                   Stock Ownership Plan                           33
             4.7  Transfers from the MichCon Employee Stock
                   Ownership Plan                                 34
             4.8  Limitations on Salary Reduction Allotments      35
             4.9  Distribution of Excess Deferrals                38
            4.10  Distribution or Recharacterization of Excess
                   Contributions                                  39
            4.11  Limitations on Voluntary Deduction Allotments
                   and Employer Contributions                     42
            4.12  Disposition of Excess Aggregate Contributions   44
            4.13  Statutory (Code Section 415) Limitations on
                   Allocations to Accounts                        48




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<PAGE>   3
                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)

                               TABLE OF CONTENTS
                                  (Continued)

                  Article V.  Vesting in Accounts


             5.1  Employee Salary Reduction Accounts,
                    Employee Post-1986 Voluntary Deduction
                    Account, and Employee Pre-1987 Voluntary
                    Deduction Account                              53
             5.2  Employer Salary Reduction Account,               
                    Employer Voluntary Deduction Account,          
                    and ESOP Account                               53
                                                                   
                  Article VI.  Investment Provisions               
                                                                   
             6.1  Investment of Contributions and Allotments       54
             6.2  Change of Investment Direction                   54
             6.3  Transfers Between Investment Funds               54
                                                                   
                  Article VII.  Investment Funds                   
                                                                   
             7.1  Investment Funds                                 56
             7.2  Management of Investment Funds                   57
             7.3  Voting of MCN Stock                              57
             7.4  Tender Offers                                    58
             7.5  Named Fiduciary Status                           60
             7.6  Expenses of Funds                                60
             7.7  Primark Corporation Stock                        60
                                                                   
                  Article VIII.  Accounts and Records of the Plan  
                                                                   
             8.1  Committee to Maintain Accounts                   61
             8.2  Plan Accounting                                  61
             8.3  Valuation of Funds                               62
             8.4  Valuation of Savings Plan Account                62
             8.5  Valuation of ESOP Account                        62
             8.6  Valuation of Plan Account                        62
             8.7  Committee to Furnish Annual Statements of        
                    Value of Plan Accounts                         63
             8.8  Trust Agreement                                  63

                  Article IX.  Distributions, Withdrawals, and     
                  Loans                                            

             9.1  Distribution Upon Termination of                 
                    Employment Entitling Participant               
                    to Value of Plan Account                       64
                                                                               
             
             
             
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<PAGE>   4
                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)

                               TABLE OF CONTENTS
                                  (Continued)


            9.2  Distribution Upon Termination of
                   Employment Under Circumstances
                   Resulting in Forfeiture of Employer
                   Contributions                                  64
            9.3  Certain Distributions from Participant
                   Accounts                                       65
            9.4  In-Service Withdrawals--General                  67
            9.5  Withdrawal of Voluntary Deduction Allotments     67
            9.6  Hardship Withdrawal of Salary Reduction
                   Allotments                                     68
            9.7  Time of Distributions                            70
            9.8  Distributions of Stock                           74
            9.9  Distributions from Fixed Income Fund             75
           9.10  Loans                                            78
           9.11  Definition of Allotments and Employer
                   Contributions                                  82
           9.12  Spousal Consent to Payment                       82
           9.13  Distributions Pursuant to a Qualified
                   Domestic Relations Order                       82
           9.14  Direct Rollovers of Eligible Distributions       83

                 Article X.  Administration

           10.1  The Savings and Stock Ownership Plan Committee   86
           10.2  Notice to Employees                              89
           10.3  Notices to Employers or Committee                89
           10.4  Participants' Acceptance of the Provisions
                   of the Plan                                    90
           10.5  Audit of Plan Records                            90
           10.6  Claims Procedure                                 90
           10.7  Effect of a Mistake                              91

                 Article XI.  Amendment and Termination

           11.1  Amendment                                        92
           11.2  Withdrawal                                       92
           11.3  Termination                                      92
           11.4  Allocation of Funds Between Employers            93
           11.5  Trust to be Applied Exclusively for
                   Participants and Their Beneficiaries           93


                                     -iii-








<PAGE>   5
                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)

                               TABLE OF CONTENTS
                                  (Continued)

                    Article XII.  Participation by Affiliated
                    Companies


              12.1  Adoption of the Plan                        95
              12.2  Withdrawal from the Plan                    95
              12.3  Special Provisions Relating to Withdrawal
                     by MCN Computer Services, Inc.             95
              12.4  Company as Agent for Employers              97

                    Article XIII.  Top-Heavy Plan Rules

              13.1  Application of Top-Heavy Plan Rules         98
              13.2  Special Definitions                         98
              13.3  Determination of Top-Heavy Status          100
              13.4  Superseding Rules                          104
              13.5  Participants in More Than One Top-Heavy
                     Plan of the Employer                      106
              13.6  Changes in Applicable Vesting Schedule     107

                    Article XIV.  Special Provisions Relating to
                    the ESOP

              14.1  Establishment of ESOP                      109
              14.2  ESOP Account                               109
              14.3  Discrimination Testing                     109
              14.4  Loans                                      110
              14.5  Diversification                            113
              14.6  Put Option                                 113
              14.7  Purchase of MCN Stock                      114

                    Article XV.  Miscellaneous

              15.1  Beneficiary Designation                    115
              15.2  Incompetency                               116
              15.3  Expenses                                   117
              15.4  Nonassignability                           117
              15.5  Employment Noncontractual                  117
              15.6  Merger or Consolidation with Another Plan  117
              15.7  Continuance by a Successor                 118
              15.8  Elimination of Certain Provisions          119




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<PAGE>   6
                                    MICHCON
                        SAVINGS AND STOCK OWNERSHIP PLAN
           (As Amended and Restated Effective as of January 1, 1989)


                              Article I.  The Plan

     1.1 Establishment and Amendment of the Plan.  Michigan Consolidated Gas
Company which is also known as MichCon (hereinafter referred to as the
"Company") presently maintains a savings and stock ownership plan for the
benefit of its Eligible Employees and the Eligible Employees of its
participating Affiliated Companies.  The plan was last restated effective as of
April 1, 1989, and was amended from time to time thereafter.

The plan as previously restated established the MichCon Employee Stock Ownership
Plan for Non-Union Employees ("ESOP") and incorporated the ESOP into the MichCon
Savings Plan to form the MichCon Savings and Stock Ownership Plan.

The plan is hereby further amended and completely restated as set forth herein
effective as of January 1, 1989, except as otherwise provided herein or required
by law, and shall continue to be known as the "MichCon Savings and Stock
Ownership Plan" (the "Plan").  The ESOP provisions of the Plan shall be
effective as of April 1, 1989.

     1.2 Applicability of the Plan.  Except as otherwise specified herein or
required by law, the provisions of the Plan as amended and restated herein
effective as of January 1, 1989, shall be applicable only with respect to
Eligible Employees of an Employer in current employment on or after January 1,
1989, and their beneficiaries.

Any person who was covered under the Plan as in effect prior to January 1, 1989,
and whose employment terminated under the Plan



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<PAGE>   7


prior to January 1, 1989, shall continue to have his rights to receive benefits
determined under the provisions of the Plan in effect when his employment
relationship so terminated.

     1.3 Purpose and Type of Plan.  The purpose of the Plan is to provide a
convenient way for Participants to save on a regular and long-term basis for
their retirement income needs; to recognize the contribution made to the
Employer's successful operation by its employees and to reward such contribution
for those employees who qualify as participants under the terms of the Plan; and
to facilitate ownership of MCN Stock by participating Eligible Employees.

The non-ESOP portion of the Plan is intended to qualify as a profit-sharing plan
and the ESOP portion of the Plan is intended to qualify as a stock bonus and an
employee stock ownership plan for purposes of Code sections 401(a), 402, 412,
417, 4975, and related provisions.




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                          Article II.  Definitions

     2.1   Definitions.  Whenever used in the Plan, the following words and
phrases shall have the respective meanings stated below unless a different
meaning is plainly required by the context.
      (a)  "Accounting Period" means a period of one calendar month
           except that the first accounting period shall commence with the date
           on which the Plan first becomes effective with respect to any
           Employer and end on the last day of the calendar month in which such
           effective date occurs.
      (b)  "Actual Deferral Percentage" means the ratio (expressed as a
           percentage) of the Elective Deferrals of an Employee who is eligible
           to participate in the Plan for a Plan Year to the Compensation of
           that Employee for such Plan Year.
      (c)  "Affiliated Company" means--
           (1)   any corporation other than the Company, i.e., either a
                 subsidiary corporation or an affiliated or associated
                 corporation of the Company, which together with the Company is
                 a member of a "controlled group" of corporations (as defined in
                 Code section 414(b));
           (2)   any organization which together with the Company is under
                 "common control" (as defined in Code section 414(c));
           (3)   any organization which together with the Company is an
                 "affiliated service group" (as defined in Code section 414(m));
                 or
           (4)   any other entity required to be aggregated with the Company
                 pursuant to Regulations under Code section 414(o).
      (d)  "Anniversary Date" means with respect to each Employee, the
            anniversary each year of the first day of the first
            Accounting Period coincident with or next following the Employee's
            first Hour of Employment.  If an Employee whose employment was
            terminated is reemployed but prior


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           to his reemployment he incurs a Break in Service Year or following
           his reemployment he incurs a Break in Service Year before completing
           a Year of Service, his Anniversary Date shall be based upon his first
           Hour of Employment coincident with or next following his date of
           reemployment; otherwise, his Anniversary Date shall not be changed.
      (e)  "Annual Addition" means the amount allocated to a
           Participant's account as such term is defined in section 4.13(a).
      (f)  "Average Actual Deferral Percentage" means the average
           (expressed as a percentage) of the Actual Deferral Percentages of
           the Employees in a group who are eligible to participate in the Plan
           for a Plan Year.
      (g)  "Average Contribution Percentage" means the average
           (expressed as a percentage) of the Contribution Percentages of the
           Employees in a group who are eligible to participate in the Plan for
           a Plan Year.
      (h)  "Break in Service Year" means a 12-month period described in
           section 3.6.
      (i)  "Code" means the Internal Revenue Code of 1986, as amended.
      (j)  "Committee" means the committee appointed pursuant to section
           10.1 to administer the Plan.
      (k)  "Company" means Michigan Consolidated Gas Company.
      (l)  "Compensation" means a Participant's pay, determined as
           follows:
           (1)  For all purposes of the Plan, except as otherwise specified in
                (2) or (3) below or required by the context, Compensation means
                Eligible Compensation.
           (2)  For purposes of satisfying the limits on contributions described
                in sections 4.8 and 4.11 (ADP and ACP tests) and applying the
                limits of section 415 of the Code as described in section 4.13,
                Compensation includes all of the items listed below as
                includible (to the extent



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<PAGE>   10

                  applicable) and excludes all of the items listed below as
                  excludable (to the extent applicable) on a Plan Year basis:
                  (A) Includible.
                      (i)   The Employee's wages, salaries, fees, for
                            professional services, and other amounts received
                            (without regard to whether or not an amount is paid
                            in cash) for personal services actually rendered in
                            the course of employment with the Employer and any
                            Affiliates to the extent that the amounts are
                            includible in gross income including, but not being
                            limited to, commissions paid salesmen, compensation
                            for services on the basis of a percentage of
                            profits, commissions on insurance premiums, tips,
                            bonuses, fringe benefits, and reimbursements or
                            other expense allowances under a nonaccountable plan
                            (as described in Treasury regulation section
                            1.62-2(c));
                      (ii)  Amounts described in Code sections 104(a)(3),
                            105(a), and 105(h), but only to the extent that
                            these amounts are includible in the Employee's gross
                            income;
                      (iii) Amounts paid or reimbursed by the Employer or any
                            Affiliate for moving expenses incurred by the
                            Employee, but only to the extent that at the time of
                            the payment it is reasonable to believe that these
                            amounts are not deductible by the Employee under
                            Code section 217;
                      (iv)  The value of a nonqualified stock option granted to
                            an Employee by the Employer or any Affiliate, but
                            only to the extent



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<PAGE>   11

                            that the value of the option is includible in the
                            Employee's gross income for the taxable year in
                            which it is granted; and
                      (v)   The amount includible in an Employee's gross income
                            upon making the election described in Code section
                            83(b).
                      Compensation under clause (i) includes foreign earned
                      income as defined in Code section 911(b), whether or not
                      excludable from gross income under Code section 911.

                      Compensation under clause (i) is to be determined without
                      regard to the exclusions from gross income in Code
                      sections 931 and 933.

                 (B)  Excludable.
                      (i)   Contributions made by the Employer or any Affiliate
                            to a plan of deferred compensation to the extent
                            that, before the application of the Code section 415
                            limitations to that plan, the contributions are not
                            includible in the Employee's gross income for the
                            taxable year in which they are contributed;
                      (ii)  Contributions made by the Employer or any Affiliate
                            on an Employee's behalf to a simplified employee
                            pension described in Code section 408(k) (such
                            contributions are not considered as compensation for
                            the taxable year in which contributed);
                      (iii) Distributions from a plan of deferred compensation,
                            regardless of whether such amounts are includible in
                            the Employee's gross income when distributed, except
                            that amounts received by an Employee



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<PAGE>   12



                            pursuant to an unfunded, nonqualified plan are
                            permitted to be considered as Compensation for Code
                            section 415 purposes in the year in which the
                            amounts are includible in the Employee's gross
                            income;
                      (iv)  Amounts realized from the exercise of a nonqualified
                            stock option, or when restricted stock (or property)
                            held by an Employee either becomes freely
                            transferable or is no longer subject to a
                            substantial risk of forfeiture within the meaning of
                            Code section 83 and regulations thereunder;
                      (v)   Amounts realized from the sale, exchange, or other
                            disposition of stock acquired under a qualified
                            stock option; and
                      (vi)  Other amounts which receive special tax benefits,
                            such as premiums for group-term life insurance (but
                            only to the extent that the premiums are not
                            includible in the Employee's gross income).

            (3)  For purposes of determining whether an individual
                 is a Highly Compensated Employee, Compensation means an
                 Employee's Compensation as defined in paragraph (2) of this
                 section 2.1(l) but without regard to Code sections 125,
                 402(a)(8), and 402(h)(1)(B) (i.e., with the addition of
                 elective deferrals pursuant to a cafeteria plan, a
                 cash-or-deferred arrangement, or a simplified employee
                 pension).

            For Plan Years beginning on or after January 1, 1989 and prior to
            January 1, 1994, the Compensation of each Employee that may be
            taken into account under the Plan, except for purposes of section
            4.13 (Code section 415



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<PAGE>   13


           limits), shall not exceed the first $200,000 of an Employee's
           Compensation (as adjusted by the Secretary of the Treasury under Code
           section 415(d)).  For Plan Years begnning on or after January 1,
           1994, the Compensation of each Employee that may be taken into
           account under the Plan, except for purposes of section 4.11, shall
           not exceed the first $150,000 of an Employee's Compensation (as
           adjusted pursuant to Code section 401(a)(17)).  For purposes of the
           preceding two sentences, if an Employee is a 5-percent owner of the
           Employer or one of the ten Highly Compensated Employees paid the
           greatest Compensation during the year, then any Compensation paid to
           the spouse of such Employee or to any lineal descendants of such
           Employee who have not attained age 19 before the close of the year
           (and any applicable contribution on behalf of any such individual)
           shall be treated as if it were paid to (or on behalf of) such
           Employee.
      (m)  "Compensation Rate" means the amount of an Employee's Eligible
           Compensation per pay period determined under uniform rules
           established by the Committee and before recognition of any Salary
           Reduction allotment or cafeteria plan election.
      (n)  "Contribution Percentage" means
           (1)   with respect to the non-ESOP portion of the Plan, the ratio
                 (expressed as a percentage) of the sum of Voluntary Deduction
                 allotments and the Employer contributions under section 4.2
                 made on behalf of an Employee who is eligible to participate
                 for a Plan Year to the Compensation of the Employee for such
                 Plan Year; provided, however, that in accordance with Code
                 section 401(m), the Company may elect to take into account
                 Elective Deferrals in computing such Contribution Percentage;
                 and
           (2)   with respect to the ESOP portion of the Plan, the ratio
                 (expressed as a percentage) of the sum of the Employer
                 contributions under section 4.3(a)



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<PAGE>   14

                 made on behalf of an Employee who is eligible to participate
                 and the value of the shares allocated under section 14.4(d) to
                 the ESOP Account of the Employee for a Plan Year to the
                 Compensation of the Employee for such Plan Year.
      (o)   "Disability Retirement Date" means the date a Participant--
            (1)  becomes eligible to receive benefits under a
                 long-term disability plan maintained by the Employer, or
            (2)  is determined by the Committee to be totally and
                 permanently disabled.
            In determining whether a Participant is totally and permanently
            disabled, the Committee may, in its discretion, rely on the opinion
            of a physician selected by the Committee to assist it in making
            such a determination.
      (p)   "Early Retirement Date" means the first day of any month
            prior to a Participant's Normal Retirement Date on which he
            terminates his employment by giving at least 60 days' written notice
            to the Committee of his intention to retire after he has attained
            age 55 and the sum of his attained age and the number of his full
            Years of Service is at least 70.
      (q)   "Elective Deferrals" means Salary Reduction allotments under
            section 4.1(a) and contributions under other plans maintained by the
            Company or an Affiliated Company that constitute elective deferrals
            within the meaning of Code section 402(g)(3).
       (r)  "Eligible Compensation" means the regular basic salary or wage paid
            to an Employee by the Employer before any payroll deduction for
            taxes or any other purpose, and before any Salary Reduction
            allotment or cafeteria plan election, but excluding bonuses, awards,
            shift differentials, deferred compensation, severance payments,
            differential payments made by reason of the Employee's entry into
            Military Service, all amounts



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<PAGE>   15


            paid for work in excess of 40 hours in any one week, all overtime or
            other premium paid for work in excess of a maximum number of hours
            in any one day, for work on holidays or for any other reason,
            payments for so-called fringe benefits such as Employer
            contributions to this Plan or any pension or retirement plan,
            increased wages or salary resulting from temporary promotion,
            upgrading or transfer, of whatever duration, to a higher paid job or
            classification, and any other premium, auxiliary, or special pay of
            any sort whatsoever.

            January 1, 1994, the Eligible Compensation of an Employee for
            purposes of the Plan shall not exceed $200,000; provided, however,
            that such limit shall be adjusted as provided in Code section
            415(d).  For Plan Years beginning on or after January 1, 1994, the
            Eligible Compensation of each Employee that may be taken into
            account under the Plan, except for purposes of section 4.11, shall
            not exceed the first $150,000 of an Employee's Compensation (as
            adjusted pursuant to Code section 401(a)(17)).  For purposes of the
            preceding two sentences, if an Employee is a 5-percent owner of the
            Employer or one of the ten Highly Compensated Employees paid the
            greatest Compensation during the year, any Compensation paid to the
            spouse of such Employee or to any lineal descendants of such
            Employee who have not attained age 19 before the close of the year
            (and any applicable contribution on behalf of any such individual)
            shall be treated as if it were paid to (or on behalf of) such
            Employee.
       (s)  "Eligible Employee" means an Employee of an Employer, other than a
            "leased employee" described in section 3.9 or an Employee covered by
            a collective bargaining agreement between Employee representatives
            and the Employer.



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<PAGE>   16

       (t)  "Employee" means an individual who is an employee of the Company or
            an Affiliated Company.

       (u)  "Employee Post-1986 Voluntary Deduction Account" means an Employee's
            Voluntary Deduction allotments after December 31, 1986, and
            investment gains and losses therefrom.

       (v)  "Employee Pre-1987 Voluntary Deduction Account" means an Employee's
            Voluntary Deduction allotments before January 1, 1987, and
            investment gains and losses therefrom.

       (w)  "Employee Salary Reduction Account" means an Employee's Salary
            Reduction allotments, and investment gains and losses therefrom.

       (x)  "Employer" means the Company and any Affiliated Company which has
            adopted the Plan with the consent of the Company and in the manner
            prescribed in section 12.1 and any successor corporation which shall
            adopt the Plan pursuant to section 15.7.  If any such corporation
            shall withdraw from participation in the Plan in accordance with
            section 12.2, the term Employer shall not thereafter include such
            corporation.

       (y)  "Employer Salary Reduction Account" means the Employer contributions
            to the Salary Reduction Account of an Employee pursuant to section
            4.2, and investment gains and losses therefrom.

       (z)  "Employer Voluntary Deduction Account" means the Employer
            contributions to the Voluntary Deduction Account of an Employee
            pursuant to section 4.2, and investment gains and losses therefrom.

      (aa)  "ERISA" means the Employee Retirement Income Security Act of 1974,
            as amended.

      (bb)  "ESOP" means the employee stock ownership plan established pursuant
            to section 14.1.

      (cc)  "ESOP Account" means the account established and maintained on
            behalf of each Participant in accordance with sections 8.1(c) and
            (d) and 14.2.



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<PAGE>   17

      (dd) "Excess Aggregate Contributions" means the amount described in
            section 4.12(a).
      (ee) "Excess Contributions" means the amount described in section 4.10(a).
      (ff) "Excess Deferrals" means the portion of Elective Deferrals for a
            calendar year, if any, described in section 4.9.
      (gg) "Family Member" means an individual described as a family member in
            Code section 414(q)(6).
      (hh) "Highly Compensated Employee" means, with respect to any Plan Year,
            any Employee who at any time during the preceding Plan Year (or such
            other period as the Company may elect pursuant to Treasury
            regulations)--
            (1)  received Compensation (as defined in section 2.1(l)(3) of the
                 Plan) from the Employer and all Affiliates in excess of
                 $75,000,
            (2)  received Compensation (as defined in section 2.1(l)(3) of the
                 Plan) from the Employer and all Affiliates in excess of $50,000
                 and was in the top-paid 20 percent of Employees,
            (3)  was an officer who received Compensation (as defined in section
                 2.1(l)(3) of the Plan) from the Employer and all Affiliates in
                 excess of the amount in effect under Code section 415(b)(1)(A)
                 for the preceding Plan Year, or
            (4)  was a 5-percent owner.
            Unless the Company makes the "calendar year calculation election"
            under Treasury regulations, Highly Compensated Employee also means,
            with respect to any Plan Year, any Employee who, at any time during
            that Plan Year, met the descriptions contained in paragraph (1),
            (2), or (3) and was among the top-paid 100 Employees or any Employee
            who was a 5-percent owner.

            A Family Member of a Highly Compensated Employee and a former
            employee shall be treated as a Highly



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<PAGE>   18

            Compensated Employee to the extent required by sections 414(q)(6)
            and (9) of the Code and the regulations thereunder.

            The dollar limits described in paragraphs (1), (2), and (3) will be
            adjusted to reflect increases in the cost of living, in the manner
            and at the times prescribed by the Secretary of the Treasury.
       (ii) "Hour of Employment" means an hour for which an individual receives
            credit pursuant to section 3.7.
       (jj) "MCN Stock" means common stock of MCN Corporation.
       (kk) "Military Service" means service--
            (1)  on active duty, in time of national or local emergency, in the
                 armed forces of the United States or of any State thereof,
            (2)  in the armed forces of the United States or of any State
                 thereof under any compulsory service law, or
            (3)  in the armed forces of the United States or any of its allies
                 in time of war in which the United States is engaged.
       (ll) "Nonhighly Compensated Employee" means an Employee of the Employer
            who is neither a Highly Compensated Employee nor a Member of a
            Highly Compensated Employee who is a 5-percent owner of the Employer
            or one of the ten Highly Compensated Employees paid the greatest
            Compensation during the year.
       (mm) "Normal Retirement Date" means the Participant's sixty-fifth
            birthday, if such birthday falls on the first day of the month;
            otherwise, the first day of the month next following the month in
            which such birthday occurs.
       (nn) "Participant" means an Employee who is participating in the Plan in
            accordance with its provisions.
       (oo) "Plan" means MichCon Savings and Stock Ownership Plan and any
            amendments thereto or restatements thereof from time to time
            adopted.
       (pp) "Plan Account" means the total value of an Employee's Savings Plan
            Account and ESOP Account.



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<PAGE>   19


        (qq) "Plan Year" means the calendar year.
        (rr) "Primark Corporation Stock" means common stock of Primark
             Corporation.
        (ss) "Regulations" means regulations issued by the Department of Labor
             construing Title I of ERISA or by the Internal Revenue Service
             construing the Code.
        (tt) "Salary Reduction" means an election by a Participant to have the
             Compensation Rate that would otherwise be payable reduced and
             contributed by the Employer to the Plan as a regular allotment on
             behalf of the Participant.
        (uu) "Salary Reduction Account" means an Employee's Salary Reduction
             allotments, related Employer matching contributions, and investment
             gains and losses therefrom.
        (vv) "Savings Plan Account" means the total value of an Employee's
             Salary Reduction Account and Voluntary Deduction Account.
        (ww) "Suspense Account" means the account used to reflect MCN Stock
             acquired with loan proceeds pursuant to section 14.4.
        (xx) "Trust" means the Trust created by agreement between the Employers
             and the Trustee, as from time to time amended.
        (yy) "Trust Agreement" means the agreement between the Employers and the
             Trustee referred to in section 8.8.
        (zz) "Trustee" means the Trustee hereinafter provided for in section 8.8
             or any successor Trustee.
       (aaa) "Valuation Date" means the last day of each Accounting Period on
             which the New York Stock Exchange shall be open for business.
       (bbb) "Vesting Requirement" means the requirement for vesting described
             in section 5.2.
       (ccc) "Voluntary Deduction" means an Employee's payroll deduction
             allotments other than Salary Reduction allotments.



                                      -14-



<PAGE>   20


       (ddd) "Voluntary Deduction Account" means an Employee's Voluntary
             Deduction allotments, related Employer matching contributions, and
             investment gains and losses therefrom.
       (eee) "Years of Service" means year(s) of employment of an Employee by an
             Employer or nonparticipating Affiliated Company as such term is
             defined in section 3.5.

     2.2 Construction.  Unless the context clearly requires otherwise--
        (a)  the masculine pronoun whenever used shall include the feminine, the
             singular shall include the plural, and vice versa, and
        (b)  headings of Articles and sections herein are included solely for
             convenience, and if there is any conflict between such headings and
             the text of the Plan, the text shall control.



                                      -15-



<PAGE>   21

                    Article III.  Participation and Service

      3.1  Eligibility Requirements.
      (a)  Each individual who was eligible to participate in the Plan
           on December 31, 1988, in accordance with the terms of the Plan in
           effect on said date shall continue to be eligible to participate,
           subject to the provisions of this Plan.  Each other Employee shall
           become eligible to participate on the first day of the first
           Accounting Period coincident with or next following the latest to
           occur of--
           (1)  the date he is employed as an Eligible Employee,
           (2)  the date on which he completes at least one year
                of eligibility service (as defined in section 3.1(b)), or
           (3)  the date on which he attains age 21;
           provided he is employed as an Eligible Employee on such date.
      (b)  For purposes of this Article III, a year of eligibility
           service shall mean the 12-month period beginning on the date of an
           Employee's first Hour of Employment, or the 12-month period
           beginning on an Employee's Anniversary Date during which he
           completes at least 1,000 Hours of Employment.

     3.2   Eligibility Upon Merger or Reemployment.  Any Employee who is a
Participant in any plan which is merged into this Plan shall become a
Participant in this Plan immediately upon the effective date of the merger. Such
an Employee shall be eligible to actively participate in this Plan in accordance
with section 3.4.

If a Participant's employment is terminated and he is thereafter reemployed
before incurring a Break in Service Year, he shall be eligible again to actively
participate in the Plan commencing with the first day of the first Accounting
Period coincident with or next following his date of reemployment. In the event
        


                                      -16-



<PAGE>   22

such Participant does incur a Break in Service Year, he shall be eligible again
to actively participate in the Plan commencing with the first day of the first
Accounting Period coincident with or immediately preceding the day on which he
is reemployed after he has again satisfied the eligibility requirement of
section 3.1(a).

     3.3 Collective Bargaining Agency.  If any Employee shall become a
Participant in the Plan and shall thereafter be represented by a collective
bargaining agency pursuant to a collective bargaining agreement between his
Employer and the collective bargaining agency representing such Employee, he
shall nevertheless continue to be eligible to actively participate in the Plan
until such time as the terms and conditions of his employment are governed by a
collective bargaining agreement between his Employer and the collective
bargaining agency representing such Employee, but shall be eligible thereafter
only if such agreement shall expressly so provide.

If such an Employee becomes eligible to participate in the Michigan Consolidated
Gas Company Union Employees' Investment Plan or any successor plan, his entire
Plan Account shall be transferred to such plan and the Employee shall no longer
be eligible to participate in this Plan.  Effective as of April 1, 1989, the
Participant's Plan Account shall be fully vested upon such transfer.

     3.4 Applications.  An Employee who is eligible to participate on the date
the Plan becomes effective with respect to his Employer may become a Participant
commencing with such effective date by filing a written application with his
Employer in the form prescribed by the Committee not later than 20 days after
such effective date.  Thereafter, an Eligible Employee may become a Participant
by filing a written application with his Employer in the form prescribed by the
Committee at least 20 days prior to the date upon which his participation is to
commence.




                                      -17-



<PAGE>   23

The Employee's application shall authorize the Employer to deduct allotments
from the Employee's Eligible Compensation in amounts specified by the Employee
pursuant to Article IV, and to have allotments made as a Salary Reduction
pursuant to Article IV.  The application shall evidence the Employee's
acceptance of and agreement to all of the provisions of the Plan.

     3.5 Years of Service.  An Employee shall be credited for Years of Service
for his period of employment with the Employer and each nonparticipating
Affiliated Company, determined as follows:
      (a)  An Employee shall receive credit, for purposes of vesting,
           for all Years of Service.  An Employee shall have one "Year of
           Service" for each 12-month period beginning on the date of the
           Employee's first Hour of Employment and on each subsequent
           Anniversary Date, during which the Employee completes 1,000 or more
           Hours of Employment.
      (b)  Years of Service shall not be interrupted--
           (1)  by any transfer of employment of an Employee between Affiliated
                Companies regardless of whether the Affiliated Company is an
                Employer hereunder; or
           (2)  during such period as an Employee is receiving credit for Hours
                of Employment under section 3.7.
      (c)  If an Employee is reemployed following a Break in Service Year, he
           shall be considered a new Employee for purposes of the Plan, except--
           (1)  If prior to such Break in Service Year he had a vested interest
                in his ESOP Account, Employer Salary Reduction Account, or
                Employer Voluntary Deduction Account, Years of Service he had
                prior to the Break in Service Year shall be reinstated after
                such Employee completes a Year of Service after such Break in
                Service Year.
           (2)  If section 3.5(c)(1) is not applicable, and if the Employee's
                number of consecutive Break in Service



                                      -18-



<PAGE>   24

                  Years does not equal or exceed the greater of five or the
                  number of Years of Service he had before incurring a Break in
                  Service Year, the Years of Service he had prior to such Break
                  in Service Years shall be reinstated after such Employee
                  completes a Year of Service after such Break in Service
                  Years.
      (d)  Notwithstanding the foregoing provisions, an Employee's Years
           of Service shall exclude any Years of Service completed before an
           Employee attains age 18.

     3.6 Break in Service Year.  "Break in Service Year" shall mean a 12-month
period beginning on an Employee's Anniversary Date during which the Employee
has not completed more than 500 Hours of Employment (as defined in section
3.7).  Notwithstanding the foregoing, the following periods shall not be deemed
to be Break in Service Years:
      (a)  If a Participant retires on his Disability Retirement Date,
           thereafter ceases to be totally and permanently disabled, and
           returns to the employ of an Employer, the period between his
           Disability Retirement Date and the date as of which he ceases to be
           totally and permanently disabled.
      (b)  If a Participant commences receiving benefits under a
           long-term disability benefit program maintained by an Employer and
           thereafter ceases to receive benefits under such program and returns
           to the employ of the Employer, the period during which he was
           receiving benefits under such program.
If an Employee incurs a Break in Service Year and prior to such Break in
Service Year has not completed five Years of Service, his Years of Service
completed prior to such a Break in Service Year shall be disregarded unless he
completes a Year of Service after such Break in Service Year and before the
total of such Break in Service Year and any ensuing consecutive Break in
Service Years equals the greater of five or the number of his

        


                                      -19-

<PAGE>   25
Years of Service (as defined in section 3.5 but without excluding Years of
Service completed prior to attaining age 18) prior to such Break in Service
Year.

     3.7 Hours of Employment.  "Hours of Employment" shall mean, for any
individual performing or who has performed services for one or more Employers
or nonparticipating Affiliated Companies, the sum of the following:
      (a)  All hours for which the individual is directly or indirectly
           paid or entitled to payment by an Employer or nonparticipating
           Affiliated Company for the performance of duties.  These hours shall
           be credited to the individual for the computation period or periods
           in which the duties are performed.
      (b)  Except as provided in section 3.7(e) below, all hours for
           which the individual is directly or indirectly paid or entitled to
           payment by an Employer or nonparticipating Affiliated Company for
           reasons (such as vacation, holiday, sickness, incapacity, layoff,
           jury duty, leave of absence, Military Service, or disability) other
           than for the performance of duties.  These hours shall be credited
           to the individual for the computation period or periods in which the
           period during which no duties are performed occurs, beginning with
           the first unit of time to which the payment relates.
      (c)  All hours for which back pay, irrespective of mitigation of
           damages, has been awarded, agreed to, or paid by an Employer or
           nonparticipating Affiliated Company, with no duplication of credit
           for hours.  These hours shall be credited to the individual for the
           computation period or periods to which the award or agreement
           pertains rather than the computation period in which the award,
           agreement, or payment is made.
      (d)  Except as provided in section 3.7(e) below, eight Hours of
           Employment per day for each working day that an individual is absent
           from work without pay for an



                                      -20-



<PAGE>   26


           approved leave of absence, voluntary time, sick time, disciplinary
           leave, or Military Service if the individual returns to the employ
           of an Employer or nonparticipating Affiliated Company within 90
           days after the end of such period.  These hours shall be credited
           to the individual for the computation period or periods in which
           the period during which no duties are performed occurs, beginning
           with the first such period.
      (e)  Eight Hours of Employment per day for each working day that
           an individual is absent from work with or without pay because of
           pregnancy of the individual, birth of a child to the individual,
           placement of a child with the individual in connection with the
           adoption of such child by such individual, or caring for such child
           for a period beginning immediately following such birth or
           placement.  The Committee may, in its discretion, request such
           information from the individual as the Committee shall deem relevant
           in order to verify that an absence is for the reasons described in
           this subsection (e).

           Notwithstanding the foregoing, no more than 501 Hours of Employment
           shall be credited under this subsection (e) on account of any such
           pregnancy or placement if the individual does not return to the
           employ of an Employer or participating Affiliated Company within 90
           days after the end of the period approved for such absence.  Hours
           credited under this subsection (e) shall be credited to the
           individual only in the year in which the absence begins if the
           crediting is necessary to prevent a Break in Service Year for such
           year; or, in any other case, in the immediately following year;
           provided, however, that if more than 501 hours are credited under
           this subsection (e) on account of any



                                      -21-



<PAGE>   27

           such pregnancy or placement, the excess over 501 hours shall be
           credited to the period or periods to which it relates.
      (f)  Notwithstanding the foregoing, any individual whose
           compensation is not computed on the basis of hours worked and who
           normally performs services for any Employer or nonparticipating
           Affiliated Company during its entire work day shall be credited with
           ten Hours of Employment for each working day in any period during
           which he is entitled to receive compensation from the Employer or
           nonparticipating Affiliated Company for the performance of services
           pursuant to section 3.7(a) and eight Hours of Employment for each
           working day in any period during which such individual performed no
           duties but is entitled to Hours of Employment under section 3.7(b)
           or (c).

Hours of Employment credited under this section 3.7 shall comply with the rules
set forth in 29 C.F.R. section 2530.200b-2(b) and (c), which rules are hereby
incorporated by reference.

     3.8 Employment by Related Entities.  If an Employee's employer is a
nonparticipating Affiliated Company, any period in which the Employee is
employed by the nonparticipating Affiliated Company, while such membership or
common control as defined in section 2.1(c) exists, shall be taken into account
for purposes of satisfying the eligibility service requirement set forth in
section 3.1 and measuring such Employee's Years of Service to the same extent
it would have been had such period of employment been employment by an
Employer.

     3.9 Leased Employees.  A person who is not an Employee of an Employer or
nonparticipating Affiliated Company and who performs services for an Employer
or a nonparticipating Affiliated Company pursuant to an agreement between the
Employer or nonparticipating Affiliated Company and a leasing organization

        

                                      -22-



<PAGE>   28
shall be considered a "leased employee" if such person performed the services
on a substantially full-time basis for a year and the services are of a type
historically performed by employees.  A person who is considered a "leased
employee" of an Employer or nonparticipating Affiliated Company shall not be
considered an Employee for purposes of participating in this Plan or receiving
any contribution or benefit under this Plan.  A leased employee shall be
excluded from this Plan regardless of whether the leased employee participates
in any plan maintained by the leasing organization.  However, if a leased
employee participates in the Plan as a result of subsequent employment with an
Employer, his previous service as a leased employee shall be counted in
calculating his Years of Service.  Notwithstanding the preceding provisions of
this section 3.9, a leased employee will be included as an Employee for
purposes of applying the requirements described in Code section 414(n)(3) and
for purposes of determining the number and identity of Highly Compensated
Employees.



                                      -23-



<PAGE>   29

                           Article IV.  Contributions

        4.1 Employee Allotments.
        (a) Amount of Allotments.  Each Participant may make a regular
            allotment to the Plan.  Such allotment shall not be less than 1
            percent nor more than--
            (1)  Prior to April 1, 1992, 12 percent of his
                 Compensation Rate, in incremental percentages of
                 1 percent;
            (2)  On and after April 1, 1992 and prior to
                 September 1, 1993, 14 percent of his Compensation Rate, in
                 incremental percentages of 1 percent, or
            (3)  On and after September 1, 1993, 15 percent of his
                 Compensation Rate, in incremental percentages of 1 percent.
            Allotments will be effected by Voluntary Deductions, Salary
            Reductions, or any combination thereof, as elected by the
            Participant.  The amount of such Voluntary Deductions or Salary
            Reductions shall be transferred to the Trustee after each pay
            period; provided, however, that a Participant's Salary Reduction
            allotments shall not exceed
            (A)  Prior to October 1, 1990, 6 percent of the Participant's 
                 Compensation Rate, subject to adjustment pursuant to section 
                 5.1 of the Plan as in effect on April 1, 1989;
            (B)  On and after October 1, 1990 and prior to April 1, 1992, 6 
                 percent of the Participant's Compensation Rate;
            (C)  On and after April 1, 1992 and prior to September 1, 1993, 8 
                 percent of the Participant's Compensation Rate; or
            (D)  On and after September 1, 1993, 8 percent of the
                 Participant's Compensation Rate, if the Participant is a
                 Highly Compensated Employee, or



                                      -24-



<PAGE>   30
                  9 percent of the Participant's Compensation Rate if the
                  Participant is not a Highly Compensated Employee;
            and further provided, however, that Voluntary Deductions and Salary
            Reductions shall be limited as provided in sections 4.8 and 4.11.

            Notwithstanding the foregoing, the Committee may, in its sole
            discretion, (1) reduce the Salary Reduction allotments permitted by
            a group of Participants if, in the opinion of the Committee, it is
            advisable to do so in order to satisfy the requirements of section
            4.8 or 4.13; or (2) reduce the Voluntary Deduction allotments
            permitted by a group of Participants if, in the opinion of the
            Committee, it is advisable to do so in order to satisfy the
            requirements of section 4.11 or 4.13.
      (b)   Changes in Allotments.  The allotment of Voluntary Deductions
            and/or Salary Reductions designated by a Participant shall continue
            in effect, notwithstanding any change in his Compensation Rate,
            until the Participant shall change such allotment; provided,
            however, that such allotment shall in no event be less than 1
            percent, nor more than--
            (1)  12 percent of his Compensation Rate, in incremental 
                 percentages of 1 percent, prior to April 1, 1992, or
            (2)  effective April 1, 1992, 14 percent, in incremental 
                 percentages of 1 percent, of the Participant's prevailing 
                 Compensation Rate, or
            (3)  effective September 1, 1993, 15 percent, in incremental 
                 percentages of 1 percent of the Participant's prevailing 
                 Compensation Rate.
            A Participant may change his allotment--
                 (A)  prior to August 1, 1991, as of the first day of any 
                      Accounting Period, or



                                      -25-


<PAGE>   31

                  (B)  on or after August 1, 1991, but prior to December 1, 
                       1993, as of the first day of any calendar quarter, or
                  (C)  on or after December 1, 1993, as of the first day of 
                       any month,
            by giving written directions to his Employer in the form prescribed
            by the Committee at least 20 days prior to the effective date of
            the change.  Prior to August 1, 1991, such changes may be made only 
            once in each calendar year except that any time a Participant's 
            Compensation Rate is changed he shall have the right to change his
            allotment as of the first day of any Accounting Period commencing 
            not more than 60 days thereafter by giving 20 days' written notice
            to his Employer in the form prescribed by the Committee.
       (c)  Voluntary Suspension of Allotments.  Any Participant may, by
            giving 20 days' written notice to his Employer in the form
            prescribed by the Committee, suspend his allotment of Voluntary
            Deductions and/or Salary Reductions, effective as of the end of any
            Accounting Period, either indefinitely or for any specified period
            provided that in either case the suspension shall be for at least 12
            full Accounting Periods.  In case of any such suspension of any
            allotments, the Employer's contributions on behalf of the
            Participant shall be automatically suspended for a like period.
       (d)  Automatic Suspension of Allotments.  A Participant's allotments 
            of Voluntary Deductions and Salary Reductions and the Employer's 
            contributions on behalf of the Participant shall be suspended 
            automatically for any period during which the Participant
            is absent without pay under any of the circumstances described in
            section 3.7(c), (d), or (e), and such an absence shall not
            constitute termination of service for purposes of any of the 
            provisions of Article IX.  A Participant may, by giving 20 days' 
            written notice to his Employer in the form prescribed by the 
            Committee, suspend his



                                      -26-



<PAGE>   32


            allotment of Voluntary Deductions and/or Salary Reductions for any
            period during which he is absent from work under any of the
            circumstances described in section 3.7(b) or (c) and receiving
            Compensation at a reduced Compensation Rate, in which case the
            Employer contributions on behalf of such Participant shall be
            automatically suspended for a like period.

     4.2 Employer Savings Plan Contributions.  Each Employer shall contribute,
to the Salary Reduction Account of each of its participating Employees, an
amount equal to 25 percent of the Salary Reduction allotment of such
Participant; provided, however, that Salary Reduction allotments in excess of 4
percent of the Participant's Compensation Rate shall be disregarded.  In cases
where the Participant's Salary Reduction allotment is less than 4 percent of
his Compensation Rate, the Employer shall contribute to the Voluntary Deduction
Account of such participating Employee an amount equal to 25 percent of the
smaller of (a) his Voluntary Deduction allotment, or (b) 4 percent of his
Compensation Rate reduced by his Salary Reduction allotment.

Effective as of the first pay period following the date on which a Participant
has completed ten Years of Service, 5 percent shall be substituted for 4
percent in each place that it appears in the preceding paragraph.

For periods beginning on or after September 1, 1993, effective as of the first
pay period following the date on which a Participant has completed 25 Years of
Service or as of September 1, 1993, if later, 6 percent shall be substituted
for 4 percent in each place that it appears in the first paragraph of this
section 4.2.

Notwithstanding the foregoing, the Committee, in its sole discretion, may
reduce the Employer contribution on behalf of a



                                      -27-



<PAGE>   33


group of Participants if, in the opinion of the Committee, it is advisable to
do so in order to satisfy the contribution percentage test specified in section
4.11.

     4.3  Employer ESOP Contributions.
     (a)  Basic ESOP Contribution.  Effective on and after
          April 1, 1989, each Employer shall contribute to the ESOP Account
          of each of its participating Employees each pay period an amount
          equal to the difference, if any, between (1) and (2) below:
            (1)  75 percent of the sum of the Salary Reduction and
                 Voluntary Deduction allotments of such Participant for such
                 pay period; provided, however, that Salary Reduction and
                 Voluntary Deduction allotments shall be disregarded to the
                 extent that they exceed, in the aggregate, 4 percent of such
                 Participant Compensation Rate.  Effective as of the dates
                 specified in section 4.2--
                 (A)  the 4 percent shall be increased to 5 percent for 
                      Participants who have completed ten Years of Service, and
                 (B)  for periods beginning on or after September 1, 1993, the
                      4 percent shall be increased to 6 percent for 
                      Participants who have completed 25 Years of Service.
            (2)  The value of the shares of MCN Stock allocated to the ESOP 
                 Account of such Participant pursuant to section 14.4(d) for 
                 such pay period.  The value of shares allocated under section
                 14.4(d) shall be the market value thereof as of the last day 
                 of the pay period for which the shares are allocated, with 
                 the market value to be determined by the Committee in a 
                 nondiscriminatory manner.
      (b)  Contribution of Principal, Interest, or Other Payments.  Each
           Employer also shall contribute to the ESOP its proportionate share
           of any additional amount necessary to make principal, interest, or
           other payments required



                                      -28-


<PAGE>   34

           by the terms of any loan made to the ESOP in accordance with
           section 14.4.  Each Employer's proportionate share shall be equal
           to the proportion that its contributions under section 4.3(a) bears
           to the total contributions under section 4.3(a).

           Effective November 1, 1989, each Employer also may make additional
           contributions to make principal, interest, or other payments in
           accordance with the terms of any loan made to the ESOP in
           accordance with section 14.4.
      (c)  Dividend-Related Contributions.  Effective November 1, 1989,
           each Employer also shall contribute to the ESOP Account of each of
           its participating Employees such amounts as may be necessary to
           acquire for the ESOP Account of such Participant shares of MCN Stock
           having a fair market value equal to the amount of any dividends on
           shares of MCN Stock allocated to the ESOP Account of such
           Participant that were used to repay an ESOP loan in accordance with
           section 14.4(c).  Such contributions shall be made on, or as soon as
           practicable after, each date on which dividends on allocated shares
           of MCN Stock are used to repay a loan.  In no event shall the shares
           of MCN Stock acquired with contributions under this subsection (c)
           be allocated to the ESOP Account of such Participant later than the
           last day of the Plan Year during which (but for the use of the
           dividend to repay the loan) the dividend giving rise to such
           contribution would have been allocated to the ESOP Account of such
           Participant.

     4.4 Additional Employer Contributions.  Effective January 14, 1991, if a
Participant receiving payments (based upon 40 or more hours per week) under the
terms of any Workers' Compensation law does not have sufficient compensation to
make Salary Reduction or Voluntary Deduction allotments in an amount
equal to the amount of the Participant's allotments as in effect during the
Participant's last period of active service, then the



                                      -29-



<PAGE>   35

Participant's Employer shall contribute on behalf of the Participant such
additional amount as would have been contributed by the Employer under sections
4.2 and 4.3 on behalf of such Participant had the Participant's allotments been
continued at the rate in effect during the Participant's last period of active
service.  Additional contributions under this section 4.4 shall be treated for
accounting purposes as if made under section 4.2 or 4.3, as applicable, except
such contributions shall not be considered when computing the Contribution
Percentage (as defined in section 2.1(n).

     4.5    Rollover Contributions.
     (a)    From Qualified Plan.  If an Employee receives, either before
            or after becoming an Employee--
            (1)  prior to January 1, 1993, a qualified total distribution 
                 (within the meaning of Code section 402(a)(5)(E)) or,
            (2)  effective January 1, 1993, an eligible rollover
                 distribution (within the meaning of Code section 402(c)(4))
            from an employees' trust described in Code section 401(a) which is
            exempt from tax under Code section 501(a) or from a qualified
            annuity plan described in Code section 403(a) (other than an
            employees' trust or an annuity plan under which the Employee was an
            Employee within the meaning of Code section 401(c)(1) at the time
            contributions were made on his behalf under such trust or annuity
            plan), then such Employee may transfer and deliver to the
            Committee, to be credited to his Employee Salary Reduction Account
            as if it were a Salary Reduction allotment, an amount which does
            not exceed the amount of such qualified total distribution or
            eligible rollover distribution (including any proceeds from the 
            sale of any property received as a part of such qualified total 
            distribution or eligible



                                      -30-



<PAGE>   36

            rollover distribution) less, in the case of a qualified total
            distribution, the amount considered contributed to such trust or
            annuity plan by the Employee.
      (b)   From Individual Retirement Account or Annuity.  If--
            (1)  an Employee receives, either before or after
                 becoming an Employee, a distribution or distributions from an
                 individual retirement account or individual retirement annuity
                 (within the meaning of Code section 408) or from a retirement
                 bond (within the meaning of Code section 409);
            (2)  no amount in such account, no part of the value of such 
                 annuity, or no part of the value of the proceeds of such bond
                 is attributable to any source other than--
                 (A)  prior to January 1, 1993, a qualified total distribution
                      (within the meaning of Code section 402(a)(5)(E)), or
                 (B)  effective January 1, 1993, an eligible rollover 
                      distribution (within the meaning of Code section 
                      402(c)(4))
                 from an employees' trust described in Code section 401(a)
                 which is exempt from tax under Code section 501(a) or annuity
                 plan described in Code section 403(a) (other than an
                 employees' trust or an annuity plan under which the Employee
                 was an Employee within the meaning of Code section 401(c) at
                 the time contributions were made on his behalf under such
                 trust or annuity plan) and any earnings on such a qualified
                 total distribution or eligible rollover distribution; and
            (3)  for rollovers prior to January 1, 1993, the amount received 
                 represents the entire amount in such account, the entire 
                 value of such annuity or the entire value of such bond,



                                      -31-



<PAGE>   37

           then such Employee may transfer and deliver to the Committee, to be
           credited to his Salary Reduction Account as if it were a Salary
           Reduction allotment, such distribution or distributions.
      (c)  Timing and Substantiation.  Any transfer and delivery
           pursuant to this section 4.5 shall be delivered by the Employee to
           the Committee and by the Committee to the Trustee on or before the
           sixtieth day after the day on which the Employee receives the
           distribution or on or before such later date as may be prescribed by
           law.  Any such transfer and delivery must be accompanied by--
           (1)  a statement of the Employee that to the best of his knowledge 
                the amount so transferred meets the conditions specified in 
                this section 4.5, and
           (2)  a copy of such documents as may have been received by the 
                Employee advising him of the amount and the character of such 
                distribution.
            Notwithstanding the foregoing, the Committee shall not accept a
            rollover contribution if, in its judgment, such acceptance would
            cause the Plan to violate any provision of the Code or Regulations.
       (d)  Deemed Allotment for Certain Purposes.  A rollover contribution 
            pursuant to this section 4.5 shall be deemed to be an allotment of
            a Participant for purposes of the value of a Participant's fund 
            account as provided in section 8.2 and in determining the amount 
            distributable to a Participant, the provisions of Article IX that 
            are applicable to Salary Reduction allotments will be used, 
            pursuant to section 9.1, but not for purposes of determining the 
            amount of the contribution to be made on behalf of a Participant 
            by his Employer pursuant to section 4.2, 4.3, or 4.4 or 
            calculating the Annual Addition of such Participant.
       (e)  Deemed Participation for Certain Purposes.  If the amount of
            rollover contribution is made by an Employee prior to his becoming a
            Participant, such Employee shall, until such time as he becomes a
            Participant, be



                                      -32-



<PAGE>   38

            deemed to be a Participant for all purposes of the Plan except for
            purposes of any determination of when he becomes a Participant
            pursuant to section 3.1 and the making of allotments pursuant to
            section 4.1(a).

     4.6 Transfers from the MichCon Investment and Stock Ownership Plan.
Effective April 1, 1989, if an Employee who previously had participated in the
MichCon Investment and Stock Ownership Plan (the "Investment Plan") becomes a
Participant in the Plan and the Participant's plan account in the Investment
Plan is transferred to the Plan in accordance with section 3.3 of the
Investment Plan, the Plan shall accept such transfer.  Amounts transferred
shall be 100 percent vested at all times and shall be treated for all purposes
in the same manner as they were treated under the Investment Plan; that is:
      (a)  Amounts attributable to Employer salary reduction allotments
           under the Investment Plan shall be allocated to the Participant's
           Employee Salary Reduction Account;
      (b)  Amounts attributable to voluntary deduction allotments under
           the Investment Plan shall be allocated to the Participant's Employee
           Voluntary Deduction Account;
      (c)  Amounts attributable to Employer Investment Plan
           contributions shall be allocated to the Participant's Employer
           Salary Reduction Account or Employer Voluntary Deduction Account, as
           the case may be; and
      (d)  Amounts transferred from the ESOP Account of the Participant
           in the Investment Plan shall be allocated to the Participant's ESOP
           Account.
Notwithstanding the foregoing, amounts transferred shall not be used for
purposes of determining the amount of the contribution to be made on behalf of
a Participant by the Employer pursuant to section 4.2, 4.3, or 4.4, or
calculating the Actual Deferral Percentage, Contribution Percentage, or Annual
Addition of the Participant.



                                      -33-



<PAGE>   39


      4.7  Transfers from the MichCon Employee Stock Ownership Plan.

      (a)  In General.  The Company has previously maintained the MichCon
           Employee Stock Ownership Plan (the "Tax Credit ESOP"), which was a
           plan separate and distinct from the MichCon Employee Stock Ownership
           Plan for Non-Union Employees which constitutes a part of the Plan. 
           The Company terminated the Tax Credit ESOP and, upon such
           termination, a portion of the assets of the Tax Credit ESOP were
           transferred to this Plan.  The purpose of this section 4.7, which is
           effective as of January 25, 1991, is to set forth specific
           provisions applicable to the assets so transferred.  In the event of
           any conflict between any other provision of the Plan and this
           section 4.7 the terms of this section 4.7 shall govern with respect
           to amounts transferred from the Tax Credit ESOP, adjusted for
           earnings and losses thereon.

      (b)  Allocation to ESOP Account.  All amounts transferred from the
           Tax Credit ESOP attributable to Plan Years 1975 through 1982 on
           behalf of any Participant or former Participant who has an account
           balance in this Plan shall be allocated to the ESOP Account of such
           Participant or former Participant.  The amounts transferred to the
           ESOP Account of a Participant or former Participant, adjusted for
           any earnings or losses thereon, shall, subject to the special rules
           set forth in this section 4.7, be treated in the same manner as
           other assets of the ESOP Accounts for all purposes of this Plan,
           including, but not limited to, distributions, loans, investments,
           and diversification of investments.  The amounts transferred shall
           not be deemed to constitute an Employee Allotment or an Employer 
           Contribution for discrimination testing or any other purpose.

      (c)  Allocation to MCN Salary Reduction Account.  All amounts
           transferred from the Tax Credit ESOP



                                      -34-



<PAGE>   40

            attributable to Plan Years 1983 through 1986 on behalf of any
            Participant or former Participant who has an account balance in
            this Plan shall be allocated to the Salary Reduction Account of
            such Participant or former Participant.  The amounts transferred to
            the Salary Reduction Account of a Participant or former
            Participant, adjusted for any earnings or losses thereon, shall,
            subject to the special rules set forth in this section 4.7, be
            treated in the same manner as other assets of the Salary Reduction
            Accounts for all purposes of this Plan, including, but not limited
            to, distributions, loans, investments, and diversification of
            investments.  The amounts transferred shall not be deemed to
            constitute an Employee Allotment or an Employer Contribution for
            discrimination testing or any other purpose.
      (d)   Vesting.  All amounts transferred from the Tax Credit ESOP on
            behalf of any Participant or former Participant, adjusted for any
            earnings or losses thereon, shall at all times be fully vested and
            nonforfeitable.

     4.8    Limitations on Salary Reduction Allotments.
      (a)   Dollar Limitation.  In no event shall any Employer make
            Salary Reduction allotments for any calendar year, with respect to
            any Participant in excess of $7,627 (for 1989) (as adjusted by the
            Secretary of the Treasury to reflect increases in the cost of
            living).  This limit shall be applied by aggregating all plans and
            arrangements maintained by the Company and all Affiliated Companies
            that provide for elective deferrals (as defined in Code section
            402(g)).
      (b)   ADP Test.  In addition to the limitations set forth elsewhere
            in this Plan, one of the following tests must be satisfied for the
            Plan Year:
            (1)  The Average Actual Deferral Percentage for Highly
                 Compensated Employees who are eligible to



                                      -35-



<PAGE>   41

                 participate for the Plan Year shall not exceed the Average
                 Actual Deferral Percentage for Nonhighly Compensated
                 Employees who are eligible to participate for the Plan Year
                 multiplied by 1.25; or
            (2)  The Average Actual Deferral Percentage for Highly
                 Compensated Employees who are eligible to participate for the
                 Plan Year shall not exceed the Average Actual Deferral
                 Percentage for Nonhighly Compensated Employees who are
                 eligible to participate for the Plan Year multiplied by two,
                 provided that the Average Actual Deferral Percentage for such
                 Highly Compensated Employees does not exceed the Average
                 Actual Deferral Percentage for such Nonhighly Compensated
                 Employees by more than two percentage points or such lesser
                 amount as the Secretary of Treasury shall prescribe in
                 accordance with Code section 401(m)(9) to prevent the multiple
                 use of this alternative limitation with respect to any Highly
                 Compensated Employee.  Any such restriction on the multiple
                 use of the alternative limit shall be implemented pursuant to
                 uniform rules adopted by the Committee.
      (c)  Determination of Actual Deferral Percentages.  For purposes
           of the Actual Deferral Percentage test described in this section
           4.8--
            (1)  An Elective Deferral will be taken into account for a Plan 
                 Year only if it relates to Compensation that either would 
                 have been received by the Eligible Employee in the Plan
                 Year (but for the deferral election) or is attributable to
                 services performed by the Eligible Employee in the Plan Year
                 and would have been received by the Eligible Employee within 
                 2 1/2 months after the close of the Plan Year (but for the 
                 deferral election);



                                      -36-



<PAGE>   42

            (2)  An Elective Deferral will be taken into account for a Plan 
                 Year only if it is allocated to the Eligible Employee as of a
                 date within that Plan Year.  For this purpose, an Elective 
                 Deferral is considered allocated as of a date within a Plan 
                 Year if the allocation is not contingent on participation or 
                 performance of services after such date and the Elective 
                 Deferral is actually paid to the Trust no later than 12 
                 months after the Plan Year to which the contribution relates;
            (3)  The Actual Deferral Percentage for an Employee who is eligible 
                 to participate shall be computed by treating any Excess 
                 Deferral (as defined in section 4.9) as an Elective Deferral,
                 except to the extent provided by Regulations;
            (4)  The Actual Deferral Percentage for any Employee who is a 
                 participant under two or more section 401(k) plans or
                 arrangements that are maintained by the Company or an
                 Affiliated Company shall be determined as if all such Elective
                 Deferrals were made under a single arrangement; provided,
                 however, that no Elective Deferrals under an employee stock
                 ownership plan (as defined in Code section 4975(e)(7)) shall
                 be taken into account for purposes of this section 4.8;
            (5)  In the event that two or more plans which include
                 cash-or-deferred arrangements are considered as one plan for
                 purposes of Code section 401(a)(4) or 410(b), the
                 cash-or-deferred arrangements included in such plans shall be
                 treated as one arrangement for purposes of this section 4.8;
            (6)  For purposes of determining the Actual Deferral Percentage of
                 an Employee who is a 5-percent owner of the Company or one of
                 the ten Highly Compensated Employees paid the most 
                 Compensation during the year, the Elective Deferrals and 
                 Compensation of such Employee shall include the



                                      -37-



<PAGE>   43


                 Elective Deferrals and Compensation of Family Members, and
                 such Family Members shall be disregarded in determining the
                 Actual Deferral Percentage for Employees who are Nonhighly
                 Compensated Employees; and
            (7)  The determination and treatment of the Elective
                 Deferrals and Actual Deferral Percentage of any Employee shall
                 satisfy such other requirements as may be prescribed by the
                 Secretary of Treasury.

     4.9 Distribution of Excess Deferrals.  "Excess Deferrals" means excess
deferrals as defined under Code section 402(g).  Notwithstanding any other
provision of the Plan, the Excess Deferral, if any, of each Employee with
respect to a calendar year plus any income and minus any loss allocable thereto
shall be distributed no later than April 15 of the following calendar year to
each Employee who claims an Excess Deferral for the preceding calendar year.
Excess Deferrals shall be treated as Annual Additions under the Plan.

The Employee's claim shall be in writing; shall be submitted to the Committee
no later than March 1; shall specify the Employee's Excess Deferral for the
preceding calendar year; and shall be accompanied by the Employee's written
statement that if such amount is not distributed, such Excess Deferral, when
added to amounts deferred under other plans or arrangements described in Code
section 401(k), 408(k), or 403(b), exceeds the limit imposed on the Employee by
Code section 402(g) for the year in which the deferral occurred.

Notwithstanding the preceding paragraph, the Employer may notify the Plan on
behalf of the individual of Excess Deferrals to the extent that the individual
has Excess Deferrals for the calendar year calculated by taking into account
only elective deferrals under this Plan and other plans of the Company and any
Affiliated Company.

        

                                      -38-



<PAGE>   44

The Excess Deferral distributed to an Employee with respect to a calendar year
shall be adjusted for any income or loss thereon for such calendar year and for
the period between the end of such calendar year and the date of distribution.
The income or loss allocable to such calendar year shall be determined by
multiplying the income or loss for such calendar year allocable to the
Employee's Salary Reduction Account by a fraction, the numerator of which is
the Excess Deferral of the Employee for such calendar year and the denominator
of which is the Employee's Salary Reduction Account balance on the last day of
such calendar year.  The income or loss allocable to the period between the end
of such calendar year and the date of distribution shall be equal to 10 percent
of the income or loss allocable to the Excess Deferral for the preceding
calendar year multiplied by the number of calendar months that have elapsed
from the end of the preceding calendar year to the date of distribution.  A
distribution occurring on or before the fifteenth day of the month shall be
treated as having been made on the last day of the preceding month and a
distribution occurring after such fifteenth day shall be treated as having been
made on the first day of the following month.  

In the event that an Employee's Salary Reduction allotments are distributed to
such Employee under this section 4.9, any Employer contributions attributable
thereto plus any income and minus any loss allocable thereto shall be
forfeited.

     4.10 Distribution or Recharacterization of Excess Contributions.
      (a)  Determination of Excess Contributions.  "Excess
           Contributions" means, with respect to any Plan Year, 
           the excess of--
           (1)  the aggregate amount of Elective Deferrals
                actually paid over to the Trust on behalf of
                Highly Compensated Employees for such Plan Year, over



                                      -39-



<PAGE>   45


            (2)  the maximum amount of such Elective Deferrals
                 permitted under the limitations of section 4.8(b), determined
                 by reducing Elective Deferrals as follows:
                 (A)   First, the Actual Deferral Percentage (as defined in 
                       section 2.1(b)) of the Highly Compensated Employee with
                       the highest Actual Deferral Percentage is reduced to 
                       the extent necessary to satisfy the test described in 
                       section 4.8(b) or to cause such percentage to equal the
                       Actual Deferral Percentage of the Highly Compensated 
                       Employee with the next highest Actual Deferral 
                       Percentage.
                  (B)  Second, this process is repeated until the test 
                       described in section 4.8(b) is satisfied.
            Excess Contributions shall be treated as Annual Additions under the
            Plan.

            For purposes of this section 4.10, to the extent permitted by the
            Code, the Excess Contributions shall be reduced by the amount of
            any Excess Deferrals included in such Excess Contributions and
            distributed to the Employee pursuant to section 4.9.
       (b)  Distribution or Recharacterization.  Notwithstanding any
            other provision of the Plan, either--
            (1)  Excess Contributions with respect to a calendar
                 year plus any income and minus any loss allocable thereto
                 shall be distributed no later than the last day of the
                 following calendar year to Employees on whose behalf such
                 Excess Contributions were made for the preceding calendar
                 year; or
            (2)  at the election of the Employee and to the extent
                 permitted by the Code, the Excess Contributions



                                      -40-



<PAGE>   46
                  shall be treated as distributed to the Employee and then
                  contributed by the Employee to the Plan as a Voluntary
                  Deduction allotment.
      (c)  Adjustment for Income and Loss.  The Excess Contributions to
           be distributed to an Employee with respect to a calendar year shall
           be adjusted for any income or loss thereon for such calendar year
           and for the period between the end of such calendar year and the
           date of distribution.  The income or loss allocable to such calendar
           year shall be determined by multiplying the income or loss for such
           calendar year allocable to the Employee's Salary Reduction Account
           by a fraction, the numerator of which is the Excess Contributions
           for such calendar year and the denominator of which is the
           Employee's Salary Reduction Account balance on the last day of such
           calendar year.  The income or loss allocable to the period between
           the end of such calendar year and the date of distribution shall be
           equal to 10 percent of the income or loss allocable to the Excess
           Contributions for the preceding calendar year multiplied by the
           number of calendar months that have elapsed from the end of the
           preceding calendar year to the date of distribution.  A distribution
           occurring on or before the fifteenth day of the month shall be
           treated as having been made on the last day of the preceding month
           and a distribution occurring after such fifteenth day shall be
           treated as having been made on the first day of the following month.

           In the event that an Employee's Salary Reduction allotments are
           distributed to such Employee under this section 4.10, any Employer
           contributions attributable thereto plus any income and minus any 
           loss allocable thereto shall be forfeited.




                                      -41-



<PAGE>   47

     4.11 Limitations on Voluntary Deduction Allotments and Employer
Contributions.
      (a)  ACP Test.  In addition to the limitations set forth elsewhere
           in this Plan, both the ESOP and the non-ESOP portions of the Plan,
           tested separately, must satisfy one of the following tests for each
           Plan Year:
           (1)  The Average Contribution Percentage for Highly Compensated 
                Employees who are eligible to participate for the Plan Year 
                shall not exceed the Average Contribution Percentage for 
                Nonhighly Compensated Employees who are eligible to
                participate for the Plan Year multiplied by 1.25; or
           (2)  The Average Contribution Percentage for Highly Compensated 
                Employees who are eligible to participate for the Plan Year 
                shall not exceed the Average Contribution Percentage for 
                Nonhighly Compensated Employees who are eligible to
                participate for the Plan Year multiplied by two, and the
                Average Contribution Percentage for such Highly Compensated
                Employees shall not exceed theAverage Contribution Percentage
                for such Nonhighly Compensated Employees by more than two
                percentage points or such lesser amount as the Secretary of
                Treasury shall prescribe in accordance with Code section
                401(m)(9) to prevent the multiple use of this alternative
                limitation with respect to any Highly Compensated Employee.
                Any such restriction on the multiple use of the alternative
                limit shall be implemented pursuant to uniform rules adopted
                by the Committee.
      (b)  Determination of Contribution Percentages.  For purposes of
           the Average Contribution Percentage test described in this section
           4.11--
           (1)  the Contribution Percentage for any Employee who is a Highly 
                Compensated Employee for the Plan Year and who is eligible to 
                make Employee contributions



                                      -42-



<PAGE>   48
                 or to receive Employer contributions or Elective Deferrals
                 allocated to his account under two or more plans described in
                 Code section 401(a) or arrangements described in Code section
                 401(k) that are maintained by the Company or an Affiliated
                 Company shall be determined as if all such contributions and
                 Elective Deferrals were made under a single plan; provided,
                 however, that contributions and Elective Deferrals under an
                 employee stock ownership plan (as defined in Code section
                 4975(e)(7)) shall not be combined with contributions and
                 Elective Deferrals under a plan that is not an employee stock
                 ownership plan.
            (2)  In the event that this Plan satisfies the requirements of 
                 Code section 410(b) only if aggregated with one or more other
                 plans, or if one or more other plans satisfy the
                 requirements of Code section 410(b) only if aggregated with
                 either the ESOP or the non-ESOP portion of this Plan, then
                 this section 4.11 shall be applied by determining the
                 Contribution Percentages of Employees as if all such plans
                 were a single plan. The ESOP portion of the Plan will not be
                 used in conjunction with any other plan to satisfy the
                 requirements of Code section 401(a)(4) or 410(b).
            (3)  For purposes of the application of this section 4.11 to an 
                 Employee who is a 5-percent owner of the Employer or one of  
                 the ten Highly Compensated Employees paid the most
                 Compensation during the year, Voluntary Deduction allotments,
                 Employer contributions, and Compensation (and, if applicable,
                 Elective Deferrals under this Plan and Employee contributions,
                 Employer contributions, and Elective Deferrals under other
                 plans maintained by the Company or an Affiliated Company) of 
                 such Participant shall include such allotments, contributions,
                 Elective Deferrals, and



                                      -43-



<PAGE>   49

                 Compensation of Family Members, and such Family Members shall
                 be disregarded in determining the Contribution Percentage for
                 Employees who are Nonhighly Compensated Employees.
            (4)  The determination and treatment of the Contribution Percentage 
                 of any Employee shall satisfy such other requirements as may 
                 be prescribed by the Secretary of Treasury.

     4.12  Disposition of Excess Aggregate Contributions.
      (a)  Determination of Excess Aggregate Contributions.  
           "Excess Aggregate Contributions" means, with respect to any Plan 
           Year, the excess of--
           (1)   the aggregate amount of Employer contributions
                 under section 4.2 or sections 4.3(a) and 14.4(d) (as
                 applicable) and Voluntary Deduction allotments (and any
                 Elective Deferrals taken in account in computing Contribution
                 Percentages under section 4.11(b)) actually made on behalf of
                 Highly Compensated Employees for such Plan Year, over
           (2)   the maximum amount of such contributions permitted under the 
                 limitations of section 4.11(a), determined by reducing such 
                 Employer contributions and Voluntary deduction allotments as 
                 follows:
                 (A)   First, the Contribution Percentage (as defined in
                       section 4.11(b)) of the Highly Compensated Employee with
                       the highest Contribution Percentage is reduced as
                       described in the following subsections of this section
                       to the extent necessary to satisfy the test described in
                       section 4.11(a) or to cause such percentage to equal the
                       Contribution Percentage of the Highly Compensated
                       Employee with the next highest Contribution Percentage.



                                      -44-



<PAGE>   50

                  (B)  Second, this process is repeated until the test 
                       described in section 4.11(a) is satisfied.
           Excess Aggregate Contributions shall be treated as Annual Additions
           under the Plan.

           For purposes of this section 4.12, the determination of an
           Employee's Excess Aggregate Contributions shall be made after first
           determining the Excess Deferral (as defined in section 4.9) and the
           Excess Contribution (as defined in section 4.10(a)) of such
           Employee.
      (b)  Distribution of Excess Voluntary Deduction Allotments.  To
           the extent necessary to satisfy the contribution percentage test
           specified in section 4.11, Voluntary Deduction allotments with
           respect to a calendar year plus any income and minus any loss
           allocable thereto for such calendar year and for the period between
           the end of such calendar year and the date of distribution shall be
           distributed no later than the last day of the following calendar
           year to the Highly Compensated Employees who made such Voluntary
           Deduction allotments for the preceding calendar year.

           The income or loss allocable to the Voluntary Deduction allotments
           for such calendar year returned to the Employee pursuant to this
           subsection shall be determined by multiplying the income or loss
           for such calendar year allocable to the Employee's Post-1986
           Voluntary Deduction Account by a fraction, the numerator of which
           is such Voluntary Deduction allotments returned to the Employee and
           the denominator of which is the Employee's Post-1986 Voluntary
           Deduction Account balance on the last day of such calendar year.

           The income or loss allocable to the period between the end of such
           calendar year and the date of distribution



                                      -45-



<PAGE>   51


            shall be equal to 10 percent of the income or loss allocable to the
            Voluntary Deduction allotments for the preceding calendar year
            returned to the Employee multiplied by the number of calendar
            months that have elapsed from the end of the preceding calendar
            year to the date of distribution.

            A distribution occurring on or before the fifteenth day of the
            month shall be treated as having been made on the last day of the
            preceding month and a distribution occurring after such fifteenth
            day shall be treated as having been made on the first day of the
            following month.
      (c)   Distribution of Excess Elective Deferrals Taken into Account.
            If, after returning all Voluntary Deduction allotments made by
            Highly Compensated Employees for the preceding calendar year, the
            contribution percentage test is still not satisfied, then to the
            extent necessary to satisfy such test, any Elective Deferrals taken
            into account for such test plus any income and minus any loss
            allocable thereto for such calendar year and for the period between
            the end of such calendar year and the date of distribution shall be
            distributed no later than the last day of the following calendar
            year to the Highly Compensated Employees on whose behalf such
            Elective Deferrals were made for the preceding calendar year.

            The income or loss allocable to the Elective Deferrals for such
            calendar year returned to the Employee pursuant to this subsection
            shall be determined by multiplying the income or loss for such
            calendar year allocable to the Employee's Salary Reduction Account
            by a fraction, the numerator of which is such Elective
            Deferrals returned to the Employee and the denominator of which is
            the Employee's Salary Reduction Account balance on the last day of
            such calendar year.



                                      -46-



<PAGE>   52
            The income or loss allocable to the period between the end of such
            calendar year and the date of distribution shall be equal to 10
            percent of the income or loss allocable to the Elective Deferrals
            for the preceding calendar year returned to the Employee multiplied
            by the number of calendar months that have elapsed from the end of
            the preceding calendar year to the date of distribution.

            A distribution occurring on or before the fifteenth day of the
            month shall be treated as having been made on the last day of the
            preceding month and a distribution occurring after such fifteenth
            day shall be treated as having been made on the first day of the
            following month.
      (d)   Distribution of Other Excess Employer Contributions.  If,
            after returning all Voluntary Deduction allotments and Elective
            Deferrals included in the Excess Aggregate Contributions, the
            contribution percentage test is still not satisfied, to the extent
            necessary to satisfy such test, the Employer contributions with
            respect to the calendar year made on behalf of Highly Compensated
            Employees and shares of MCN Stock allocated to Highly Compensated
            Employees under section 14.4(d) plus any income and minus any loss
            allocable thereto for such calendar year and for the period between
            the end of such calendar year and the date of distribution shall be
            forfeited and used to reduce Employer contributions to the Plan.

            The income or loss allocable to the Employer contributions under
            section 4.2 forfeited for such calendar year pursuant to this
            subsection shall be determined by multiplying the income or loss
            for such calendar year allocable to the Employer's Voluntary 
            Deduction Account and the Employer's Salary Reduction Account by a
            fraction, the numerator of which is such



                                      -47-



<PAGE>   53

            Employer contributions forfeited and the denominator of which is
            the sum of the Employer's Voluntary Deduction Account balance and
            the Employer's Salary Reduction Account balance, both determined on
            the last day of such calendar year.

            The income or loss allocable to the period between the end of such
            calendar year and the date of distribution shall be equal to 10
            percent of the income or loss allocable to the Employer
            contributions under section 4.2 for the preceding calendar year
            that were forfeited multiplied by the number of calendar months
            that have elapsed from the end of the preceding calendar year to
            the date of distribution.

            The income or loss allocable to any Employer contribution under
            section 4.3(a) or any shares of MCN Stock allocated to a Highly
            Compensated Employee under section 14.4(d) shall be calculated in a
            similar manner based upon the ESOP Account of the Participant.

            A distribution occurring on or before the fifteenth day of the
            month shall be treated as having been made on the last day of the
            preceding month and a distribution occurring after such fifteenth
            day shall be treated as having been made on the first day of the
            following month.

     4.13   Statutory (Code Section 415) Limitations on Allocations to Accounts.
Notwithstanding any other provision of the Plan, contributions under the Plan
shall be subject to the limitations set forth in Code section 415, which are
incorporated herein by reference.  For purposes of applying such limitations to
contributions under the Plan, the rules set forth in this section 4.13 shall be
applicable.



                                      -48-



<PAGE>   54

      (a)  Annual Addition.  The term "Annual Addition" means the amount
           allocated to a Participant's account during any calendar year that
           constitutes--
           (1)  Employer contributions;
           (2)  Employee contributions;
           (3)  forfeitures; and
           (4)  amounts described in Code sections 415(l)(1) and
                 419A(d)(2).
           The compensation limitation referred to in Code section
            415(c)(1)(B) shall not apply to--
                  (A)  any contribution for medical benefits (within the 
                       meaning of Code section 419A(f)(2)) after separation 
                       from service which is otherwise treated as an Annual 
                       Addition, or
                  (B)  any amount otherwise treated as an Annual Addition 
                       under Code section 415(l)(1).
           The Annual Addition for any calendar year before 1987 shall not be
           recomputed to treat all Employee contributions as an Annual
           Addition.
      (b)  Combined-Plan Limits.  In the case of an individual who was a
           Participant in the Plan on December 31, 1986, an amount shall be
           subtracted from the numerator of the defined contribution fraction
           (not exceeding such numerator) as prescribed by the Secretary of
           Treasury so that the sum of the defined benefit plan fraction and
           defined contribution plan fraction does not exceed 1.0 as of such
           date.

           Code section 415 shall be applied in such manner as to maximize the
           permissible contributions and benefits thereunder and, in
           determining the permissible amount of contributions under the Plan,
           any grandfathering provisions heretofore or hereafter adopted
           pursuant to Code section 415 shall be applicable.  For purposes of 
           applying the limitations set forth in Code section



                                      -49-



<PAGE>   55

            415(e), the MichCon Retirement Plan shall be the primary plan and
            any required reductions shall be made in the Annual Additions to
            this Plan.
      (c)   Reduction of Annual Additions.
            (1)  If the limitations of Code section 415 would be exceeded 
                 as a result of a reasonable error in estimating a
                 Participant's compensation or on account of such other limited
                 facts and circumstances as the Commissioner of Internal
                 Revenue finds justify the application of the rules hereinafter
                 set forth, the Annual Additions to the Participant's account
                 which exceed the applicable limitation shall be returned to
                 the Participant to the extent of all or any portion of any
                 Voluntary Deduction allotments which were made by him pursuant
                 to Article IV.  Any net earnings and gains allocable to such
                 allotments for the period between the date of such allotment
                 and the date returned shall also be repaid to the Participant
                 but such return of net earnings and gains will not be deemed a
                 further reduction of any excess Annual Additions.
            (2)  If the Participant made no Voluntary Deduction allotments or 
                 if, after returning all or part of such allotments in 
                 accordance with the previous paragraph, his Annual Additions 
                 still exceed the limitations of Code section 415, then such 
                 excess shall be returned to the Participant to the extent of 
                 all or any portion of any Salary Reduction allotments made on
                 behalf of such Participant, together with any net earnings 
                 and gains on such allotments as hereinabove described.
            (3)  If, after returning all or any portion of Voluntary Deduction
                 and Salary Reduction allotments of a Participant in accordance 
                 with the preceding paragraphs, his Annual Additions still 
                 exceed the limitations of Code section 415, such



                                      -50-



<PAGE>   56

                 portion of the Employer contributions under section 4.2 made
                 on behalf of the Participant as must be removed to meet the
                 limitations shall be allocated and reallocated to other
                 Participants' Savings Plan Accounts as contributions by the
                 Employer.
            (4)  If, after reallocating all or any portion of Employer 
                 contributions under section 4.2, a Participant's Annual 
                 Additions still exceed the limitation of Code section 415, 
                 such portion of the Employer contributions under section
                 4.3(a) made on behalf of the Participant and shares of MCN
                 Stock allocated to his ESOP Account under section 14.4(d) as
                 must be removed to meet the limitations shall be allocated and
                 reallocated to other Participant's ESOP Accounts as
                 contributions by the Employer.
            (5)  If, as a result of the allocation of forfeitures, a reasonable 
                 error in estimating a Participant's Compensation, or
                 under other limited facts and circumstances which the
                 Commissioner of the Internal Revenue Service finds justify the
                 availability of the following rules, any amount cannot be
                 allocated during the Plan Year in accordance with the
                 foregoing procedure without exceeding the applicable
                 limitations for one or more Participants, any remaining amount
                 shall be held unallocated in a special suspense account to be
                 allocated to Participants in the succeeding Plan Year or Plan
                 Years; provided, however, that (A) no Employer contributions
                 and no Voluntary Deduction allotments shall be made in such
                 succeeding Plan Year or Plan Years until such special suspense
                 account is exhausted by allocations and reallocations; (B) no
                 investment gains (or losses) or other income shall be
                 allocated to the special suspense account; and (C)



                                      -51-



<PAGE>   57

                  the amounts in the special suspense account shall be
                  allocated as soon as possible without violating the
                  limitations of this section 4.13.

















                                     -52-



<PAGE>   58

                        Article V.  Vesting in Accounts

      5.1 Employee Salary Reduction Accounts, Employee Post-1986 Voluntary
Deduction Account, and Employee Pre-1987 Voluntary Deduction Account.  The
Employee Salary Reduction Account, the Employee Post-1986 Voluntary Deduction
Account, and the Employee Pre-1987 Voluntary Deduction Account of each
Participant shall be fully vested and nonforfeitable at all times.

      5.2 Employer Salary Reduction Account, Employer Voluntary Deduction
Account, and ESOP Account.
      (a)  In General.  A Participant shall have a vested and
           nonforfeitable interest in his Employer Salary Reduction Account,
           Employer Voluntary Reduction Account, and ESOP Account after he has
           completed at least five Years of Service.  Prior to that time he
           shall have no vested interest in such accounts.
      (b)  Accelerated Vesting.  Notwithstanding section 5.2(a) above, a
           Participant shall be fully vested and have a nonforfeitable interest
           in his entire Employer Salary Reduction Account, Employer Voluntary
           Deduction Account, and ESOP Account if--
           (1)  while still an Employee, he attains age 65;
           (2)  while still an Employee, he dies or suffers a total and 
                permanent disability as defined in section 2.1(o); or
           (3)  while he is an Employee, contributions to the Plan are 
                completely discontinued or the Plan is terminated, or the Plan
                is partially terminated and such Participant is affected by 
                such partial termination.



                                     -53-



<PAGE>   59
                       Article VI.  Investment Provisions

     6.1 Investment of Contributions and Allotments.  Employer contributions
under sections 4.2, 4.3, and 4.4 and Employee allotments shall be invested in
accordance with the following provisions:
      (a)  The Employer contributions made pursuant to section 4.3(a)
           and (c) shall be invested in the MCN Stock fund, which fund is
           described in Article VII.
      (b)  Each Participant shall, by written direction to the Committee
           in the form prescribed by the Committee, direct that the Employer
           contributions made pursuant to section 4.2 and Employee allotments,
           including those made as a Salary Reduction, be invested in such
           funds offered by the Trustee as are selected by the Committee.
Employee allotments, including those made as a Salary Reduction, and the
portion of Employer contributions referenced in section 6.1(b) above, need not
be invested in the same fund.  A Participant shall direct the manner in which
the total of such allotments and such Employer contributions referenced in
section 6.1(b) above shall be divided, equally or otherwise, among the funds.

     6.2 Change of Investment Direction.  Any investment direction given by a
Participant under section 6.1 shall be deemed to be a continuing direction
until changed by the Participant.  A Participant may change any such direction
in accordance with such procedures as the Committee may from time to time
provide and apply in a nondiscriminatory manner.

     6.3 Transfers Between Investment Funds.  A Participant may direct that all
or any part of the value of his interest in any investment fund be transferred
to one or more of the other funds except that a Participant may not transfer
any amount from the



                                     -54-
<PAGE>   60

MCN Stock fund to the extent that the balance remaining in such fund immediately
after the transfer would be less than the value of his ESOP Account.
        
A transfer of all or any part of the value of a Participant's interest in the
Fixed Income fund may from time to time be restricted by the terms of agreements
which govern the investment of assets in such fund, in which event the Committee
shall give notice of such restrictions to the Participants.
        
Prior to September 1, 1991, transfers between funds shall be effected only as of
the first day of any Accounting Period upon written directions to the Committee
in the form prescribed by the Committee given at least 20 days prior to the
effective date of such transfer.  Prior to September 1, 1991, if a Participant
shall direct the transfer of all or any part of the value of his interest in a
fund, the Participant shall not be allowed to direct transfers to such fund for
a period of one year from the date of such transfer.
        
Prior to April 30, 1991, the procedures set forth above were equally applicable
to the Primark Corporation Stock fund.  After that date, such fund ceased to    
exist.
        



                                     -55-



<PAGE>   61


                         Article VII.  Investment Funds

     7.1 Investment Funds.  The Trustee shall establish, operate, and maintain
the following funds exclusively for the collective investment and reinvestment
of monies directed by the Committee to be invested in such funds on behalf of
Participants:
      (a)  MCN Stock Fund.  A MCN Stock fund which shall be invested solely in
           the common stock of MCN Corporation.
      (b)  Fixed Income Fund.  A Fixed Income fund which shall be invested, 
           except as hereinafter provided, in accounts or, effective as of 
           December 18, 1992, in marketable fixed income securities or
           accounts maintained by financial institutions which provide for
           fixed or variable rates of interest for specified periods of time.
           The terms of such agreements and the selection of such institutions
           shall be determined by the Company.  Investment advisors for
           marketable fixed income securities may use fixed income futures and
           options to reduce the effect of market volatility.
      (c)  Primark Corporation Stock Fund.  Until April 30, 1991, a Primark 
           Corporation Stock Fund to be invested in accordance with the
           terms of this paragraph (e).  Until April 12, 1991, the assets of
           the fund were and are to be invested solely in Primark Corporation
           Stock.  As soon as practicable after April 12, 1991, the shares of
           Primark Corporation Stock in the fund shall be sold and the proceeds
           of such sales shall be invested solely in any short-term fixed
           income fund described in section 8.1.  As of May 1, 1991 (or, if the
           sale of all shares of Primark Corporation Stock is not completed by
           April 30, 1991, then June 1, 1991), the assets of the fund shall be
           transferred to the MCN Stock Fund and the Primark Corporation Stock
           Fund shall cease to exist.  Each Participant shall be entitled to 
           direct the transfer of all or any portion of the amounts so



                                     -56-



<PAGE>   62

            transferred to the MCN Stock Fund on his or her behalf to any other
            fund or funds in accordance with, and subject to the limitations of
            section 7.3.
       (d)  Other Funds.  Such other funds offered by the Trustee as the
            Committee may select.
Notwithstanding the foregoing, the Trustee or the investment manager, as the
case may be, shall invest such portion of the assets of the funds as the
Committee may deem necessary or appropriate to facilitate the administration of
such funds in any short-term fixed income fund as may be established under any
common, commingled, or collective trust for employee benefit plans established
and maintained by the Trustee.

     7.2    Management of Investment Funds.  Except as otherwise provided in 
this Article VII, each fund shall be under the exclusive management and control 
of the Trustee; the ownership of the assets and investments of the funds shall
be in the Trustee as such; and the Trustee shall have in respect of any and all
assets of the funds the same powers as if it were absolute owner thereof.

     7.3    Voting of MCN Stock.
      (a)   Instructions from Participants.  The Trustee shall vote, in
            person or by proxy, shares of MCN Stock held by the Trustee in the
            MCN Stock fund in accordance with instructions obtained from
            Participants.

            Each Participant shall be entitled to give voting instructions with
            respect to the number of shares of such respective stock which
            bears the same ratio to the total number of shares held by the
            Trustee on the record date as the number of shares allocated to the
            respective stock fund account of such Participant as of the
            Valuation Date preceding such record date bears to
            the total number of shares allocated to the respective stock fund
            accounts of all Participants as of such



                                     -57-



<PAGE>   63

            Valuation Date, excluding shares allocated to the accounts of
            persons whose accounts have been distributed prior to such record
            date.

            Written notice of any meeting of stockholders of MCN Corporation
            and a request for voting instructions shall be given by the
            Committee or the Trustee, at such time and in such manner as the
            Committee shall determine, to each Participant entitled to give
            instructions for the voting of stock at such meeting.

            Shares with respect to which no voting instructions are received
            from Participants and unallocated shares of the ESOP shall be voted
            by the Trustee in the same proportion as shares for which voting
            instructions are received from Participants.  The Trustee shall
            combine and vote fractional shares to the extent possible to
            reflect the voting instructions of Participants.
       (b)  Confidentiality.  The instructions received by the Trustee
            from Participants shall be held by the Trustee in strict confidence
            and shall not be divulged or released to any person, including
            officers or employees of the Company or any Affiliated Company.

     7.4    Tender Offers.
      (a)   Rights of Participants.  Notwithstanding any other provisions
            of this instrument, in the event an offer is made generally to the
            shareholders of MCN Corporation to transfer all or a portion of the
            common stock of MCN Corporation in return for valuable consideration
            including, but not limited to, offers regulated by section 14(D) of
            the Securities Exchange Act of 1934, as amended, each Participant
            owning a beneficial interest in the MCN Stock fund shall have the
            sole and exclusive right to decide if the common stock representing 
            his interest in such fund shall be tendered.  Each Participant shall
            have the right, to



                                     -58-



<PAGE>   64

            the extent the terms of the tender offer so permit, to direct the
            withdrawal of such shares from tender.  A Participant shall not be
            limited as to the number of instructions to tender or withdraw from
            tender which he can give; provided, however, the Participant shall
            not have the right to give instructions to tender or withdraw from
            tender after a reasonable time established by the Trustee pursuant
            to section 7.4(c) below.
      (b)   Duties of the Committee.  Within a reasonable time after the
            commencement of a tender offer, the Committee shall provide to each
            Participant having an ownership interest in the MCN Stock fund--
            (1)  the offer to purchase as distributed by the
                 offeror to the shareholders of MCN Corporation,
            (2)  a statement of the shares representing his interest in the 
                 MCN Stock fund as of the most recent information available 
                 from the Committee, and
            (3)  directions as to the means by which a Participant can give 
                 confidential instructions to the Trustee with respect to the 
                 tender.  The Committee shall establish and pay for a means 
                 such as, but not limited to, Datagram by which a Participant 
                 can expeditiously deliver to the Trustee instructions with 
                 respect to the tender.
      (c)   Duties of the Trustee.  The Trustee shall follow the instructions 
            of the Participants with respect to the tender offer.
            The Trustee shall not tender shares for which no instructions are
            received.  Unallocated shares of MCN Stock of the ESOP shall be
            tendered or exchanged by the Trustee in the same proportion as the
            allocated shares for which the Trustee has received written
            direction are tendered or exchanged, subject to the terms of any 
            loan or pledge agreement covering such shares.  On the basis of its 
            ability to comply with the



                                     -59-



<PAGE>   65

           terms of the offer, the Trustee shall establish a reasonable time
           after which it shall not accept the instructions of Participants.
      (d)  Confidentiality.  The instructions received by the Trustee
           from Participants shall be held by the Trustee in strict confidence
           and shall not be divulged or released to any person, including
           officers or employees of the Company or any Affiliated Company.

     7.5   Named Fiduciary Status.  For purposes of sections 7.3 and 7.4, each
Participant is hereby designated a "named fiduciary" within the meaning of
ERISA section 403(a)(1) with respect to shares of MCN Stock as to which he is
entitled to make voting or tender offer decisions.

     7.6   Expenses of Funds.  Brokerage commissions, transfer taxes, and other
charges and expenses in connection with the purchase and sale of securities for
a fund shall be charged to the fund.  Any income and other taxes payable with
respect to a fund shall likewise be charged to the fund.

     7.7   Primark Corporation Stock.  The provisions of sections 7.3, 7.4, and
7.5 pertaining to MCN Stock shall also be applicable to Primark Corporation
Stock during the period of its existence.



                                     -60-



<PAGE>   66

     Article VIII.  Accounts and Records of the Plan


     8.1   Committee to Maintain Accounts.  The Committee shall maintain, or
cause to be maintained, for each Participant--
      (a)  a Savings Plan Account attributable to Voluntary Deduction
           allotments and related Employer contributions under section 4.2, and
      (b)  a separate account attributable to Salary Reduction
           allotments and related Employer contributions under section 4.2,
each of which shall be composed, to the extent required by the investment
directions of the particular Participant, of a MCN Stock fund account, a Fixed
Income fund account, and an account for each other applicable fund in which his
allotments and related contributions are invested.

The Committee also shall maintain, or cause to be maintained, for each
Participant--
      (c)  an ESOP Account attributable to Employer contributions under
           section 4.3(a) and (c), and
      (d)  shares of MCN Stock allocated to the Participant pursuant to
           section 14.4(d),
each of which shall be composed of a MCN Stock fund account and, to the extent
diversification elections are made by the Participant under section 14.5, such
other accounts as the Committee or its delegate deems necessary or appropriate
in giving effect to the diversification requirements of section 14.5.

The Committee shall maintain, or cause to be maintained, all necessary records.

     8.2 Plan Accounting.  The interests of each Participant in the funds shall
be his proportionate share of the value of such funds as of any Valuation Date.
The Participant's proportionate
share may be determined under any accounting method selected by the Committee
that allocates fairly, in the opinion of the



                                     -61-



<PAGE>   67
Committee, the investment gains and losses by or on behalf of each Participant
to the fund and that complies with the Code requirements of the Code and the
Regulations thereunder.  The value of Participants' fund accounts shall be
redetermined as of each Valuation Date.

     8.3 Valuation of Funds.  The value of a fund as of any Valuation Date
shall be the market value of all assets (including any uninvested cash) held by
the fund as determined by the Trustee reduced by the amount of any accrued
liabilities of the fund on such Valuation Date.  The Trustee's determination of
market value shall be binding and conclusive upon all parties.

     8.4 Valuation of Savings Plan Account.  The value of a Participant's
Savings Plan Account as of any Valuation Date shall be the sum of the values of
his MCN Stock fund account, Fixed Income fund account, and any other of his
fund accounts attributable to Salary Reductions, Voluntary Deductions, and
Employer Contributions under section 4.2.

     8.5 Valuation of ESOP Account.  The value of a Participant's ESOP Account
as of any Valuation Date shall be the sum of--
      (a)  the value of his MCN Stock fund account attributable to
           Employer contributions on his behalf under section 4.3(a) and (c)
           and shares of MCN Stock allocated to his ESOP Account under section
           14.4(d); and
      (b)  the sum of the values of his Fixed Income fund account and
           any other of his fund accounts attributable to diversification
           elections under section 14.5.

     8.6 Valuation of Plan Account.  The value of a Participant's Plan Account
as of any Valuation Date shall be the sum of the values of his MCN Stock fund
account, Fixed Income fund account, and any other investment fund accounts
maintained on his behalf under the Plan.

        

                                     -62-



<PAGE>   68
     8.7 Committee to Furnish Annual Statements of Value of Plan Accounts.  The
Committee shall, not less frequently than annually, distribute to each
Participant in the Plan a statement setting forth the Plan Account of such
Participant.  Such statement shall be deemed to have been accepted as correct
unless written notice of objections thereto is received by the Committee or the
Employer within 30 days after the distribution of such statement to the
Participant.

     8.8 Trust Agreement.  A Trust has been established to fund benefits under
the Plan.  The Employers may, without further reference to or action by any
Employee or Participant, from time to time enter into further agreements with
the Trustee and make such amendments to such Trust Agreement or such further
agreements as they may deem necessary or desirable to carry out the Plan, and
may take such other steps and execute such other instruments as the Employers
may deem necessary or desirable to put the Plan into effect or to carry it out.



                                     -63-



<PAGE>   69
               Article IX.  Distributions, Withdrawals, and Loans

     9.1 Distribution Upon Termination of Employment Entitling Participant to
Value of Plan Account.  Upon termination of a Participant's employment with his
Employer--
      (a)  due to retirement on his Normal Retirement Date, his Early
           Retirement Date, or his Disability Retirement Date,
      (b)  by the death of the Participant,
      (c)  because of total and permanent disability or legally
           established mental incompetency of the Participant not qualifying
           the Participant for retirement pursuant to section 2.1(o), or
      (d)  under any circumstances after the Participant has satisfied
           the Vesting Requirement,
the Committee shall, subject to the provisions of section 9.7, direct the
Trustee to distribute to the Participant, or, in a proper case his designated
beneficiary or legal representative, the value of the Participant's Plan
Account as of the Valuation Date coincident with or next following the date of
termination of employment.

Notwithstanding the foregoing, the value of a Participant's Plan Account shall
become nonforfeitable as of the date on which the Participant attains his
sixty-fifth birthday, provided he is an Employee on that date.

     9.2 Distribution Upon Termination of Employment Under Circumstances
Resulting in Forfeiture of Employer Contributions.  Upon termination of a
Participant's employment under circumstances other than those described in
sections 9.1 and 9.7(c)(2), the Committee shall, subject to the provisions of
section 9.7, direct the Trustee to distribute to the Participant an amount
equal to the value of the Participant's Employee Pre-1987 Voluntary Deduction
Account, Employee Post-1986 Voluntary Deduction Account, and Employee Salary
Reduction Account each of which shall be fully vested and nonforfeitable at all
times.  The
        


                                     -64-



<PAGE>   70

Participant's Employer Voluntary Deduction Account, Employer Salary Reduction
Account, and ESOP Account shall be forfeited and applied in reduction of the
next succeeding contribution which the Participant's Employer would otherwise
contribute to the Trust; provided, however--
      (a)  If all or any portion of such account is vested as a result
           of the application of the accelerated vesting schedule set forth in
           section 13.4(d), the Committee shall direct the Trustee to
           distribute such portion to the Participant; and
      (b)  If such Participant is reemployed prior to his incurring five
           consecutive Break in Service Years, then as of the Valuation Date
           coincident with or next following his date of reemployment, the
           Participant's Employer shall contribute on behalf of such
           Participant an amount equal to the amount that was forfeited upon
           his termination of employment, and such contribution shall be
           credited to the same accounts from which it was forfeited, in the
           same amounts, except amounts that would otherwise be credited to the
           Primark Corporation Stock fund shall be credited to the MCN Stock
           fund.
Contributions made pursuant to (b) shall not be taken into account in
determining under section 4.13 the Annual Additions to such Participant's
Savings Plan Account.

     9.3   Certain Distributions from Participant Accounts.
      (a)  In General.  Any Participant may, upon 20 days' written notice 
           to the Committee in the form prescribed by the Committee,
           terminate his participation in the Plan as of any Valuation Date.
           Upon such termination, the Committee shall direct the Trustee to
           distribute to the Participant an amount equal to the value of the
           Participant's Employee Pre-1987 Voluntary Deduction Account and
           Employee Post-1986 Voluntary Deduction Account.  Such a Participant
           shall continue to be considered a Participant for all purposes of 
           the Plan



                                     -65-



<PAGE>   71
            except for purposes of Article IV (Contributions), but shall be
            ineligible to again elect to make allotments under the Plan for a
            period of 12 full Accounting Periods from the date of termination
            of his participation.
      (b)   Withdrawals After Age 59 1/2.
            (1)  Prior to January 25, 1991, upon 20 days' written
                 notice to the Committee in the form prescribed by the
                 Committee, any Participant who has satisfied the Vesting
                 Requirement and attained age 59 1/2 may terminate his
                 participation in the Plan as of any Valuation Date.  Upon such
                 termination, the Committee shall direct the Trustee to
                 distribute to the Participant the value of his Plan Account as
                 of such Valuation Date and such Participant shall be
                 ineligible to again elect to make allotments under the Plan
                 for a period of 12 full Accounting Periods from the date of
                 termination of participation.
            (2)  Effective January 25, 1991, upon 20 days' written
                 notice to the Committee in the form prescribed by the
                 Committee, any Participant who has attained age 59 1/2 may
                 make an election, not more frequently than--
                 (A)  prior to December 1, 1993, once in any 12-month period, or
                 (B)  on or after December 1, 1993, once every calendar year,
                 to withdraw all or any portion of the vested amount of his
                 Plan Account as of any Valuation Date.  Upon such withdrawal,
                 the Committee shall direct the Trustee to distribute to the
                 Participant as of such Valuation Date the amount the
                 Participant has elected to withdraw.
      (c)  Limited Withdrawal in the Event of Hardship.  Effective
           January 25, 1991, if a Participant incurs a financial hardship as
           defined in section 9.6, he may limit the



                                     -66-



<PAGE>   72
            amount of a distribution from his Voluntary Deduction Account under
            section 9.3(a) to the amount necessary to satisfy the hardship and
            to pay any taxes resulting from such distribution.

     9.4 In-Service Withdrawals--General.  At its discretion, the Committee may
adopt rules limiting the number of withdrawals that may be made in any Plan
Year and prescribe a minimum amount that may be withdrawn.  All requests for a
withdrawal shall be submitted in a form prescribed by the Committee.  A
Participant may not rescind a request for withdrawal which has been submitted
to the Committee unless the Committee consents.  A withdrawal shall be
distributed as soon as reasonably practicable after the withdrawal request is
received.

     9.5 Withdrawal of Voluntary Deduction Allotments.  Any Participant who
shall have actively participated in the Plan for 24 or more calendar months
(for purposes of this section 9.5 active participation means the Participant
shall have made allotments to the Plan in each month in which compensation was
available), including months in which the Participant made allotments under the
Michigan Consolidated Gas Company Employees' Savings Plan, may, upon 20 days'
written notice to the Committee, withdraw as of any Valuation Date an amount
not in excess of 100 percent of his Voluntary Deduction allotments under the
Plan; provided, however, that the amount withdrawn shall in no event exceed the
sum of the values of his Employee Pre-1987 Voluntary Deduction Account and
Employee Post-1986 Voluntary Deduction Account invested in the MCN Stock fund,
the Fixed Income fund, and any other investment funds under the Plan as of such
Valuation Date.  Successive withdrawals may be made at intervals of not less
than two full years provided that the total amount withdrawn may never exceed
the limitations prescribed in the preceding sentence.

Withdrawals under this section 9.5 shall be from the MCN Stock fund, the Fixed
Income fund, or such other investment funds



                                     -67-



<PAGE>   73
offered by the Trustee as the Committee shall make available for purposes of
this section.  If the Participant has an account in more than one fund, he
shall specify in his written direction to the Committee the amount to be
withdrawn from each fund.  The allotments in all funds in the Employee Pre-1987
Voluntary Deduction Account must be withdrawn before a withdrawal is permitted
from a fund in the Employee Post-1986 Voluntary Deduction Account.  The amount
of an in-service withdrawal from a specific fund in a Voluntary Deduction
Account shall not exceed the Employee's allotments in such fund prior to the
withdrawal.

     9.6 Hardship Withdrawal of Salary Reduction Allotments.  A Participant may
request, upon 20 days' written notice to the Committee, a withdrawal from his
Salary Reduction Account if the withdrawal is necessary to satisfy an immediate
and heavy financial need of a Participant as defined below.  The amount of such
withdrawal shall be limited to the Participant's Salary Reduction allotments or
the total value of the Participant's Employee Salary Reduction Account as of
the latest Valuation Date for which information is available, whichever is
smaller.  Withdrawals under this section 9.6 shall be from the MCN Stock fund,
the Fixed Income fund, or such other investment funds under the Plan as the
Participant specifies in his written request for a hardship withdrawal.

The determination of whether or not a distribution is necessary to satisfy an
immediate and heavy financial need and the amount required to be distributed to
meet the need shall be made by the Committee.  All determinations regarding
financial need shall be made in accordance with written procedures established
by the Committee and applied in a uniform and nondiscriminatory manner.
Such written procedures shall specify the requirements for requesting and
receiving distributions on account of financial need, including the forms that
must be submitted and to whom the forms are to be submitted.  All determinations
regarding financial need must comply with applicable Regulations under the Code.
        
        

                                     -68-



<PAGE>   74

For purposes of this section 9.6, a financial hardship withdrawal shall be
limited to the amount required to meet the need created by one of the following
situations:
      (a)  Expenses for medical care described in Code section 213(d)
           previously incurred by the Participant, his spouse, or any
           dependents of the Participant or necessary for these persons to
           obtain medical care described in Code section 213(d).
      (b)  Costs directly related to the purchase (excluding mortgage
           payments) of the principal residence for the Participant.
      (c)  Payment of tuition and related educational fees for the next
           12 months of post-secondary education for the Participant, his
           spouse, children, or dependents (as defined in Code section 152).
      (d)  The need to prevent the eviction of the Participant from his
           principal residence or foreclosure on the mortgage on the
           Participant's principal residence.
A distribution will be deemed necessary to satisfy an immediate and heavy
financial need of a Participant only if both of the following conditions are
met:
      (1)  The distribution is not in excess of the amount of the immediate 
           and heavy financial need of the Participant.  Effective January 1, 
           1993, this amount may be increased by the lesser of the amount 
           withheld from the distribution under Code section 3405(c), as
           enacted by section 522(b) of the Unemployment Compensation
           Amendments of 1992, Public Law No. 102-318, Stat. 290 or remaining
           Salary Reduction allotments or total value of the Salary Reduction
           Account, if less, after subtracting the amount of the immediate and
           heavy financial need.
      (2)  The Participant has obtained all distributions, other than hardship
           distributions, and all loans available under this Plan and all 
           other plans maintained by the Employer.



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<PAGE>   75


If a Participant receives a hardship distribution, (A) the Participant shall
not be entitled to make Salary Reduction allotments or Voluntary Deduction
allotments for a period of one year after the hardship distribution, and (B)
the Participant may not make Salary Reduction allotments for the Participant's
taxable year immediately following the taxable year of the hardship
distribution in excess of the amount specified in Code section 402(g) for such
taxable year less the amount of the Participant's Salary Reduction allotments
for the taxable year of the hardship distribution.

     9.7   Time of Distributions.
      (a)  In General.  Except as hereinafter provided and subject to
           the provisions of section 9.9, distributions made pursuant to
           section 9.1 or 9.7(c)(2) shall be made by the Trustee at the
           direction of the Committee on such date as the Committee shall
           determine after consultation with the Participant or his
           beneficiary, but in no event later than March 1 of the calendar year
           following termination of the Participant's employment.

           Except as hereinafter provided, all other distributions or
           withdrawals under this Article IX shall be paid as soon as
           reasonably practicable by the Trustee at the direction of the
           Committee after the applicable Valuation Date.  Notwithstanding any
           other provision of the Plan--
           (1)   if the vested portion of a Participant's Plan Account exceeds
                 $3,500, no distribution shall be made to such Participant 
                 pursuant to section 9.1, 9.2, 9.7(c)(2), or 9.9 prior to the 
                 date the Participant attains the age of 65 without written 
                 consent of the Participant; and
           (2)   if a distribution to a Participant is deferred pursuant to 
                 (1), the amount that would otherwise have been distributed to 
                 such Participant shall be invested--



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<PAGE>   76

                  (A)  prior to August 1, 1991, in the Fixed Income fund, and
                  (B)  on and after August 1, 1991, in the Fixed Income fund 
                       or any other investment fund under the Plan, as the 
                       Participant shall direct, 
                  except that the ESOP Account of such Participant shall
                  continue to be invested in the MCN Stock fund, subject to the
                  diversification rules set forth in section 14.5.
            As soon as practicable after April 30, 1990, the Committee shall
            direct the Trustee to transfer from the Fixed Income fund to the
            MCN Stock fund, on behalf of each former Participant who terminated
            employment on or after April 1, 1989 and prior to the date of
            adoption of the Second Amendment, and whose distribution has been
            deferred, an amount equal to the sum of (A) the amount required to
            purchase the number of shares of MCN Stock credited to his or her
            ESOP Account immediately prior to his or her termination of
            employment, plus (B) the amount of dividends that would have been
            credited thereon from April 1, 1989 to the date of such transfer.
            Such amount shall be credited to the ESOP Account of such former
            Participant.

            A former Participant whose distribution has been deferred pursuant
            to (1) above will not thereafter be eligible for withdrawals under
            section 9.3 or 9.5 or loans under section 9.10 but shall continue
            to have the voting and tender offer rights described sections 7.3
            and 7.4 and to be treated as a Participant for purposes of Article
            VIII.

            A former Participant whose distribution has been deferred may
            initiate a distribution upon 30 days' prior written notice to the
            Committee and shall receive an amount equal to the vested portion
            of his Plan



                                     -71-



<PAGE>   77
            Account as of the Valuation Date next following the expiration of
            such 30-day period, with such amount to be distributed in a lump
            sum cash payment except that--
            (i)  amounts invested in the MCN Stock fund shall be distributed 
                 in accordance with section 9.8,
           (ii)  effective as of August 1, 1991, such former Participant may 
                 upon 30 days' prior notice to the Committee receive a partial
                 distribution rather than a total distribution, of the vested 
                 portion of his Account, but not more frequently than once in 
                 any calendar year (prior to December 1, 1993, not more 
                 frequently than once in any 12-month period), and
          (iii)  to the extent that such distribution comes from the Fixed 
                 Income fund account, such distribution shall be subject to
                 the provisions of section 9.9.
            Notwithstanding any other provision of this Plan, if a Participant
            attains age 70 1/2 and still has a balance allocated to his or her
            Plan Account, a distribution shall be made under section 9.1 as if
            the Participant had terminated employment in the month in which the
            Participant attains age 70 1/2.  Such distribution shall in no
            event be later than April 1 of the calendar year following the year
            in which the Participant attains age 70 1/2.  Distributions to such
            Participant shall be made annually thereafter no later than April 1
            of each year and shall be equal to at least the minimum amount
            required to be distributed by Code section 401(a)(9).  For purposes
            of this paragraph, the life expectancy of a Participant and the
            Participant's spouse shall be redetermined annually.
      (b)   Suspension of Participation.  If a Participant shall, prior
            to termination of his employment, cease to meet the eligibility
            requirements of the Plan, his allotments and Employer contributions
            on his behalf shall be suspended during the period of his 
            ineligibility.  Subject to section 3.1, distribution of



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<PAGE>   78

            such Participant's Plan Account shall be deferred until termination
            of his employment with the Company and any Affiliated Company.  If
            the provisions of section 3.3 relating to the transfer of a
            Participant's Plan Account to the Michigan Consolidated Gas Company
            Union Employees' Investment Plan or its successor are not
            applicable--
            (1)  with respect to Participants who cease to meet
                 the eligibility requirements of the Plan prior to January 1,
                 1987, the Committee shall direct the Trustee to distribute the
                 value of the Participant's Plan Account in accordance with
                 section 9.1 whether or not such termination of employment
                 shall be under the circumstances set forth in said section
                 9.1; and
            (2)  with respect to Participants who cease to meet the eligibility 
                 requirements of the Plan subsequent to December 31, 1986, such 
                 distribution shall be in accordance with section 9.1 or 9.3, 
                 whichever is applicable.
      (c)   Transfer of Employment.
            (1)  A transfer of employment from an Employer to an Affiliated 
                 Company shall not be considered a termination of employment.
            (2)  If a Participant shall be transferred to the employ of an 
                 Affiliated Company which has not elected to participate in 
                 the Plan, distribution of such Participant's Plan Account 
                 shall be deferred until the date on which he is no longer in 
                 the employ of the Company or any Affiliated Company, whereupon 
                 the Committee shall direct the Trustee to distribute the 
                 value of the Participant's Plan Account in the manner 
                 prescribed in section 9.1, subject to the provisions of 
                 section  9.7, whether or not termination of employment shall 
                 be under circumstances set forth in said section 9.1.



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<PAGE>   79

      (d)  Special Rules Relating to Distributions in the Event of
           Death.  In the event that a Participant dies before a distribution
           of his Plan Account, the Committee shall direct the Trustee to
           distribute the entire value of his Plan Account to his beneficiary
           no later than March 1 of the calendar year following the
           Participant's death, as provided in section 9.1.  In the event of
           the death of the Participant after the distribution of his Plan
           Account has begun, any remaining balance in his Plan Account at the
           time of death will be distributed at least as rapidly as under the
           method of distribution in effect at the date of the Participant's
           death.

     9.8 Distributions of Stock.  In the case of distributions under section
9.1, 9.2, 9.3(b), 9.7(a), or 9.7(c)(2), the value of the Participant's MCN
Stock and/or Primark Corporation Stock fund account(s), if any, shall be paid
in full shares of stock except that cash shall be distributed in lieu of
fractional shares; provided, however, that a Participant entitled to such a
distribution may elect to receive cash in lieu of MCN Stock and/or Primark
Corporation Stock.  Except in the case of an election to receive cash in lieu
of MCN Stock and/or Primark Corporation Stock--
      (a)  prior to August 1, 1991, the number of shares to be
           distributed from such account shall be the quotient of the value of
           such account as of the applicable Valuation Date divided by the
           value assigned by the Trustee to a share of MCN Stock or Primark
           Corporation stock for purposes of valuing the fund as of such
           Valuation Date; and
      (b)  on and after August 1, 1991, the total number of shares
           allocated to such account shall be distributed from such account.
Any remaining value of such account and, subject to the provisions of section
9.9, the value of the Participant's accounts in other funds shall be
distributed in cash.  Any



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<PAGE>   80
transfer taxes payable with respect to the distribution of shares of stock
shall be charged to the respective MCN Stock or Primark Corporation Stock fund.
Distributions pursuant to section 9.3(a) and withdrawals under sections 9.5
and 9.6 shall be paid entirely in cash.

     9.9   Distributions from Fixed Income Fund.
      (a)  Normal Form.  Notwithstanding any provision of the Plan,
           other than the final paragraph of section 9.7(a), if a distribution
           is to be made under section 9.1(a) or (c) and the Participant has a
           Fixed Income fund account and at least one Hour of Employment prior
           to May 31, 1988, then unless the Participant or legal representative
           shall make an election in the manner prescribed in section 9.9(b),
           the value of such account (exclusive of the portion thereof
           attributable to diversification elections under section 14.5) shall
           be distributed by the purchase of a single premium annuity contract
           providing for monthly payments during the Participant's lifetime
           and, if the Participant is married on the date payment of his
           benefit commences and his spouse shall survive him, for monthly
           payments during the remainder of such spouse's lifetime, each such
           payment to such spouse being equal to one-half of the monthly
           payment received by the Participant, commencing no later than March
           1 of the calendar year following the calendar year of the
           Participant's termination of employment, and delivery of such
           contract to the Participant within a reasonable time after the
           Participant's termination of employment.

           If a distribution is to be made under section 9.1(b) because of a
           Participant's death and the Participant had a Fixed Income fund
           account at the time of his death and at least one Hour of 
           Employment prior to May 31, 1988, then unless the Participant had 
           made or the Participant's spouse or beneficiary, as the case



                                     -75-



<PAGE>   81
            may be, makes an election at the time and in the manner prescribed
            in section 9.9(b), the value of the Participant's Fixed Income fund
            account (exclusive of the portion thereof attributable to
            diversification elections under section 14.5) shall be distributed
            by purchase of a single premium annuity contract providing for
            monthly payments to the Participant's spouse, or, if the
            Participant was not married on the day of his death, to his
            beneficiary during such person's lifetime, commencing no later than
            March 1 of the calendar year following the calendar year of the
            Participant's death and delivery of such contract to such person
            within a reasonable time after the date of Participant's death.
      (b)   Election to Reject Normal Form.  Subject to the provisions of
            this section 9.9(b), each Participant entitled to a distribution
            under section 9.9(a) (or legal representative on behalf of such a
            Participant) may, at any time during the 90-day period ending on the
            annuity starting date, elect to have the value of the Participant's
            Fixed Income fund account (exclusive of the portion thereof
            attributable to diversification elections under section 14.5)
            distributed by one or more of the methods set forth in section
            9.9(c).

            Within 30 days after a Participant provides written notice to the
            Committee of his intention to retire on his Early Retirement Date,
            Normal Retirement Date, or Disability Retirement Date, or within 30
            days after the Committee receives notice of a Participant's death,
            or within five business days after determining, pursuant to section
            2.1(o), that a Participant is totally and permanently disabled, or
            within five business days after receiving notice of the legally
            established mental incompetency of the Participant, if the 
            Participant has a Fixed Income fund account at such time, the 
            Committee shall deliver to such Participant



                                     -76-



<PAGE>   82

            or his legal representative, by mail or by personal delivery,
            written notice in nontechnical language explaining the terms and
            conditions of the annuity provided in section 9.9(a).

            The notice shall explain the Participant's or legal 
            representative's right to elect an optional form of distribution
            and that such election may be revoked by the Participant or legal
            representative at any time prior to the annuity starting date or,
            if a lump sum payment is elected, prior to the first day on which
            all events have occurred which entitle the Participant or legal
            representative to the lump sum payment.

            The notice shall explain that a married Participant may elect a
            distribution pursuant to section 9.9(c) only if the spouse consents
            in writing to such election.  Such written consent shall
            acknowledge consent to the designated beneficiary and the optional
            form of distribution, neither of which may be changed thereafter
            without again obtaining written spousal consent (or the consent of
            the spouse expressly permits changes by the Participant without
            further consent by the spouse).  Such written consent shall
            acknowledge the effect of such election and shall be witnessed by a
            notary public or by a representative of the Committee who is
            designated to act in such capacity by the Committee.

            If the Participant establishes to the satisfaction of the Committee
            that such written consent cannot be obtained because his spouse
            cannot be located, the requirement of such written consent shall be
            waived. Any election, change, or revocation under this section
            9.9(b) shall be effective when written notice is delivered to the
            Committee in a form approved by the Committee for this purpose,
            provided such election,



                                     -77-



<PAGE>   83

           change, or revocation is delivered prior to the annuity starting
           date or, if a lump sum payment is elected, prior to the first day
           on which all events have occurred which entitle the Participant or
           legal representative to the lump sum payment.  The notice shall
           explain that an effective revocation shall result in the benefit
           being provided as an annuity described in section 9.9(a).
      (c)  Optional Forms.  In addition to the form described in section
           9.9(a), distribution of the value of a Participant's Fixed Income
           fund account (exclusive of the portion thereof attributable to
           diversification elections under section 14.5) may be made either--
           (1)   in a lump sum payment no later than March 1 of
                 the calendar year following the calendar year of the
                 Participant's termination of employment or death; or
           (2)   by purchase of any form of single premium annuity
                 contract that satisfies Code section 401(a)(9) as may from
                 time to time be offered by the legal reserve life insurance
                 companies with which the Trustee has agreements governing the
                 investment of assets in the Fixed Income fund and delivery of
                 such contract to the Participant or distributee within a
                 reasonable time after the Participant's termination of
                 employment or death.  Within five business days after the
                 Committee receives an election pursuant to this provision, the
                 Committee shall provide the same written notice provided under
                 section 9.9(b).  An election pursuant to this provision shall
                 be subject to the provisions of section 9.9(b).

     9.10 Loans.  The Trustee is hereby authorized to establish a loan program
in accordance with this section 9.10.  Upon application of a party in interest
(as defined in ERISA section 3(14)) who is a Participant or beneficiary under 
the Plan, the



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<PAGE>   84

Committee shall direct the Trustee to make a cash loan to such Participant or
beneficiary, secured by 50 percent of the nonforfeitable value of the
Participant's Employee and Employer Salary Reduction and ESOP Accounts
determined as of the date the loan is made.  The loan program shall be
administered by the Committee subject to the following conditions and such
other conditions that are consistent with Labor Regulation section 2550.408b-1
and are from time to time set forth in a written document, delivered to
Participants and beneficiaries who are parties in interest (which document may
but need not be the Summary Plan Description), which provisions shall
constitute a part of the Plan and are hereby incorporated by reference:
      (a)  Effective October 18, 1989, the term of a loan shall not
           extend beyond the earlier of four years or the date upon which the
           Participant or beneficiary ceases to be a party in interest;
           provided, however, that the four years shall be changed to eight
           years where the proceeds of the loan are used by the Participant or
           beneficiary to acquire the Participant's principal residence.
      (b)  Effective October 18, 1989, a loan shall bear interest at a
           reasonable rate which shall be based upon the prevailing interest
           rate charged by persons in the business of lending money on similar
           commercial loans under comparable circumstances at the time that
           such loan is granted, as determined by the Committee and uniformly
           applied.
      (c)  Effective October 18, 1989, the amount of a loan (when added
           to the balance of other outstanding loans) shall not exceed the
           lesser of--
           (1) $50,000 reduced by the excess (if any) of--
                  (A)  the highest outstanding balance of loans from the Plan 
                       during the one-year period ending on the day before the 
                       date on which such loan was made, over
                  (B)  the outstanding balance of loans outstanding on the 
                       date such loan was made, or



                                     -79-



<PAGE>   85

            (2)  50 percent of the nonforfeitable value of the Participant's 
                 Employee and Employer Salary Reduction and ESOP Accounts 
                 under the Plan which the Participant would have been
                 entitled to receive if the Participant's employment had
                 terminated on the date such loan was made.
           In no case shall a Participant be entitled to a loan under this
           Plan if the amount of the proposed loan is less than $500.
      (d)  A loan shall be evidenced by a promissory note.
      (e)  Effective October 18, 1989, payments of principal and
           interest shall be made by approximately equal payments not less
           frequently than monthly on a basis that would permit the loan to be
           fully amortized over its term.  Loan payments shall be made by
           payroll deductions for Participants in active pay status.
      (f)  Appropriate disclosure shall be made pursuant to the Truth in
           Lending Act to the extent applicable.
      (g)  Amounts of principal and interest received on a loan shall be
           credited to the Participant's account and the outstanding loan
           balance shall be considered an investment of the assets of the
           account.  Payment of principal and interest shall be credited to the
           investment funds in the same proportion as the amount distributed
           from the funds from which the loan was granted to the Participant,
           except amounts that would otherwise be credited to the Primark
           Corporation Stock fund shall be credited to the MCN Stock fund.
      (h)  The frequency of loans and the minimum amount for a loan
           shall be determined through uniform rules prescribed by the
           Committee and at the sole discretion of the Committee.
      (i)  All applications for a loan shall be submitted to the Committee on 
           a form prescribed by the Committee.  Distribution shall be made as 
           soon as reasonably practicable after the application of the loan is
           received.



                                     -80-



<PAGE>   86

      (j)  If a Participant borrows from an account which is invested in
           more than one fund, he shall instruct the Committee as to the funds
           from which the loan is to be applied; provided, however, that no
           borrowing shall be applied from the MCN Stock fund unless and until
           the Participant's ability to borrow from each of the other funds has
           been exhausted.
      (k)  A married Participant may not borrow any amount from the Plan
           unless his spouse executes a written consent as hereinafter
           provided.  Such consent must be executed during the 90-day period
           ending on the date on which the loan is made and shall specifically
           provide that the spouse consents both to the loan and to the use of
           the Participant's Salary Reduction and ESOP Accounts as security for
           the loan.  The consent shall acknowledge the effect of the use of
           the Participant's accounts as security for the loan and shall be
           witnessed by a notary public or a representative of the Committee
           who is designated to act in such capacity by the Committee.
      (l)  In the event a Participant defaults on a loan, the entire
           outstanding balance of and accrued interest on the loan shall be due
           and payable.  The Trustee and/or Committee may pursue collection on
           such defaulted loan by any means generally available to a creditor
           where a promissory note is in default, or if the entire amount due
           is not paid by such Participant following the default, the amount of
           such loan default shall be charged against the "secured portion" of
           the Participant's Plan Account and treated as a distribution with
           respect to such Participant; provided, however, that such a charge
           against a Participant's Plan Account shall not occur with respect to
           funds in his Employee Salary Reduction Account at a time so as to
           cause a violation of Code section 401(k)(2)(B)(i).


                                    -81-


<PAGE>   87


     9.11 Definition of Allotments and Employer Contributions. For the purposes
of this Article IX, a Participant's allotments shall include only those
allotments made either as a Voluntary Deduction or a Salary Reduction which
have not been previously withdrawn or distributed.

If a Participant has previously had a portion of his Plan Account forfeited
under section 9.2, the Employer contributions, exclusive of those made as a
Salary Reduction to the Plan on his behalf, shall include only such Employer
contributions made subsequent to such forfeiture.

     9.12 Spousal Consent to Payment.  Subject to section 9.7(a), the spouse of
a married Participant or former Participant shall be required to consent in
writing to any in-service withdrawal, loan, or distribution under the Plan to
the Participant or former Participant; provided, however, for distributions on
account of termination of employment, this sentence shall be effective as of
January 1, 1993.  The spouse's consent shall be in such form as the Committee
may prescribe.

     9.13 Distributions Pursuant to a Qualified Domestic Relations Order.  Upon
receipt of a domestic relations order, the Committee will notify the involved
Participant and any alternate payee that the order has been received and
explain the Plan's procedures for determining whether the order is a qualified
domestic relations order as defined in Code section 414(p).  After determining
that the order is a qualified domestic relations order, the Committee shall
direct the Trustee to distribute or segregate the Participant's Account as
provided in the qualified domestic relations order.  If required by the
qualified domestic relations order, the Trustee shall make distribution prior
to the time that the Participant, whose account is subject to distribution,
could have received a distribution.



                                     -82-



<PAGE>   88

In a case of a dispute regarding the validity of a domestic relations order or
the amounts or identities of parties to be paid thereunder, the Committee may
segregate the portion of the Participant's account in question, and may bring
an action in a court of competent jurisdiction to determine the proper amount
and/or recipient of benefits, or may submit such segregated amount to a court
of competent jurisdiction (through an interpleader action or otherwise) until
resolution of the matter.

Further, if the Committee receives notice that a domestic relations order is
forthcoming, the Committee may suspend payments from the Participant's Account
or may follow the procedures described in the preceding sentence, until
resolution of the matter.

     9.14  Direct Rollovers of Eligible Distributions.
      (a)  General.  This section applies to distributions made on or
           after January 1, 1993.  Notwithstanding any provision of the Plan to
           the contrary that would otherwise limit a distributee's election
           under this section, a distributee may elect, at the time and in the
           manner prescribed by the Committee, to have any portion of an
           eligible rollover distribution paid directly to an eligible
           retirement plan specified by the distributee in a direct rollover.
      (b)  Definitions.
           (1)   Eligible rollover distribution.  An eligible rollover 
                 distribution is any distribution of all or any portion of the 
                 balance to the credit of the distributee, except that an 
                 eligible rollover distribution does not include: any 
                 distribution that is one of a series of substantially equal 
                 periodic payments (not less frequently than annually) made 
                 for the life (or life expectancy) of the distributee or the 
                 joint lives (or joint life expectancies) of the distributee 
                 and the distributee's designated beneficiary, or for a



                                     -83-



<PAGE>   89

                 specified period of ten years or more; any distribution to
                 the extent such distribution is required under Code section
                 401(a)(9); and the portion of any distribution that is not
                 includible in gross income (determined without regard to the
                 exclusion for net unrealized appreciation with respect to
                 employer securities).
            (2)  Eligible retirement plan.  An eligible retirement
                 plan is an individual retirement account described in Code
                 section 408(a), an individual retirement annuity described in
                 Code section 408(b), an annuity plan described in Code section
                 403(a), or a qualified trust described in Code section 401(a),
                 that accepts the distributee's eligible rollover distribution.
                 However, in the case of an eligible rollover distribution to
                 the surviving spouse, an eligible retirement plan is an
                 individual retirement account or individual retirement
                 annuity.
            (3)  Distributee.  A distributee includes an Employee
                 or former Employee.  In addition, the Employee's or former
                 Employee's surviving spouse and the Employee's or former
                 Employee's spouse or former spouse who is the alternate payee
                 under a qualified domestic relations order, as defined in Code
                 section 414(p), are distributees with regard to the interest
                 of the spouse or former spouse.
            (4)  Direct rollover.  A direct rollover is a payment
                 by the Plan to the eligible retirement plan specified by the
                 distributee.
      (c)  Waiver of 30-Day Notice Period.  If a distribution is one to
           which Code sections 401(a)(ll) and 417 do not apply, such
           distribution may commence less than 30 days after the notice 
           required under section 1.411(a)-11(c) of the Income Tax Regulations
           is given, provided that:
           (1)  the Committee clearly informs the Participant that the 
                Participant has a right to a period of at



                                     -84-



<PAGE>   90
                 least 30 days after receiving the notice to consider the
                 decision of whether or not to elect a distribution (and, if
                 applicable, a particular distribution option), and
            (2)  the Participant, after receiving the notice, affirmatively 
                 elects a distribution.











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<PAGE>   91
                                                                    SAVINGS PLAN


                           Article X.  Administration

     10.1  The Savings and Stock Ownership Plan Committee.
      (a)  The Employers shall appoint a Committee consisting of at
           least three members which shall be known as the Savings and Stock
           Ownership Plan Committee (the "Committee") and which shall be
           responsible (except for duties specifically vested in the Trustee)
           for the administration of the provisions of the Plan.
      (b)  Each Employer may have at least one representative on the
           Committee who shall be appointed by and remain in the office at the
           will of such Employer.  Each Employer shall have the right at any
           time, with or without cause, to remove its representative on the
           Committee.  A member of the Committee may resign and his resignation
           shall be effective upon delivery of his written resignation to each
           Employer.  Upon resignation, removal, or failure or inability for
           any reason of any member of the Committee to act hereunder, the
           Board of Directors of the Employer by whom such member was appointed
           shall appoint a successor member.  All successor members of the
           Committee shall have all of the rights and privileges and all of the
           duties of their predecessors but shall not be held accountable for
           the acts of their predecessors.  Two or more Employers may appoint
           the same individual as their representative on the Committee,
           provided that the Committee shall consist of at least three members.
      (c)  Any member of the Committee may, but need not, be a Participant or 
           a director, officer, or shareholder of any of the Employers, and 
           such status shall not disqualify him from taking any action 
           hereunder or render him accountable for any distribution or
           material advantage received by him under the Plan, provided that
           no member of the Committee who is a Participant shall take part in
           any action of the Committee on any matter involving solely his
           rights under the Plan.



                                     -86-



<PAGE>   92

      (d)  The Committee shall be responsible for the administration of
           the Plan.  The Committee shall have all such powers as may be
           necessary to carry out the provisions of the Plan and may from time
           to time establish rules and procedures for the administration of the
           Plan and the transaction of the Plan's business.

           The Committee shall have the exclusive right to make any finding of
           fact necessary or appropriate for any purpose under the Plan.  The
           Committee shall have the maximum discretion permitted by law to
           interpret and construe the terms of the Plan and to resolve all
           issues arising under the Plan including, but not limited to the
           authority to--
           (1)  construe disputed or doubtful terms of the Plan;
           (2)  determine the eligibility of an individual to participate in 
                the Plan;
           (3)  determine the amount, if any, of benefits to which any 
                Participant, former Participant, beneficiary, or other person 
                may be entitled under the Plan;
           (4)  determine the timing and manner of payment of benefits; and
           (5)  resolve all other issues arising under the Plan.
           To the extent permitted by law, all findings of fact,
           determinations, interpretations, and decisions of the Committee
           shall be conclusive and binding upon all persons having or claiming
           to have any interest or right under the Plan.

           The Employers shall, from time to time, on request of the
           Committee, furnish to the Committee such data and information as
           the Committee shall require in the performance of its duties.

      (e)  The Committee shall each month collect Employee allotments
           and Employer contributions from each Employer and shall deliver the
           amounts collected to the



                                     -87-



<PAGE>   93
           Trustee, together with instructions concerning the portions of such
           total amount to be invested in each fund.
      (f)  The Committee shall direct the Trustee to make payments of
           amounts to be distributed or withdrawn from the Trust under Article
           IX and to make any transfers from one fund to another directed by
           Participants under section 6.3.
      (g)  The Committee may act at a meeting, or by writing without a
           meeting, by the vote or assent of a majority of its members.  The
           Committee shall elect a Secretary and such Secretary shall keep
           records of all meetings of the Committee and shall forward all
           necessary communications to the Trustee.  The Committee may adopt
           such by-laws and regulations as it deems desirable for the conduct
           of its affairs and the administration of the Plan, provided that any
           such regulations shall be consistent with the provisions of the
           Plan.
      (h)  The members of the Committee, and each of them, shall be free
           from all liability, joint or several, for their acts, omissions, and
           conduct in administration of the Plan herein embodied, and the
           Employers shall jointly and severally indemnify them, and each of
           them, from the effects and consequences of their acts, omissions,
           and conduct in their official capacity except to the extent that
           such effects and consequences shall result from their own willful
           misconduct.
      (i)  No member of the Committee shall receive any compensation or
           fee for his services, unless otherwise agreed between such member of
           the Committee and the Employers, but the Employers shall reimburse
           the Committee members for any necessary expenditures incurred in the
           discharge of their duties as Committee members.
      (j)  The Committee may employ such counsel (who may be of counsel
           for any Employer) and agents, and may arrange for such clerical and
           other services as it may require



                                     -88-



<PAGE>   94

           in carrying out the provisions of the Plan, and all fees, charges,
           and costs so incurred shall be payable by the Plan except to the
           extent the Employers elect to pay such fees, charges, and costs.
      (k)  The Committee shall maintain a record of all of its proceedings, 
           shall maintain or cause to be maintained the Plan Accounts 
           prescribed by Article VIII, and shall make the reports to
           Participants prescribed by section 8.7.

     10.2 Notice to Employees.  All notices, reports, and statements given,
made, delivered, or transmitted to a Participant shall be deemed to have been
duly given, made, or transmitted when mailed with postage prepaid and addressed
to the Participant at the address last appearing on the books of the Employer.
A Participant may record any change of his address from time to time by written
notice filed with the Employer.

     10.3 Notices to Employers or Committee.  Written directions, notices, and
other communications from Participants to the Employers or the Committee shall
be mailed by first class mail with postage prepaid or delivered to such
location as shall be specified upon the forms prescribed by the Committee for
the giving of such directions, notices, and other communications, and shall be
deemed to have been received by the addressee when received at such location.
Any other notice to the Employers or the Committee shall be addressed.

     (a) If intended for the Committee:

             Savings Plan Committee
             c/o Michigan Consolidated Gas Company
             500 Griswold Street
             Detroit, Michigan  48226

     (b) If intended for an Employer, at its principal place of business.



                                     -89-



<PAGE>   95
     10.4 Participants' Acceptance of the Provisions of the Plan.  Each
Participant at the time of becoming a Participant in the Plan and as a
condition of participation shall sign an instrument evidencing the fact that he
accepts and agrees to all provisions of the Plan.

     10.5 Audit of Plan Records.  The records of the Committee and the records
of the Employers in respect of the Plan shall be examined annually by a firm of
independent public accountants appointed by the Committee.  Such accountants
shall, on the basis of such examination, make such reports to the Committee and
to the Employers as they may request.  The audited records of the Committee and
the Employers shall be conclusive in respect of all matters involved in the
administration of the Plan.

     10.6 Claims Procedure.  If any Participant or distributee believes he is
entitled to benefits in an amount greater than those which he is receiving or
has received, he may file a claim with the Secretary of the Committee.  Such a
claim shall be in writing and state the nature of the claim, the facts
supporting the claim, the amount claimed, and the address of the claimant.

The Secretary of the Committee shall review the claim and give written notice
by registered or certified mail to the claimant of his decision with respect to
the claim.  Such notice shall be provided within 90 days after receipt of the
claim, unless special circumstances require an extension, in which event the
notice shall be provided within 180 days after receipt of the claim.  Such
notice shall be written in a manner calculated to be understood by the claimant
and, if the claim is wholly or partially denied, set forth the specific reasons
for the denial, specific references to the pertinent Plan provisions on which
the denial is based, a description of any additional material or information
necessary for the claimant to perfect the claim, and an explanation of why such
material or information is necessary, and an explanation of the claim review
procedure under the Plan.
        


                                     -90-



<PAGE>   96

The Secretary shall also advise the claimant that he or his duly authorized
representative may request a review by the full Committee of the denial by
filing with the Committee, within 60 days after notice of the denial has been
received by the claimant, a written request for such review.  The claimant
shall be informed that he may have reasonable access to pertinent documents and
submit comments in writing to the Committee within the same 60-day period.  If
a request is so filed, review of the denial shall be made by the full Committee
and the claimant shall be given written notice of the Committee's final
decision.  Such notice shall be provided within 60 days after receipt of such
request, unless special circumstances require an extension, in which event the
notice shall be provided within 120 days after receipt of the request.  Such
notice shall include specific reasons for the decision and specific references
to the pertinent Plan provisions on which the decision is based and shall be
written in a manner calculated to be understood by the claimant.
        
     10.7 Effect of a Mistake.  In the event of a mistake or misstatement as to
the eligibility, participation, or service of any Participant, or the amount of
payments made or to be made to a Participant or beneficiary, the Committee
shall, if possible, adjust the Plan's records and cause to be withheld or
accelerated or otherwise make adjustment of such amounts of payments as will in
its sole judgment result in the Participant or beneficiary receiving the proper
amount of payments under the Plan.



                                    -91-



<PAGE>   97
                     Article XI.  Amendment and Termination

     11.1 Amendment.  The Company may at any time and from time to time amend
or modify the Plan by written instrument duly adopted by the Board of Directors
of the Company.  Any such amendment or modification shall become effective on
such date as the Company shall determine, may apply to Participants in the Plan
at the time thereof as well as future Participants, but may not reduce the Plan
Account of any Participant as of the date of adoption of such amendment or
modification.

     11.2 Withdrawal.  If an Employer shall withdraw from the Plan under
section 12.2, or if an Employer shall adopt an amendment to the Plan which
shall render impracticable the continued administration of the Plan as a joint
plan of the several Employers, the Committee shall determine the portions of
the various funds held by the Trustee which are applicable to the Participants
of such Employer and shall direct the Trustee to segregate such portions in a
separate trust.  Such separate trust shall thereafter be held and administered
as a part of the separate plan of such Employer.  After such portions of the
funds have been segregated in a separate trust, no such Participant or any
distributee with respect to such Participant shall have any right to any
benefit under the Plan or any claim against the Trust.

     11.3 Termination.  Any Employer may at any time terminate its
participation in the Plan by resolution of its Board of Directors.  In the
event of any such termination, the Committee shall determine the portions of
the various funds held by the Trustee which are applicable to the Participants
of such Employer and shall direct the Trustee to distribute such portions to
such Participants ratably in proportion to the values of their respective fund
accounts; provided, however, amounts attributable to a Participant's Elective
Deferrals shall not be distributed on account of such termination if the
Employer, after such termination, maintains a defined contribution plan (other
than an
        
        

                                     -92-



<PAGE>   98


employee stock ownership plan or a simplified employee pension).  The portions
of the MCN Stock fund and the Primark Corporation Stock fund so distributed
shall be distributed in kind except that cash shall be distributed in lieu of
fractional shares.  The portions of the Fixed Income fund and other investment
funds so distributed shall be distributed in cash or in kind, or partly in cash
and partly in kind, as determined by the Committee.

Upon termination or partial termination of the Plan by any Employer or upon the
complete discontinuance of contributions by any Employer, the benefits under
the Plan of all affected Participants employed or formerly employed by such
Employer shall become nonforfeitable.

     11.4 Allocation of Funds Between Employers.  The portion of a fund
applicable to Participants of a particular Employer shall be an amount which
bears the same ratio to the value of the fund which the aggregate value of the
fund accounts of Participants employed by such Employer bears to the total
value of the fund accounts of all Participants.

     11.5 Trust to be Applied Exclusively for Participants and Their
Beneficiaries.  Subject to section 15.3, any provision of the Plan to the
contrary notwithstanding, it shall be impossible for any part of the Trust to
be used for or diverted to any purpose not for the exclusive benefit of
Participants and their beneficiaries either by operation or termination of the
Plan, by power of amendment, or by other means.

Notwithstanding the preceding paragraph, if a contribution is made to the Trust
by an Employer by a mistake of fact, then such contribution shall be returned
to such Employer within one year after the payment of the contribution; and if
any part or all of a contribution is disallowed as a deduction under Code
section 404, then to the extent such contribution is disallowed as a
        


                                     -93-



<PAGE>   99


deduction it shall be returned to such Employer within one year after the
disallowance.  All Employer contributions are conditioned upon their
deductibility under Code section 404.
        











        

                                    -94-



<PAGE>   100
              Article XII.  Participation by Affiliated Companies

      12.1 Adoption of the Plan.  Any Affiliated Company may become a
participating Employer under the Plan by (a) taking such corporate action as
shall be necessary to adopt the Plan, and (b) executing and delivering such
instruments and taking such other action as may be necessary or desirable to
put the Plan into effect with respect to such Affiliated Company.

The Plan shall become effective with respect to each particular Affiliated
Company which becomes a participating Employer after January 1, 1993, as of a
date to be determined by the Board of Directors of such Employer after
complying with all legal requirements pertaining to the participation of such
Employer in the Plan.

      12.2 Withdrawal from the Plan.  Any Employer may withdraw from
participation in the Plan at any time by filing with the Committee a duly
certified copy of a resolution of its Board of Directors to that effect and
giving notice of its intended withdrawal to the Committee, the other Employers,
and the Trustee at least 30 days prior to the effective date of withdrawal.

      12.3 Special Provisions Relating to Withdrawal by MCN Computer Services,
Inc.
      (a)  General.  The purpose of this section 12.3 is to set forth
           the terms and conditions that shall govern the withdrawal by MCN
           Computer Services, Inc. ("CSI") from participation in the Plan.  In
           the event of any conflict between any other provision of the Plan
           and this section 12.3, the terms of this section 12.3 shall govern
           with respect to such withdrawal.  This section 12.3 shall be
           effective as of June 18, 1992 (the date on which the Internal
           Revenue Service issued a favorable determination letter with 
           respect to the provisions contained in this section 12.3 (then 
           Article 21).



                                     -95-



<PAGE>   101

      (b)   Provisions with Respect to Withdrawal by CSI.  Upon CSI's
            withdrawal of its participation in the Plan as a participating
            Employer--
            (1)  the value of the Plan Account of each Participant
                 who is actively employed by CSI on the date of CSI's
                 withdrawal of participation in the Plan shall be transferred
                 to the Genix Group Retirement Savings Plan (formerly known as
                 the Retirement Savings Plan for Salaried Employees of Genix
                 Corporation) (the "Genix Plan") and such Participant shall no
                 longer have any rights of any nature under this Plan;
            (2)  the value of such Participant's Plan Account, determined as 
                 of the Valuation Date coincident with or immediately preceding 
                 the transfer, shall be transferred to the Genix Plan as 
                 follows:
                 (A)  the value of the Participant's MCN
                      Stock fund account(s), if any, determined in accordance
                      with section 9.8, shall be transferred in full shares of
                      stock, except that cash shall be transferred in lieu of
                      fractional shares; and
                 (B)  the value of the Participant's other fund accounts shall
                      be transferred in cash;
            (3)  Such amounts shall be transferred to the Genix Plan as soon 
                 as practicable following the filing of any applicable forms 
                 required by the Internal Revenue Service and the expiration 
                 of any waiting period in connection therewith; and
            (4)  the amount so transferred shall be subject to the terms and 
                 provisions of the Genix Plan; provided, however, that the 
                 amount so transferred, as adjusted for earnings or loss 
                 thereon, shall be fully vested at all times.
            Any Participant that has retired according to the provisions of the
            Plan on the date of CSI's withdrawal



                                     -96-



<PAGE>   102
           shall continue to participate in the Plan and to receive benefits
           in accordance with the terms and conditions of the Plan.
      (c)  No Further Service or Contributions.  Notwithstanding any
           other provision of this Plan, employees of CSI shall not receive
           credit under this Plan for any service on or after January 1, 1992,
           and shall receive no further contributions under this Plan on or
           after such date.

     12.4  Company as Agent for Employers.  Each Employer named under section
2.1(x), other than the Company, hereby appoints, and each other corporation
which shall become an Employer pursuant to section 12.1 or 15.7 by so doing
shall be deemed to have appointed the Company its agent to exercise on its
behalf all of the powers and authorities hereby conferred upon the Employers by
the terms of the Plan, including, but not by way of limitation, the power to
amend, restate, and terminate the Plan.  The authority of the Company to act as
agent shall continue unless and until the portion of the Trust fund held for
the benefit of Employees of the particular Employer and their beneficiaries is
set aside in a separate trust as provided in section 11.2.



                                     -97-



<PAGE>   103

                      Article XIII.  Top-Heavy Plan Rules

     13.1  Application of Top-Heavy Plan Rules.  If the Plan is top-heavy as
determined under section 13.3, then the requirements in section 13.4 shall
apply to the Plan to the extent indicated by that section 13.4.

     13.2  Special Definitions.  Any reference in this Article XIII to a "plan"
means a stock bonus, pension, or profit-sharing plan of the Company and any
Affiliated Company for the exclusive benefit of its employees or their
beneficiaries, including this Plan.  For purposes of this Article XIII only,
the following terms shall have the meanings indicated:
      (a)  "Compensation" means a Participant's Compensation from the
           Employer for any calendar year as defined in section 2.1(l) except
           amounts not currently includible in gross income by reason of the
           application of Code section 125 or 402(e)(3) (402(a)(8) prior to
           1993) shall be excluded.
      (b)  "Determination Date" means, with respect to any Plan Year,
           the last day of the preceding Plan Year, except that in the case of
           the Plan's first Plan Year, the Determination Date shall be the last
           day of that Plan Year.  Where one or more other plans are required
           or permitted to be aggregated with this Plan under section 13.3 and
           where all plan years of all such plans do not coincide, the "Key
           Employee Sum" and the "All Employee Sum" in section 13.3 each shall
           be determined separately for each plan as of its appropriate
           Determination Date and the results shall then be combined for the
           Determination Dates falling within the same calendar year.
      (c)  "Employee" means a common law employee of the Employer who is
           or once was a Participant, including his beneficiary, but excluding
           any employee who is a member of a unit of employees covered by a 
           collective bargaining agreement under which retirement benefits



                                     -98-



<PAGE>   104

           were the subject of good faith bargaining with the Employer unless
           a member of such unit is a Key Employee.  For purposes of making
           computations involving the MichCon Employee Stock Ownership Plan,
           employee shall include any common law employee of the Employer,
           including his beneficiary.
      (d)  "Employer" means the Company and any other employing unit
           which would be included in the same controlled group as the Company
           (as defined in Code section 414(b)) or which is under common control
           with the Company (as defined in Code section 414(c)) or which is
           included in the same affiliated service group (as defined in Code
           section 414(m)) or which is required to be aggregated with the
           Company pursuant to Regulations under Code section 414(o).
      (e)  "Key Employee" means each Employee or former Employee
           (including the beneficiary of either) who at any time during the
           Plan Year containing the Determination Date or any of the four
           preceding Plan Years received Compensation from the Employer and
           who--
           (1)   is one of the 50 (or, if fewer, the greater of 3 or 10 
                 percent of all Employees) officers of the Employer who
                 had the largest Compensation in the five-year period ending on
                 the last day of the current Plan Year but only if such
                 officer's Compensation exceeds 0.5 times the dollar limitation
                 of Code section 415(b) for the calendar year in which the
                 Determination Date falls;
            (2)  is one of the ten Employees owning the largest interest in 
                 the Employer and who has Compensation from the Employer in 
                 the amount greater than the dollar limitation of Code section
                 415(c) in effect for the calendar year in which the 
                 Determination Date falls;
            (3)  owns 5 percent or more of the outstanding stock or voting 
                 power of the Employer; or



                                     -99-



<PAGE>   105
            (4)  owns 1 percent or more of the outstanding stock or voting 
                 power of all stock of the Employer and has annual compensation 
                 from the Employer of more than $150,000.
            For purposes of (2), (3), and (4), the constructive ownership rules
            of Code section 318 shall apply with the modification that 5
            percent shall be substituted for 50 percent appearing in Code
            section 318(a)(2)(C).  For purposes of (2), an Employee shall be
            considered a Key Employee even if he is not among the ten largest
            owners, if his ownership interest in the Employer is not less than
            at least one of the top ten owners, and provided he has the
            requisite level of Compensation described in (2); and in the event
            two Employees have the same interest in the Employer, the Employee
            with the greater Compensation shall be regarded as having the
            larger interest.  For purposes of (2), (3), and (4), each Employer
            that otherwise would be aggregated under this Article XIII's
            definition of Employer shall be treated as a separate Employer to
            determine ownership percentages.
      (f)   "Non-Key Employee" means any Employee or former Employee
            (including the beneficiary of either) who is not a Key Employee.
      (g)   "Plan Year" means the calendar year.
      (h)   "Valuation Date" means the date used for computing plan costs
            for minimum funding in the case of any defined benefit plan and the
            last day of the plan year in the case of any defined contribution
            plan, including this Plan.
      (i)   "Years of Service" means an Employee's Years of Service
            determined under section 3.5.

     13.3   Determination of Top-Heavy Status.  Determination of whether the 
Plan is top-heavy for any Plan Year shall be made as follows:



                                     -100-



<PAGE>   106


      (a)  Required Plan Aggregation.  First, there shall be aggregated
           with the Plan (1) each plan of the Employer in which a Key Employee
           participates in the plan year containing the Determination Date, or
           any of the four preceding plan years, (2) each other plan of the
           Employer which, during this period, enables any plan in which a Key
           Employee participates to meet the requirements of Code section
           401(a)(4) or 410, and (3) any terminated plan that was maintained by
           the Employer during the five year period ending on the Determination
           Date for the plan year in question if a Key Employee participated in
           such plan.
      (b)  Key Employee Sum.  Second, there shall be computed, as of the
           Determination Date, the sum of the present values of the accrued
           benefits of all Key Employees as determined by the Plan actuary
           under all defined benefit plans required to be aggregated under
           section 13.3(a) and the account balances of all Key Employees under
           all defined contribution plans, including this Plan, required to be
           aggregated under section 13.3(a).  For purposes of this computation,
           the present value of an accrued benefit shall be determined as of
           the most recent Valuation Date occurring within a 12-month period
           ending on the Determination Date with the accrued benefit for a
           current Participant determined as if the individual had terminated
           employment as of such Valuation Date.

           For purposes of this computation, the accrued benefit of an
           Employee other than a Key Employee shall be determined under (1)
           the method, if any, that uniformly applies for accrual purposes
           under all plans maintained by the Company and Affiliated Companies,
           or (2) if there is no such method, as if such benefit accrued not
           more rapidly than the slowest accrual rate permitted under the
           fractional accrual rate of Code section 411(b)(1)(C).



                                     -101-



<PAGE>   107

            For purposes of this computation, account balance means the account
            balance as of the most recent Valuation Date occurring within a
            12-month period ending on the Determination Date, plus an
            adjustment for contributions due as of the Determination Date.  In
            the case of a profit-sharing plan or other plan not subject to the
            minimum funding requirements of Code section 412, the adjustment is
            the amount of any contributions actually made after the Valuation
            Date but on or before the Determination Date, except that in the
            first plan year after a plan is adopted, the adjustment shall
            include any contributions made after the Determination Date that
            are allocated as of a date within the first plan year.  In the case
            of a money purchase pension plan or other plan subject to the
            minimum funding requirements of Code section 412, the adjustment is
            the amount of any contributions that would be allocated as of a
            date not later than the Determination Date, even though such amount
            is not yet required to be contributed, plus the amount of any
            contribution actually made (or due to be made) after the Valuation
            Date but prior to the expiration of the extended payment period
            under Code section 412(c)(10).

            For purposes of this computation--
            (A)  there shall be included in the Key Employee Sum
                 any distribution (other than rollover amounts or plan-to-plan
                 transfers not initiated by the Employee or made to another
                 plan maintained by the Employer) made to an Employee from the
                 Plan, or from another plan required to be aggregated under
                 section 13.3(a), within the five-year period ending on the
                 Determination Date;
            (B)  there shall be excluded from the Sum any rollover contribution 
                 and any plan-to-plan transfer



                                     -102-



<PAGE>   108

                 initiated by the Employee and accepted after December 31,
                 1983, by any plan required to be aggregated under section
                 13.3(a) from a plan other than one maintained by the
                 Employer;
            (C)  there shall be excluded from the Sum the account balance and 
                 present value of the accrued benefit of any Employee who 
                 formerly was a Key Employee but who is not a Key Employee for
                 the year ending on the Determination Date; and
            (D)  there shall be excluded from the Sum any amounts attributable
                 to tax deductible employee contributions.
      (c)  All Employee Sum.  Third, under the same procedures as set forth 
           in section 13.3(b) above, including the special rules in (A),
           (B), and (C), there shall be computed the sum of present values of
           accrued benefits and account balances for all Employees of the
           Employer.
      (d)  Top-Heavy Test Fraction.  Fourth, the Key Employee Sum computed 
           in section 13.3(b) shall be divided by the All Employee Sum
           computed in section 13.3(c), and if the resulting fraction is 0.60
           or less, neither this Plan nor any plan required to be aggregated
           under section 13.3(a) is top-heavy for the Plan Year.  If the
           fraction is greater than 0.60, both this Plan and any plan required
           to be aggregated under section 13.3(a) are top-heavy for the Plan
           Year, unless after the permissive plan aggregation described in
           section 13.3(e) below, the recomputed fraction is 0.60 or less.
      (e)  Permissive Plan Aggregation.  Fifth, at the election of the
           Employer, plans of the Employer, other than those required to be
           aggregated under section 13.3(a), but which provide benefits or
           contributions comparable to this Plan, may be aggregated with this
           Plan and the plans required to be aggregated under section 13.3(a),
           provided that such aggregated group would meet the requirements of
           Code section 401(a)(4) and 410.  The computations under section
           13.3 (b) to (d) above may



                                     -103-



<PAGE>   109

            then be repeated, based on this permissively aggregated group, and
            if the fraction computed in section 13.3(d) is 0.60 or less for
            this group, then neither this Plan nor any plan required to be
            aggregated under section 13.3(a) is top-heavy for the Plan Year.
            If the fraction computed in section 13.3(d) is still greater than
            0.60, both this Plan and any plan required to be aggregated under
            section 13.3(a) are top-heavy for the Plan Year but no plan which
            is permissively aggregated under this section 13.3(e) will be
            deemed to be top-heavy for such reason.

     13.4   Superseding Rules.
      (a)   Provisions Mandatory.  For each Plan Year that the Plan is
            top-heavy, the provisions of paragraphs (b), (c), (d), and (e) of
            this section 13.4 are mandatory and shall apply to the Plan for that
            Plan Year, notwithstanding any other provision or provisions of the
            Plan that may conflict with or vary from said mandatory provisions.
      (b)   Compensation Limit.  For Plan Years beginning before January
            1, 1989, Compensation of any Employee from the Employer shall be
            disregarded for all purposes under the Plan to the extent such
            Compensation exceeds $200,000 (or such higher cost-of-living
            adjusted amount as determined from time to time by the Secretary of
            Treasury).
      (c)   Minimum Contributions for Non-Key Employee Participants.
            Contributions by the Employer to the Plan Account of each Non-Key
            Employee Participant who is employed by the Employer on the last day
            of the Plan Year and who is eligible to have an Employer 
            contribution made to his Plan Account under section 4.2, 4.3, or 4.4
            (without regard to any requirement of a minimum number of Hours of
            Employment (as defined in section 3.7) during the Plan Year) shall
            be equal to the lesser of (1) 3 percent of the Participant's



                                     -104-



<PAGE>   110
            Compensation for that Plan Year or (2) the maximum percentage of
            the Employer's contributions (as a percentage of Compensation not
            in excess of $200,000) allocated to the account of any Participant
            who is a Key Employee for the Plan Year multiplied by the Non-Key
            Employee Participant's Compensation for that Plan Year.  For
            purposes of this section 13.4(c), Employer contributions made under
            any other defined contribution plan of the Employer in which any
            Key Employee participates or which enables another defined
            contribution plan of the Employer to meet the requirements of
            either Code section 401(a)(4) or 410 shall be considered
            contributions made under this Plan.

            Notwithstanding the foregoing, in the event that the contribution
            to be made to the Plan Account on behalf of the Non-Key Employee
            under the provisions of sections 4.2, 4.3, and 4.4 is greater than
            the contribution which would be made under this section 13.4(c),
            the provisions of Article IV shall prevail.
      (d)   Accelerated Vesting.  A Participant's vested percentage in the 
            portion of his account balance derived from Employer contributions 
            described sections 4.2, 4.3, and 4.4 shall be determined in 
            accordance with the following schedule but only with respect to 
            those who are Participants during part or all of the Plan Year 
            after the Plan becomes top-heavy and only if the following
            schedule results in a higher vested percentage than the application
            of the Plan's normal Vesting Requirement:


<TABLE>
<CAPTION>
                      Years of Vested Service  Percentage
                      -----------------------  ----------
<S>                                            <C>
                                0                   0%
                                2                  20%
                                3                  40%
                                4                  60%
                                5                  80%
                                6                 100%
</TABLE>



                                     -105-



<PAGE>   111

      (e)  Reduction in Multiple Plan Limitations.  In order to reduce
           the overall limitations on combined plan contributions and benefits
           under Code section 415, the number 1.0 shall be substituted for 1.25
           in determinations of the maximum dollar amount which can be added to
           a Participant's account and of the dollar amount of the maximum
           benefit allowable in section 4.3 of the Plan; provided, however,
           that the foregoing sentence shall not apply if the top-heavy test
           fraction or recomputed fraction of section 13.3(e) is .90 or less,
           in which event each Non-Key Employee Participant shall receive an
           additional minimum contribution to his account equal to 1 percent of
           the Participant's Compensation for that Plan Year.

     13.5  Participants in More Than One Top-Heavy Plan of
the Employer.  For each Plan Year that the Plan is top-heavy--
      (a)  Subject to the provisions of section 13.4(c), in the event
           that a Non-Key Employee is a Participant in both this Plan and
           another defined contribution plan of the Employer in the same Plan
           Year, such Employee shall in all events be entitled to have the
           portion of the contribution by the Employer specified in section
           4.2, 4.3, or 4.4 or the contribution by the Employer specified in
           section 13.4(c), whichever is appropriate, allocated to his account.
           This provision shall in no way limit the Employee's right to have a
           contribution made on his behalf to such other defined contribution
           plan as shall be maintained by the Employer and in which he is a
           participant.
      (b)  In the event that a Non-Key Employee is a Participant in both
           this Plan and a defined benefit plan of the Employer in the same
           Plan Year, such Employee shall not be entitled to have the
           contribution specified in section 13.4(c) made by the Employer to 
           this Plan on his behalf.  This provision shall in no way limit the 
           Employee's right to have the portion of the



                                     -106-



<PAGE>   112

            contribution by the Employer specified in section 4.2, 4.3, or 4.4
            allocated to his account.  Such Employee shall, however, receive
            the defined benefit minimum as specified in Treasury Regulation
            section 1.416-1, M-12, and such minimum shall be increased, if the
            Company uses a factor of 1.25 in computing the denominators of the
            defined benefit and defined contribution factors under Code section
            415(e), by one percentage point (up to a maximum of ten percentage
            points) for each Year of Service described in Treasury Regulation
            1.416-1, M-2 (disregarding, as permitted therein, any Year of
            Service if the Plan was not top-heavy for any Plan Year ending
            during such Year of Service, or if the Year of Service was
            completed in a Plan Year beginning before January 1, 1984) of the
            Participant's average Compensation for the Plan Years described in
            Treasury Regulation section 1.416-1, M-2 (disregarding, as
            permitted therein, Compensation received for years ending in Plan
            Years beginning before January 1, 1984 and Compensation received
            for years beginning after the close of the last Plan Year in which
            the Plan is top-heavy).  Treasury Regulation sections 1.416-1,
            M-14, M-12, and M-2 shall govern how the multiple plan requirements
            are satisfied.

     13.6 Changes in Applicable Vesting Schedule.  In the case of any change in
the vesting provisions of the Plan, whether or not due to a change in the
Plan's status as a top-heavy plan determined pursuant to section 13.3, each
Participant whose nonforfeitable benefits are adversely affected by the change
may elect during the election period to have his nonforfeitable benefits
determined without regard to such change.  The election period shall begin on
the date the change is adopted or becomes effective, whichever is earlier, and
end on the latest of (a) the 

                                    -107-


<PAGE>   113
date which is 60 days after the change is adopted, (b) the date which is 60
days after the date such change becomes effective, or (c) the date which is 60
days after the day the Participant is given written notice of such change.












                                    -108-
        
<PAGE>   114

             Article XIV.  Special Provisions Relating to the ESOP

     14.1 Establishment of ESOP.  The MichCon Employee Stock Ownership Plan for
Non-Union Employees was originally established effective as of April 1, 1989.
Each Employer shall make contributions to the ESOP in accordance with section
4.3 hereof and the assets of the ESOP shall be invested at all times primarily
in MCN Stock.  The Company from time to time may direct the Trustee to incur
debt in accordance with section 14.4 hereof to finance the acquisition of MCN
Stock.

     14.2 ESOP Account.  The Committee shall establish an ESOP Account in the
name of each Participant to which there shall be credited or charged--
      (a)  the Employer contributions under section 4.3(a) and (c) hereof made
           on behalf of such Participant;
      (b)  the shares allocated to the Participant pursuant to section 14.4(d)
           hereof; and
      (c)  the investment gains and losses on such amounts.
A Participant's ESOP Account shall be invested only in the MCN Stock fund,
except to the extent that monies diversified under section 14.5 may, at the
Participant's election, be directed to the Equities fund, the Senior Securities
fund, or the Fixed Income fund.

     14.3 Discrimination Testing.  For purposes of the limitations on Salary
Reduction allotments set forth in section 4.8 and the limitations on Voluntary
Deduction allotments and Employer contributions set forth in section 4.13, the
ESOP and non-ESOP portions of the Plan shall be tested separately.  For
purposes of such testing--
      (a)  the ESOP portion of the Plan shall mean Employer contributions under 
           section 4.3(a) made on behalf of the Participant and the shares 
           allocated to a Participant's ESOP Account pursuant to section 
           14.4(d); and



                                     -109-



<PAGE>   115

      (b)  the non-ESOP portion of the Plan shall mean all Elective Deferrals,
           Voluntary Deductions and Employer contributions under section 4.2.

     14.4  Loans.
      (a)  Stock Acquired with Exempt Loan.  The Company may direct the
           Trustee to incur a loan on behalf of the ESOP in a manner and under
           conditions which will cause the loan to qualify as an "exempt loan"
           within the meaning of Code section 4975(d)(3).  A loan shall be used
           primarily for the benefit of Participants and their beneficiaries.
           The proceeds of each such loan shall be used, within a reasonable
           time after the loan is obtained, only to purchase MCN Stock, to
           repay the loan, or to repay any prior loan.

           Any such loan shall provide for a reasonable rate of interest and
           an ascertainable period of maturity, and shall be without recourse
           against the Plan.  Any such loan shall be secured solely by shares
           of MCN Stock acquired with the proceeds of the loan and shares of
           MCN Stock that were used as collateral on a prior loan which was
           repaid with the proceeds of the current loan.

           MCN Stock acquired with the proceeds of a loan, including shares
           pledged as collateral, shall be placed in a Suspense Account and
           released in accordance with subsection (b) below as the loan is
           repaid as if all shares in the Suspense Account were pledged.  MCN
           Stock released from the Suspense Account shall be allocated in the
           manner described in subsection (d) below.

           No person entitled to payment under a loan made pursuant to this
           section 14.4 shall have recourse against any assets of the Plan 
           other than the MCN Stock used as collateral for the loan, Employer 
           contributions



                                     -110-



<PAGE>   116

           under section 4.3 that are available to meet obligations under the
           loan, and earnings attributable to such collateral and the
           investment of such contributions.  Employer contributions under
           section 4.3(b) made with respect to any Plan Year during which the
           loan remains unpaid, and earnings on such contributions, shall be
           deemed available to meet obligations under the loan, unless
           otherwise provided by the Employer at the time such contributions
           are made.
      (b)  Release of Pledged Shares.  Any pledge of MCN Stock as collateral 
           under this section 14.4 shall provide for the release of shares 
           so pledged upon the payment of any portion of the principal
           of the loan.  Shares so pledged shall be released in the proportion
           that the principal paid on the loan bears to the total principal
           amount of the loan, as provided in Treasury Regulation
           54.4975-7(b)(8)(ii).  The number of shares of MCN Stock that shall
           be released with each principal payment on the loan shall be equal
           to the number of shares of MCN Stock held as collateral on the loan
           immediately prior to the release multiplied by a fraction the
           numerator of which is the amount of principal of the loan repaid on
           such date and the denominator of which is the sum of the numerator
           plus the remaining outstanding principal amount of the loan after
           giving effect to the repayment of principal of the loan on such
           date.  Each loan under this section 14.4 shall comply with the
           requirements of Treasury Regulation 54.4975-7(b)(8)(ii).  If such a
           loan provides for monthly principal payments, shares of MCN Stock
           shall be released monthly.
      (c)  Repayment of Loan.  Payments of principal and interest on any loan 
           under this section 14.4 shall be made by the Trustee at the 
           direction of the Company solely from--



                                     -111-



<PAGE>   117

            (1)  the proceeds of such loan, if any portion of such proceeds 
                 are used for such purpose within a reasonable period
                 of time after the loan is obtained as provided in section
                 14.4(a) above;
            (2)  Employer contributions under section 4.3(b) available to meet
                 obligations under the loan;
            (3)  earnings from the investment of such contributions;
            (4)  earnings attributable to MCN Stock acquired with the proceeds
                 of such loan, whether allocated or unallocated;
            (5)  the earnings on other allocated shares of MCN Stock held by 
                 the ESOP if the Internal Revenue Service, by private letter 
                 ruling, advises the Company that the use of such earnings to 
                 repay the loan will be deductible under Code section 
                 404(k)(2)(C) and will not violate the requirements of
                 Code section 4975; and
            (6)  the proceeds of a subsequent loan made to repay the loan.

            The contributions and earnings available to pay a loan must be
            accounted for separately by the Committee until all loans under
            this section 14.4 have been paid.  If dividends on MCN Stock
            allocated to the ESOP Account of any Participant are used to repay
            any loan, shares of MCN Stock with a fair market value not less
            than the amount of such dividends shall be allocated in accordance
            with section 4.3(c) to the ESOP Account of such Participant prior
            to the end of the Plan Year during which (but for the use of the
            dividends to repay the loan) such dividend would have been
            allocated to the ESOP Account of such Participant.
      (d)   Allocation of Released Shares.  Subject to the limitations in
            section 4.13 on Annual Additions to a Participant's accounts, 
            shares of MCN Stock released from a Suspense Account described in 
            section 14.4(a) shall be allocated immediately to the ESOP 
            Accounts of



                                     -112-



<PAGE>   118
            each Participant in the proportion that the contribution that would
            be required to be made on behalf of such Participant under section
            4.3(a)(1) for the applicable period if no shares were allocated
            under section 4.3(a)(2) during such period bears to the total of
            all Employer contributions that would be required under section
            4.3(a)(1) hereof for the applicable period if no shares were
            allocated under section 4.3(a)(2) during such period.

     14.5 Diversification.  Any Participant or any former Participant whose
distribution has been deferred pursuant to section 9.7(a), who, in either case,
has completed at least ten years of participation in the Plan, and who has
attained the age of 55 is a "Qualified Participant".  Any Qualified Participant
shall have the right to make an election to direct the investment of a portion
of his ESOP Account.  Such a Participant may elect within 90 days after the
close of each Plan Year in the six plan-year period beginning with the first
Plan Year in which the individual becomes a Qualified Participant to diversify
25 percent of his ESOP Account, less any amount to which a prior election
applies.  In the case of the last year to which an election applies, 50 percent
shall be substituted for 25 percent.

The portion of a Qualified Participant's ESOP Account which is eligible for
diversification may be invested in the Fixed Income fund and/or any other
investment funds under the Plan, in any combination thereof.

     14.6 Put Option.  If MCN Stock becomes not readily tradable on an
established market, then any Participant who is otherwise entitled to a
distribution of his ESOP Account, shall have the right (hereinafter referred to
as "Put Option") to require that his Employer repurchase any MCN Stock
allocated to his ESOP Account under a fair valuation formula.  The Put Option
shall be exercisable only by written notice to the Participant's Employer
during the 60-day period immediately following the date of
        


                                     -113-



<PAGE>   119

distribution and if the Put Option is not exercised within such 60-day period,
then it can be exercised for an additional period of 60 days in the following
Plan Year.  The period during which the Put Option is exercisable shall not
include any time when a Participant is unable to exercise it because his
Employer is prohibited from honoring it by applicable federal or state law.
This Put Option shall be nonterminable within the meaning of Treasury
Regulation 54.4975-(11)(a)(ii).

The amount paid for MCN Stock under the Put Option shall be paid in
substantially equal periodic payments (not less frequently than annually) over
a period beginning not later than 30 days after the exercise of the Put Option
and not exceeding five years.  There shall be adequate security provided and
reasonable interest paid on the unpaid balance due under this section 14.6.

     14.7 Purchase of MCN Stock.  The ESOP may acquire shares of MCN Stock on a
national securities exchange, from the Company or any Affiliated Company or
otherwise; provided, however, that if any shares of MCN Stock are purchased
from the Company or any Affiliated Company, the price shall not exceed an
amount which constitutes adequate consideration (as defined in ERISA section
3(18) and any Regulations thereunder) and such purchase shall satisfy all other
requirements of ERISA and the Code applicable to such purchases.  Except as
provided in section 14.6 or as otherwise required by applicable law, no shares
of MCN Stock acquired by the ESOP shall be subject to a put, call, or other
option, or buy-sell or similar arrangement while held by and when distributed
from the Plan, whether or not any part of the Plan is then an ESOP.  The
protection afforded to Participants in the preceding sentence is nonterminable
within the meaning of Treasury Regulation section 54.4975-(1)(a)(ii).


                                    -114-



<PAGE>   120
                           Article XV.  Miscellaneous

     15.1 Beneficiary Designation.  Subject to the provisions of section 9.9
and this section 15.1, each Participant shall have the right to designate a
beneficiary or beneficiaries to receive any distribution to be made under
section 9.1 upon the death of such Participant, or, in the case of a
Participant who dies subsequent to termination of his employment but prior to
the distribution of the entire amount to which he is entitled under the Plan,
any undistributed balance to which such Participant would have been entitled.

In the event of the death of a Participant whose spouse survives him, the
beneficiary of the Participant shall be his surviving spouse unless such spouse
has consented in writing to the designation of another beneficiary or
beneficiaries.  Any such written consent shall acknowledge the effect of such
election and shall be witnessed by a notary public or by a representative of
the Committee who is designated to act in such capacity by the Committee.  In
the event a Participant dies without a surviving spouse, or, in the event the
surviving spouse of a Participant has executed the written consent hereinabove
described, any distributions to be made under section 9.1 upon the death of the
Participant shall be made to his designated beneficiary or beneficiaries.  If
the Participant establishes to the satisfaction of the Committee or its
designated representative that such written consent cannot be obtained because
his spouse cannot be located, the requirement of such written consent shall be
waived.

If no beneficiary has been named by a Participant who dies without a surviving
spouse or if the beneficiary designated by such a Participant or by a
Participant whose surviving spouse has executed the written consent hereinabove
described has predeceased the Participant or such designated beneficiary has
        
        

                                     -115-



<PAGE>   121

died prior to complete disbursement of the Participant's Plan Account, the
value of his account, or the undistributed portion thereof, shall be paid by
the Trustee at the direction of the Committee--
      (a)  to the surviving spouse of such deceased Participant, if any;
      (b)  if there shall be no surviving spouse, to the surviving
           children of such deceased Participant, if any, in equal shares;
      (c)  if there shall be no surviving spouse or surviving children,
           to the executors or administrators of the estate of such deceased
           Participant; or
      (d)  if no executor or administrator shall have been appointed for
           the estate of such deceased Participant, to the person or persons
           who would be entitled to the personal estate of such deceased
           Participant under the laws of his state of domicile if he had died
           leaving no will.
In the event that a Participant and his spouse die under circumstances such
that it is not clear whether the spouse survived the Participant, the
Participant shall be presumed to have survived the spouse.

     15.2 Incompetency.  Any distribution under this Plan which is payable to a
beneficiary who is a minor or to a Participant or beneficiary who, in the
opinion of the Committee, is unable to manage his affairs by reason of illness
or mental incompetency, may be made to or for the benefit of any such
Participant or beneficiary in such of the following ways as the Committee shall
direct:
      (a)  Directly to any such minor beneficiary, if, in the opinion of
           the Committee, he is able to manage his affairs;
      (b)  To the legal representative of any such Participant or beneficiary;
           or
      (c)  To some near relative of any such Participant or beneficiary to be 
           used for the latter's benefit.



                                    -116-



<PAGE>   122
     15.3 Expenses.  Except as otherwise provided in the Plan, all costs and
expenses incurred in administering the Plan, including the expenses of the
Committee, the fees and expenses of the Trustee, the fees of its counsel, and
other administrative expenses, shall be borne by the Plan except to the extent
the several Employers elect to bear such costs, fees, and expenses in such
proportions as the Committee shall determine to be equitable and proper having
regard to the nature of the particular expense.

     15.4 Nonassignability.  Except as may be required to comply with a
qualified domestic relations order (as defined in Code section 414(p)), it is a
condition of the Plan, and all rights of each Participant shall be subject
thereto, that no right or interest of any Participant in the Plan or in a Plan
Account shall be assignable or transferable in whole or in part, either
directly or by operation of law or otherwise, including, but not by way of
limitation, execution, levy, garnishment, attachment, pledge, or bankruptcy but
excluding devolution by death or mental incompetency, and no right or interest
of any Participant in the Plan or in his Plan Account shall be liable for, or
subject to, any obligation or liability of such Participant.

     15.5 Employment Noncontractual.  The Plan confers no right upon any
Employee to continue in employment.

     15.6 Merger or Consolidation with Another Plan.  A merger or consolidation
with, or transfer of assets or liabilities to, any other plan shall not be
effected unless the terms of such merger, consolidation, or transfer are such
that each Participant, distributee, beneficiary, or other person entitled to
receive benefits from the Plan would, if the Plan then terminated, receive a
benefit immediately after the merger, consolidation, or transfer which is equal
to or greater than the benefit such person would have been entitled to receive
immediately before the merger, consolidation, or transfer if the Plan had then
terminated.
        


                                     -117-



<PAGE>   123

If any other plan shall be merged into and become a part of this Plan, each
Participant or the person entitled to receive a benefit under such other plan
shall be entitled to receive a benefit under this Plan which is equal to the
benefit such person would have been entitled to receive had such other plan
terminated immediately before the merger.

     15.7 Continuance by a Successor.  In the event that any Employer
corporation shall be reorganized by way of merger, consolidation, transfer of
assets, or otherwise, so that another Affiliated Company shall succeed to all
or a portion of such Employer's business, such successor corporation, with the
consent of each other participating Employer, may be substituted for such
Employer under the Plan by adopting the Plan and becoming a party to the Trust
Agreement.  Employee allotments and Employer contributions shall be
automatically suspended from the effective date of any such reorganization
until the date upon which the substitution of such successor corporation for
the Employer under the Plan becomes effective.  If, within 90 days from the
effective date of any such reorganization, such successor corporation shall not
have become a party to the Plan, or, if the Employer shall adopt a plan of
complete liquidation other than in connection with a reorganization, the Plan
shall be automatically terminated with respect to Employees of such Employer as
of the close of business on the ninetieth day following the effective date of
such reorganization or as of the close of business on the date of adoption of
such plan of complete liquidation, as the case may be, and the Trustee shall
distribute the portion of the Trust applicable to Participants of such Employer
in the manner provided in section 11.3.



                                     -118-



<PAGE>   124

     15.8  Elimination of Certain Provisions.  Effective January 1, 1993--

      (a)  all references to Primark Corporation Stock and the Primark
           Corporation Stock fund shall be deleted from the Plan; and
      (b)  all provisions that ceased to apply on any date prior to January 1,
           1993 shall be deleted from the Plan.

                              * * * * * * * * * *













                                     -119-

<PAGE>   125

     IN WITNESS WHEREOF, Michigan Consolidated Gas Company has caused its
corporate name to be hereunto affixed by its duly authorized officers as of the
29th day of December, 1993.

                                     MICHIGAN CONSOLIDATED GAS COMPANY


ATTEST:
                                     By /s/ Carol McCallion                   
                                        ---------------------

By /s/ Douglas A. Green             
   --------------------
     (Corporate Seal)





                                     -120-


<PAGE>   126

                             FIRST AMENDMENT TO THE
                     1989 AMENDMENT AND RESTATEMENT OF THE
                    MICHCON SAVINGS AND STOCK OWNERSHIP PLAN


     WHEREAS, Michigan Consolidated Gas Company (the "Company") has previously
established the MichCon Savings and Stock Ownership Plan (the "Plan"), which was
most recently amended and restated effective January 1, 1989;

     WHEREAS, FURTHER, pursuant to Section 11.1 of the Plan, the Company has
reserved the right to amend the Plan from time to time;

     WHEREAS, FURTHER, in connection with the process by which the Company is
seeking a favorable determination letter from the Internal Revenue Service
regarding the 1989 Amendment and Restatement of the Plan, the Internal Revenue
Service has requested that certain provisions of the Plan be amended, effective
January 1, 1989.

     NOW, THEREFORE, the Plan is hereby amended as follows, effective January 1,
1989:

     1.   THE FOLLOWING SHALL BE ADDED AT THE END OF SECTION 2.1(l):

               If as a result of the application of such rules, the adjusted
          $200,000/$150,000 limitation is exceeded, then the limitation shall be
          prorated among the affected individuals in proportion to each such
          individual's compensation as determined under this Section prior to
          the application of the limitation.

     2.   SECTION 2.1(r) SHALL BE AMENDED BY THE ADDITION OF THE FOLLOWING AT
THE END THERETO:

               If as a result of the application of such rules, the adjusted
          $200,000/$150,000 limitation is exceeded, then the limitation shall be
          prorated among the affected individuals in proportion to each such
          individual's compensation as determined under this Section prior to
          the application of the limitation.

     3.   SECTION 3.2 SHALL BE AMENDED IN ITS ENTIRETY AS FOLLOWS:

               Section 3.2  Eligibility Upon Merger or Reemployment.  Any
          Employee who is a Participant in any plan which is merged into this
          Plan shall become a Participant in this Plan immediately upon the
          effective date of the merger.  Such an Employee shall be eligible to
          actively participate in this Plan in accordance with Section 3.4.


<PAGE>   127

               If a Participant's employment is terminated and he is thereafter
          reemployed before incurring a Break in Service Year, he shall be
          eligible again to actively participate in the Plan as of the date of
          his reemployment.  In the event such Participant does incur a Break in
          Service Year, he shall be eligible again to actively participate in
          this Plan retroactive to his date of reemployment after he has again
          satisfied the eligibility requirement of Section 3.1(a).

     4.   SECTION 4.11(a)(2) SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

               (2) The Average Contribution Percentage for Highly Compensated
          Employees who are eligible to participate for the Plan Year shall not
          exceed the Average Contribution Percentage for Nonhighly Compensated
          Employees who are eligible to participate for the Plan Year multiplied
          by two (2), and the Average Contribution Percentage for such Highly
          Compensated Employees shall not exceed the Averge Contribution
          Percentage for such Nonhighly Compensated Employees by more than two
          percentage points or such lesser amount as the Secretary of Treasury
          shall prescribe by regulations in accordance with Code Section
          401(m)(9) to prevent the multiple use of this alternative limitation
          with respect to any Highly Compensated Employees, which regulations
          are incorporated herein by reference.  Any such restriction on the
          multiple use of the alternative limit shall apply to all affected
          Highly Compensated Employees and shall be implemented pursuant to
          uniform rules adopted by the Committee.

      5.  SECTION 4.13(a)(4) SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

               (4) amounts described in Code Sections 415(l)(2) and
          419(A)(d)(3).

     6.   SECTION 4.13(a)(B) SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

               (B) any amount otherwise treated as an Annual Addition under Code
          Section 415(l)(2).

     7.   SECTION 8.3 SHALL BE AMENDED THROUGH THE ADDITION OF THE FOLLOWING:

               To the extent any Employer securities held by the Plan are not
          readily tradable on an established securities market, valuation of
          such securities shall be


                                      -2-

<PAGE>   128
          made by an independent appraiser who meets requirements similar to the
          requirements of the regulations prescribed under Code Section
          170(a)(1).

     8.   SECTION 9.7(a)(1) OF THE PLAN SHALL BE AMENDED IN ITS ENTIRETY TO READ
AS FOLLOWS:

               (1) If the vested portion of a Participant's Plan Account has
          ever exceeded $3,500, no distribution shall be made to such
          Participant pursuant to Section 9.1, 9.2, 9.7(c)(2), or 9.9 prior to
          the date the Participant attains the age of sixty-five (65) without
          written consent of the Participant; and

     9.   SECTION 9.7 OF THE PLAN SHALL BE AMENDED THROUGH THE ADDITION OF A NEW
SUBSECTION (e) THERETO, WHICH SHALL READ AS FOLLOWS:

               (e) Distribution hereunder must begin not later than the sixtieth
          (60th) day after the close of the Plan Year in which occurs the latest
          of (a) the Participant's termination of employment, (b) the
          Participant's attainment of age sixty-five (65), or (c) the tenth
          (10th) anniversary of the date the Participant first became a
          Participant, unless (1) the Participant elects a later date by
          submitting to the Company a written statement signed by the
          Participant which describes the benefit and the date on which payment
          of such benefit shall commence, so long as such election does not
          violate the incidental benefit rule prescribed by the Code; or (2) if
          the amount of the payment required to commence on the date determined
          hereinabove cannot be ascertained by such date, or if it is not
          possible to make such payment on such date because the Company has
          been unable to locate the Participant after making reasonable efforts
          to do so, a payment retroactive to such date may be made no later than
          sixty (60) days after the earliest date on which the amount of such
          payment can be ascertained under the Plan or the date on which the
          Participant is located, whichever is applicable.  For purposes of this
          subsection, the failure of a Participant to consent to a distribution
          shall be deemed an election to defer commencement of payment of any
          benefit sufficient to satisfy this section.

     10.  SECTION 9.8 OF THE PLAN SHALL BE AMENDED THROUGH THE ADDITION OF THE
FOLLOWING LANGUAGE AT THE END THEREOF:

               The distribution requirements of Code Section 409(o) shall be met
          by the Plan, to the extent applicable.


                                     -3-
<PAGE>   129

     11.  SECTION 9.9(a) OF THE PLAN SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

               (a) Normal Form.  Notwithstanding any provision of the Plan,
          other than the final paragraph of section 9.7(a), if a distribution is
          to be made under section 9.1(a) or (c) and the Participant has a Fixed
          Income fund account and at least one Hour of Employment prior to May
          31, 1988, then unless the Participant or legal representative shall
          make an election in the manner prescribed in section 9.9(b), the value
          of such account (exclusive of the portion thereof attributable to
          diversification elections under section 14.5) shall be distributed by
          the purchase of an immediately payable single premium annuity contract
          providing for monthly payments during the Participant's lifetime and,
          if the Participant is married on the date payment of his benefit
          commences and his spouse shall survive him, for monthly payments
          during the remainder of such spouse's lifetime, each such payment to
          such spouse being equal to one-half of the monthly payment received by
          the Participant, commencing no later than March 1 of the calendar year
          following the calendar year of the Participant's termination of
          employment, and delivery of such contract to the Participant within a
          reasonable time after the Participant's termination of employment.

               If a distribution is to be made under section 9.1(b) because of a
          Participant's death and the Participant had a Fixed Income fund
          account at the time of his death and at least one Hour of Employment
          prior to May 31, 1988, then unless the Participant had made or the
          Participant's spouse or beneficiary, as the case may be, makes an
          election at the time and in the manner prescribed in section 9.9(b),
          the value of the Participant's Fixed Income fund account (exclusive of
          the portion thereof attributable to diversification elections under
          section 14.5) shall be distributed by purchase of an immediately
          payable single premium annuity contract providing for monthly payments
          to the Participant's spouse, or, if the Participant was not married on
          the day of his death, to his beneficiary during such person's
          lifetime, commencing no later than March 1 of the calendar year
          following the calendar year of the Participant's death and delivery of
          such contract to such person within a reasonable time after the date
          of Participant's death.

     12.  THE SECOND PARAGRAPH OF SECTION 9.9(b) SHALL BE AMENDED THROUGH THE
ADDITION OF THE FOLLOWING AT THE END THEREOF:


                                     -4-


<PAGE>   130
               In all cases, such notice shall be provided no less than thirty
          (30) days and no more than ninety (90) days prior to the annuity
          starting date.

     13.  A NEW SECTION 9.15 SHALL BE ADDED TO THE PLAN WHICH SHALL READ AS
FOLLOWS:

               Notwithstanding anything herein to the contrary, a Participant's
          Salary Reduction contributions shall not be distributed prior to the
          Employee's retirement, death, disability, termination of employment,
          or hardship, except that a distribution of such amounts may be made,
          in accordance with Code Section 401(k)(10), upon

               (a) termination of the Plan without establishment of another
          defined contribution plan other than an employee stock ownership plan
          (as defined in Code Section 4975(e) or 409) or a simplified employee
          pension plan (as defined in Code Section 408(k));

               (b) the disposition by MCN Corporation or the Company to an
          unrelated corporation of substantially all of the assets (as defined
          in Code Section 409(e)(2)) used in the trade or business if the
          Company continues to maintain the Plan after the disposition, but only
          with respect to employees who continue employment with the corporation
          acquiring such assets; or

               (c) the disposition by MCN Corporation or the Company to an
          unrelated entity of its interest in a subsidiary (within the meaning
          of Code Section 409(d)(3)) if the Company continues to maintain the
          Plan, but only with respect to employees who continue employment with
          such subsidiary.

     14.  SECTION 13.2(e)(1) SHALL BE REVISED IN ITS ENTIRETY AS FOLLOWS:

               (1) Is one of the fifty (50) (or if fewer, the greater of three
          (3) or ten percent (10%) of all Employees) officers of the Employer
          who had the largest Compensation in the five-year period ending on the
          last day of the current Plan Year, but only if such officer's
          Compensation exceeds one-half of the dollar limitation of Code Section
          415(b)(1)(A) for the calendar year in which the Determination Date
          falls.

     15.  SECTION 13.3(b) OF THE PLAN SHALL BE AMENDED THROUGH THE ADDITION OF A
NEW PARAGRAPH (e) THERETO, WHICH SHALL READ AS FOLLOWS:


                                      -5-

<PAGE>   131

               (E) The account balances and accrued benefits of a Participant
          (1) who is not a Key Employee but who was a Key Employee in a prior
          year or (2) who has not been credited with at least one Hour of
          Service with any Employer at any time during the five-year period
          ending on the Determination Date will be disregarded.

     16.  SECTION 13.4(c) SHALL BE AMENDED THROUGH THE ADDITION OF THE FOLLOWING
AT THE END OF THE FIRST PARAGRAPH THEREOF:

               Salary Reduction contributions will not be treated as Employer
          contributions for purposes of satisfying the minimum allocation, but
          will be included for purposes of determining whether a Key Employee
          has received an Employer contribution of at least three percent (3%).

     17.  Other than as provided herein, the Plan shall remain unchanged.

     IN WITNESS WHEREOF, this Amendment has been executed as of this _____ day
of __________, 1994.

                                             MICHIGAN CONSOLIDATED GAS COMPANY



                                             By   /s/ Susan K. McNish
                                                  --------------------------
                                              Its  General Counsel & Secretary
                                                   ---------------------------


                                     -6-

<PAGE>   132
                            SECOND AMENDMENT TO THE
                     1989 AMENDMENT AND RESTATEMENT OF THE
                    MICHCON SAVINGS AND STOCK OWNERSHIP PLAN


     WHEREAS, Michigan Consolidated Gas Company (the "Company") has previously
established the MichCon Savings and Stock Ownership Plan (the "Plan"), which was
most recently amended and restated effective January 1, 1989;

     WHEREAS, FURTHER, pursuant to Section 11.1 of the Plan, the Company has
reserved the right to amend the Plan from time to time;

     NOW, THEREFORE, the Plan is hereby amended as follows, effective January 1,
1995, except as otherwise provided below:

     1.   The first paragraph of Section 2.1(r) is amended in its entirety as
follows:

          (r) "Eligible Compensation" means the regular basic salary or wage
     paid to an Employee by the Employer before any payroll deduction for taxes
     or any other purpose, and before any Salary Reduction allotment or
     cafeteria plan election, but excluding merit, incentive and other similar
     payments made in the form of a lump sum, bonuses, awards, shift
     differentials, deferred compensation, severance payments, differential
     payments made by reason of the Employee's entry into Military Service, all
     amounts paid for work in excess of 40 hours in any one week, all overtime
     or other premium paid for work in excess of a maximum number of hours in
     any one day, for work on holidays or for any other reason, payments for
     so-called fringe benefits such as Employer contributions to this Plan or
     any pension or retirement plan, increased wages or salary resulting from
     temporary promotion, upgrading or transfer, of whatever duration, to a
     higher paid job or classification, and any other premium, auxiliary, or
     special pay of any sort whatsoever.

     2.   Section 2.1(t) is amended in its entirety as follows:

          (t) "Employee" means an individual who is an employee of the Company
     or an Affiliated Company, but shall not include an individual who enters
     into a formal or informal independent contractor agreement with the Company
     or is otherwise treated as an independent contractor under the payroll
     practices of the Company.


                                       1

<PAGE>   133

     3.   Section 3.7 is amended by adding the following at the end thereof:

          Notwithstanding anything herein to the contrary, Hours of Employment
     shall be credited hereunder at all times in compliance with the
     requirements of the Family and Medical Leave Act.

     4.   Section 4.1(a)(3) is amended in its entirety as follows, effective
March 1, 1995:

          (3) On and after September 1, 1993 (and prior to March 1, 1995 in the
     case of a Participant who is a Nonhighly Compensated Employee), 15 percent
     of his Compensation Rate, in incremental percentages of 1 percent, or

     5.   A new subsection (4) is added to Section 4.1(a) and reads as follows,
effective March 1,1995:

          (4) On and after March 1, 1995, for a Participant who is a Nonhighly
     Compensated Employee, 20 percent of his Compensation Rate, in incremental
     percentages of 1 percent.

     6.   A new subsection (4) is added to Section 4.1(b) and reads as follows,
effective March 1, 1995:

          (4) effective March 1, 1995 for Participants who are Nonhighly
     Compensated Employees, 20 percent, in incremental percentages of 1 percent
     of the Participant's prevailing Compensation Rate.

     7.   The third paragraph of Section 4.2 is amended in its entirety as
follows, effective July 1, 1995:

          For periods beginning on or after July 1, 1995, effective as of the
     first pay period following the date on which a Participant has completed 23
     Years of Service or as of July 1, 1995, if later, 6 percent shall be
     substituted for 4 percent in each place that it appears in the first
     paragraph of this section 4.2.


     8.   Section 4.3(a)(1)(B) is amended in its entirety as follows:

          (B) for periods beginning on or after July 1, 1995, the 4 percent
     shall be increased to 6 percent for Participants who have completed 23
     Years of Service.

     9.   A new subsection (d) is added to Section 4.3 and reads as follows:

          (d) Longevity Contributions.  Effective April 1, 1995, within a
     reasonable time after April 1 of each Plan Year (each a "Measurement Date")
     each 


                                       2

<PAGE>   134


          Employer shall contribute to the ESOP Account of each of its
          participating Employees on active payroll as of such Measurement Date
          who has at least 30 Years of Service as of such Measurement Date,
          twenty-five (25) shares of MCN stock (or an equivalent value
          determined by the Committee in a nondiscriminatory manner, which may
          be used to purchase MCN Stock).

     10.  The second paragraph of subsection 4.13(b) is amended in its entirety
as follows, effective January 1, 1996:

          Code section 415 shall be applied in such manner as to maximize the
     permissible contributions and benefits thereunder and, in determining the
     permissible amount of contributions under the Plan, any grandfathering
     provisions heretofore or hereafter adopted pursuant to Code section 415
     shall be applicable.  For purposes of applying the limitations set forth in
     Code section 415(e), this Plan shall be the primary plan and any required
     reductions shall be made from the MichCon Retirement Plan (or other
     applicable defined benefit plan of the Employer).

     11.  Subsection 6.1(a) is amended in its entirety as follows:

          (a) The Employer contributions made pursuant to section 4.3(a), (c),
     and (d) shall be invested in the MCN Stock Fund (through each Participant's
     ESOP Account), which fund is described in Article VII.

     12.  Subsection 8.1(c) is amended in its entirety as follows:

          (c) an ESOP Account attributable to Employer contributions under
     section 4.3(a), (c) and (d), and

     13.  Subsection 8.5(a) is amended in its entirety as follows:

          (a) the value of his ESOP Account attributable to Employer
     contributions on his behalf under section 4.3(a), (c) and (d) and shares of
     MCN Stock allocated to his ESOP Account under section 14.4(d); and

     14.  Section 9.7(a)(ii) is amended in its entirety as follows:

          (ii) such former Participant may upon 30 days' prior notice to the
     Committee receive a partial distribution rather than a total distribution,
     of the vested portion of his Account, but not more frequently than (1)
     three times in any calendar year (during the period beginning January 1,
     1995 and ending June 30, 1995) or (2) four times per year (effective July
     1, 1995), and


                                       3

<PAGE>   135

     15.  Section 14.2(a) is amended in its entirety as follows:

          (a) the Employer contributions under section 4.3(a), (c) and (d)
     hereof made on behalf of such Participant;

     16.  Other than as provided herein, the Plan shall remain unchanged.


                                      4



<PAGE>   136


     IN WITNESS WHEREOF, this Amendment has been executed as of this 27th day
of December, 1995.

                
                             MICHIGAN CONSOLIDATED GAS COMPANY



                             By /s/ Susan K. McNish
                                -----------------------------------

                             Its Secretary and General Counsel
                                 ----------------------------------




                                       5


<PAGE>   137

                             THIRD AMENDMENT TO THE
                     1989 AMENDMENT AND RESTATEMENT OF THE
                    MICHCON SAVINGS AND STOCK OWNERSHIP PLAN


     WHEREAS, Michigan Consolidated Gas Company (the "Company") has previously
established the MichCon Savings and Stock Ownership Plan (the "Plan"), which was
most recently restated effective January 1, 1989;

     WHEREAS, FURTHER, pursuant to Section 11.1 of the Plan, the Company has
reserved the right to amend the Plan from time to time;

     NOW, THEREFORE, the Plan is hereby amended as follows, effective January 1,
1996 except as otherwise provided below:

1.   Section 2.1(aaa) is hereby amended in its entirety as follows:

     "Valuation Date" means each business day on which the New York Stock
     Exchange shall be open for buisness.

2.   Section 4.5(a) shall be clarified by adding the following at the end
thereof, effective January 1, 1995:

     Former Employees who are Participants and who receive an eligible rollover
     distribution from another plan sponsored by an Employer may make rollover
     contributions in accordance with this section.

3.   Section 9.10(g) shall be amended in its entirety as follows:

     (g) Amounts of principal and interest received on a loan shall be credited
     to the Participant's account and the outstanding loan balance shall be
     considered an investment of the assets of the account.  Payment of
     principal and interest related to loans made from a Participant's ESOP
     Account shall be credited to such Participant's ESOP Account.  Payment of
     principal and interest related to loans made from a Participant's Savings
     Plan Account shall be credited to the Participant's Investment Plan Account
     and shall be invested in the investment funds in the same proportions as
     the investment election then in effect by the Participant under Article VI.


                                       1

<PAGE>   138


4.   Section 10.1(a) shall be amended in its entirety as follows:

     (a)  The Company shall appoint a Committee consisting of at least three
     members which shall be known as the Master Trust, Retirement and Savings
     Plan Committee (the "Committee") and which shall be responsible (except for
     duties specifically vested in the Trustee) for the administration of the
     provisions of the Plan.

5.   A new Section 15.9 shall be added to the plan, effective October 12, 1996,
which shall read as follows:

     15.9 USERRA Rights.  Notwithstanding any provision of the Plan to the
     contrary, contributions, benefits and service credit with respect to
     qualified military service will be provided in accordance with Code Section
     414(u), to the extent applicable.  Loan repayments will be suspended under
     this Plan as permitted under Code Section 414(u).


6.   A new Article  XVI shall be added to the plan, effective as of January 1,
1996 provided that a favorable private letter ruling in connection with this
addition is received from the Internal Revenue Service on or before January 31,
1997, and which is otherwise effective on January 1 of the year in which such
favorable private letter ruling is received, which such Article XVI shall read
as follows:

                      Article XVI.  Redesignation of ESOP

     This Article XVI designates that part of the non-ESOP portion of the plan
     which is invested in the MCN Stock Fund becomes part of the ESOP portion of
     the Plan.  This Article XVI also sets forth certain provisions regarding
     the operation of the ESOP portion of the Plan, such provisions to supersede
     any contrary provisions of the Plan.

     Except as specifically provided in this Article XVI, the provisions of this
     Article XVI, including the redesignation of the ESOP portion of the Plan
     described herein, shall not affect any beneficiary designations or any
     other applicable agreements, elections, or consents that Participants,
     spouses, or beneficiaries validly executed under the terms of the Plan
     before the execution date of the Plan amendment which first adopts this
     Article XVI, and such designations, agreements, elections and consents
     shall continue to apply in the same manner as they did prior to such
     amendment.

     The ESOP, as set forth in this Article XVI, is intended to meet with
     requirements of an employee stock ownership plan, as defined in Section
     4975(e)(7) of the Code and the accompanying regulations, and Section
     407(d)(6) of ERISA.  As provided below, the ESOP is designed to invest
     primarily in qualifying employer securities of MCN Corporation.


                                      2


<PAGE>   139

16.1 REDESIGNATION OF ESOP PORTION OF PLAN.  Effective as of January 1, 1996, 
the  ESOP portion of the Plan shall consist of the ESOP  Account of each
Participant plus the remaining part of each  Participant's Plan Account that is
invested in the MCN Stock Fund. The put option provisions of Section 14.6 shall
apply to the entire ESOP portion of the Plan.  However, only a Participant's
ESOP Account shall be subject to the restrictions described in the first
sentence of Section 6.3.

16.2 ALLOCATION OF SAVINGS PLAN ACCOUNT BALANCES TO ESOP PORTION OF PLAN. 
On and after January 1, 1996, all amounts contributed, transferred or
designated as allocable to the Savings Plan Account of any Participant shall be
treated as part of the ESOP portion of the Plan to the extent the Participant
has directed the investment of such amounts in the MCN Stock Fund in accordance
with Article VI of the Plan.

16.3 DISTRIBUTION OF DIVIDENDS ON MCN STOCK.  At the direction of the
Committee exercised in its sole discretion, the Trustee will, after dividends
are paid on MCN Stock held in the Trust, but in no event later than 90 days
following the end of the Plan Year in which such dividends are paid (to the
extent such dividends are not used to make payment on an exempt loan as
provided for in section 14.4(c) of the Plan), either (i) distribute to
Participants such portion of the dividends attributable to the interests in MCN
Stock held in their Plan Accounts (or, if  so determined by the Committee,
their ESOP Accounts) as described below or, (ii)  arrange to have such
dividends distributed directly to Participants by the Employer, or (iii)
arrange to have such dividends distributed to Participants by a dividend
disbursement agent selected by the Committee, which may be the Employer's
payroll department.  In its sole discretion, the Committee may direct the
Trustee to have such dividends distributed only to Participants who elect to
receive such dividend distributions in accordance with procedures established
by the Committee (which such procedures may apply to all Participants, solely
to Participants described in (a) below, or solely to Participants not described
in (a) below).  Further, in its sole discretion, the Committee may establish
procedures that would permit Participants to elect to have dividends
distributed to them in a single sum rather than over periods that might
otherwise be determined by the Committee to correspond with Employer payroll
practices.

     The distribution of dividends on MCN Stock held in a Participant's Plan
Account (or, if so determined by the Committee, a Participant's ESOP Account )
shall be in the following amounts:

     a.   Participants who have terminated employment with the Employers
          and all other nonemployees with Plan Account balances (such as QDRO
          alternate payees and beneficiaries of deceased Participants) shall
          receive distributions of all of the dividends paid on the MCN Stock
          held in their Plan Accounts (or, if so determined by the Committee,
          their ESOP Accounts), provided, however, that the aggregate amount of
          such distributions to each such Participant or other individual shall
          not exceed 

                                      3


<PAGE>   140

          $3,500 in any Plan Year (unless the Committee, in its sole
          discretion, uniformly permits such Participants to elect to receive
          such distributions without limitation).

     b.   Participants who are employees who participate in the MCN
          Supplemental Savings Plan shall receive distributions of all of
          the dividends paid on the MCN Stock held in their Plan Accounts
          (or, if so determined by the Committee, their ESOP Accounts).

     c.   Each other Participant not described in (a) or (b) above shall
          receive distributions equal to the amount of Additional
          Allotments that he or she would be permitted to make under
          Section 16.4 below, subject to the limitations of Section 16.5
          below, unless such Participant affirmatively elects to receive a
          distribution of 100% of the dividends paid on the MCN Stock held
          in his or her Plan Account (or, if so determined by the
          Committee, his or her ESOP Account).

     For purposes of this Section 16.3, the ESOP portions of both the
MichCon Savings and Stock Ownership Plan and the MichCon Investment and Stock
Ownership Plan shall be considered in the aggregate for each Participant and
the payment of dividend amounts on MCN Stock held in the Plan Accounts (or, if
so determined by the Committee, the ESOP Accounts) under both plans shall not
exceed the limitations on distributions of dividends set forth in subsections
(a) and (c) above. In this regard, the limitations under subsections (a) and
(c) shall be allocated among the two plans for a Participant by multiplying
such limitation by a percentage derived by dividing the total of ESOP portion
under each plan by the total ESOP portions under both plans (or, if so
determined by the Committee, by dividing the total ESOP Account under each plan
by the total ESOP Account under both plans).

16.4 ADDITIONAL ALLOTMENTS.  All active Employee-Participants will be deemed 
to have elected to make additional Salary Reduction allotments similar to 
those elected under Section 4.1 ("Additional Allotments") for each calendar
year unless they affirmatively elect (under procedures established by the
Committee) not to make such allotments at least 15 days prior to the scheduled
commencement of any distributions under  Section 16.3 above (the "Election
Date"). The amount of Additional Allotments deemed to be elected under this
Section 16.4 shall be equal to the amount of ESOP dividends distributed to the
Participant under Section 16.3 above, but subject to applicable legal
limitations, including but not limited to the restrictions of Code Sections
402(g) and 415.  Such restrictions shall be applied in the manner determined by
the Committee in its sole discretion .  The amount of Additional Allotments
shall be calculated by the Committee utilizing uniform methodologies and
assumptions established by the Committee in its sole discretion.


                                      4

<PAGE>   141


16.5 PROVISIONS FOR FURTHER REDUCTION OF ADDITIONAL ALLOTMENTS.  A
Participant's Additional Allotments shall be further reduced as necessary below
the level described in Section 16.4 above so as to limit Additional Allotments
to an amount equal to or not exceeding:

     a.   The lesser of (i) the residual of a Participant's gross wages
          less all deductions other than Additional Allotments or (ii) the
          maximum further reduction permitted under applicable law.

     b.   Zero, in the event that the Participant does not make allotments
          pursuant to Section 4.1 of the Plan at the time of any
          distribution of dividends pursuant to Section 16.3 above.

     c.   Zero, in the event that the Participant's Plan Account is
          invested in  less than one share of MCN Stock immediately prior
          to the distribution of dividends.

16.6 EMPLOYER CONTRIBUTIONS. Additional Allotments shall not be subject
to the  limitations on Salary Reduction and Voluntary Deduction allotments
described in Section 4.1.  In addition, Additional Allotments shall not be
treated as Salary Reduction or Voluntary Deduction allotments under Section 4.1
for the purposes of determining Employer contributions under 4.2 and 4.3 of the
Plan, and shall be disregarded for these purposes.


     IN WITNESS WHEREOF, this Amendment has been executed as of this 23rd day of
December, 1996.

                             MICHIGAN CONSOLIDATED GAS COMPANY



                             By   /s/ Susan K. McNish
                                  ---------------------------------------------
                               Its  Vice President, General Counsel & Secretary
                                  ---------------------------------------------

 
                                      5