<PAGE>   1
                                                                    EXHIBIT 3-1





                               STATE OF MICHIGAN
                             DEPARTMENT OF COMMERCE
                       CORPORATION AND SECURITIES BUREAU
                              CORPORATION DIVISION
                               LANSING, MICHIGAN



                               MCN CORPORATION

                          ARTICLES OF INCORPORATION




                                  FILED

                             AUGUST 12, 1988

                              Administrator
                     MICHIGAN DEPARTMENT OF COMMERCE
                     Corporation & Securities Bureau





       IDENTIFICATION NUM       381 - 153
                                                                      

<PAGE>   2

                           ARTICLES OF INCORPORATION
                                       OF
                                MCN CORPORATION


Pursuant to the provisions of Act 284, Public Acts of 1972, as amended, the
undersigned corporation executes the following Articles:

         FIRST.  The name of the corporation is MCN Corporation

         SECOND.  The purpose or purposes for which the Corporation is
organized is to engage in any activity with in the purposes for which
corporations may be organized under the Michigan Business Corporation Act.

         THIRD.  The total number of shares of all classes of stock which the
Corporation shall have authority to issue is 75,000,000 shares, which shall be
divided into two classes as follows:

         (a)     25,000,000 shares of Preferred Stock, no par value (Preferred 
                 Stock); and

         (b)     50,000,000 shares of Common Stock of the par value of $.01 
                 per share (Common Stock).

         The designations, voting powers, preferences and relative,
participating, optional or other special rights, and the qualifications,
limitations or restrictions of the above classes of stock and other general
provisions relating thereto shall be as follows:


                                     PART I
                                PREFERRED STOCK

         (a)     Shares of Preferred Stock may be issued in one or more series
at such time or times and for such consideration or considerations as the Board
of Directors may determine.  All shares of any one series shall be of equal
rank and identical in all respects expect that the dates from which dividends
accrue or accumulate with respect thereto may vary.

         (b)     The Board of Directors is expressly authorized at any time,
and from time to time, to provide for the issuance of shares of Preferred Stock
in one or more series, with such voting powers, full or limited, or without
voting





                                       2
<PAGE>   3


powers, and such designations, preferences and relative, participating,
optional or other special rights and qualifications, limitations or
restrictions thereof, as shall be stated and expressed in the resolution or
resolutions providing for the issue thereof adopted by the Board of Directors,
and as are not stated and expressed in these Articles of Incorporation, or any
amendment thereto, including (but without limiting the generality of the
foregoing) the following:

       (i)       The distinctive designation and number of shares comprising
                 such series, which number may (except where otherwise provided
                 by the Board of Directors in creating such series) be
                 increased or decreased (but not below the number of shares
                 then outstanding) from time to time by action of the Board of
                 Directors.

      (ii)       The dividend rate or rates on the shares of such series and
                 the relation which such dividends shall bear to the dividends
                 payable on any other class of capital stock or on any other
                 series of Preferred Stock, the terms and conditions upon which
                 and the periods in respect of which dividends shall be
                 payable, whether and upon what conditions such dividends shall
                 be cumulative and, if cumulative, the date or dates from which
                 dividends shall accumulate.

     (iii)       Whether the shares of such series shall be redeemable, and, if
                 redeemable, whether redeemable for cash, property or rights,
                 including securities of any other corporation, at the option
                 of either the holder or the Corporation or upon the happening
                 of a specified event, the limitations and restrictions with
                 respect to such redemption, the time or times when, the price
                 or prices or rate or rates at which, the adjustments with
                 which and the manner in which such shares shall be redeemable,
                 including the manner of selecting shares of such series for
                 redemption if less than all shares are to be redeemed.

       (iv)      The rights to which the holders of shares of such series shall
                 be entitled, and the preferences, if any, over any other
                 series (or of any other series over such series), upon the
                 voluntary or involuntary liquidation, dissolution,
                 distribution or winding up of the Corporation, which rights
                 may vary depending on whether such liquidation, dissolution,
                 distribution or winding up is voluntary or involuntary, and,
                 if voluntary, may vary at different dates.





                                       3
<PAGE>   4


        (v)      Whether the shares of such series shall be subject to the
                 operation of a purchase, retirement or sinking fund and, if
                 so, whether and upon what conditions such purchase, retirement
                 or sinking fund shall be cumulative or noncumulative, the
                 extent to which and the manner in which such fund shall be
                 applied to the purchase or redemption of the shares of such
                 series for retirement or to other corporate purposes and the
                 terms and provisions relative to the operation thereof.

       (vi)      Whether the shares of such series shall be convertible into or
                 exchangeable for shares of any other class or of any other
                 series of any class of capital stock of the Corporation, and,
                 if so convertible or exchangeable, the price or prices or the
                 rate or rates of conversion or exchange and the method, if
                 any, of adjusting the same, and any other terms and conditions
                 of such conversion or exchange.

      (vii)      The voting powers, full and/or limited, if any, of the shares
                 of such series, and whether and under what conditions the
                 shares of such series (along or together with the shares of
                 one or more other series having similar provisions) shall be
                 entitled to vote separately as a single class, for the
                 election of one or more additional directors of the
                 Corporation in case of dividend arrearages, or other specified
                 events, or upon other matters.

     (viii)      Whether the issuance of any additional shares of such series,
                 or of any shares of any other series, shall be subject to
                 restrictions as to issuance or as to the powers, preferences
                 or rights of any such other series.

       (ix)      Any other preferences, privileges and powers and relative,
                 participating, optional or other special rights, and
                 qualifications, limitations or restrictions of such series, as
                 the Board of Directors may deem advisable and as shall not be
                 inconsistent with the provisions of these Articles of
                 Incorporation.

         (c)     Unless the except to the extent otherwise required by law or
provided in the resolution or resolutions of the Board of Directors creating
any series of Preferred Stock pursuant to this Part I, the holders of the
shares of Preferred Stock shall have no voting power with respect to any matter





                                       4
<PAGE>   5


whatsoever.  In no event shall the Preferred Stock be entitled to more than one
vote in respect to each share of Preferred Stock.

         (d)     Shares of Preferred Stock redeemed, converted, exchanged,
purchased, retired or surrendered to the Corporation, or which have been issued
and reacquired in any manner, may, upon compliance with any applicable
provisions of the Michigan Business Corporation Act, be given the status of
authorized and unissued shares of Preferred Stock and may be reissued by the
Board of Directors as part of the series of which they were originally a part
or may be reclassified into and reissued as part of a new series or as a part
of any other series, all subject to the protective conditions or restrictions
of any outstanding series of Preferred Stock.


                                    PART II
                                  COMMON STOCK

         (a)     Except as otherwise required by law or by any amendment to
these Articles of Incorporation, each holder of Common Stock shall have one
vote for each share of Common Stock held by such holder on all matters voted
upon by the shareholders.

         (b)     Subject to the preferential dividend rights, if any,
applicable to shares of Preferred Stock and subject to applicable requirements,
if any, with respect to the setting aside of sums of purchase, retirement or
sinking funds for Preferred Stock, the holders of Common Stock shall be
entitled to receive, to the extent permitted by law, such dividends as may be
declared from time to time by the Board of Directors.





                                       5
<PAGE>   6

                                    PART III
                               GENERAL PROVISIONS

         No holder of stock of any class of the Corporation shall be entitled
as a matter of right to purchase or subscribe for any part of any unissued
stock of any class, or of any additional stock of any class of capital stock of
the Corporation, or of any bonds, certificates of indebtedness, debentures, or
other securities, whether or not convertible into stock of the Corporation, now
or hereafter authorized, but any such stock or other securities may be issued
and disposed of pursuant to resolution by the Board of Directors to such
persons, firms, corporations or associations and upon such terms and for such
consideration (not less than the par value or stated value thereof) as the
Board of Director in the exercise of its discretion may determine and as may be
permitted by law without action by the shareholders.  The Board of Directors
may provide for payment therefor to be received by the Corporation in cash,
personal property, real property (or leases thereof) or services.  Any and all
shares of stock so issued for which the consideration so fixed has been paid or
delivered, shall be deemed fully paid and not liable to any further call or
assessment.

         FOURTH.

         (a)     The address of the registered office of the Corporation is 500
Griswold Street, Detroit, Michigan 48226.

         (b)     The name of the registered agent at the registered office is
Daniel L. Schiffer.

         FIFTH.  The name and address of the incorporator is as follows;

Name                                                    Address

Michigan Consolidated Gas Company                500 Griswold Street
                                                 Detroit, Michigan 48226

         SIXTH.

         (a)     The business and affairs of the Corporation shall be managed
by or under the direction of a Board of Directors.  The number of directors of
the Corporation shall be fixed from time to time by resolution adopted by the
affirmative vote of a majority of the entire Board of Directors of the
Corporation, except that the minimum number of directors shall be fixed at not





                                       6
<PAGE>   7


fewer than seven and the maximum number of directors shall be fixed at not more
than ten.  The directors shall be divided into three classes, designated as
Class I, Class II and Class III.  Each class shall consist, as nearly as may be
possible, of one-third of the total number of directors constituting the entire
Board of Directors.  At the 1989 annual meeting of shareholders and at each
succeeding annual meeting of shareholders, successors to the class of directors
whose terms of office expire at that annual meeting shall be elected to hold
office for a three-year term, so that the term of office of one class of
directors shall expire in each year.

         Any vacancy occurring on the Board of Directors through death,
resignation, retirement, disqualification, removal or other cause, or resulting
from an increase, the number of directors, may be filled by the affirmative
vote of a majority of the then remaining directors, through less than a quorum,
or by the sole remaining director for a term of office continuing only until
the next election of directors by the shareholders.

         If the number of directors is changed, any increase or decrease shall
be apportioned among the classes of directors so as to maintain the number of
directors in each class as nearly equal as possible, but in no case will a
decrease in the number of directors shorten the term of any incumbent director.
When the number of directors is increased by the Board of Directors and any
newly created directorships are filled by the Board of Directors, there shall
be no classification of the additional directors until the next election of
directors by the shareholders.

         (b)     Any director may be removed from office at any time either (i)
by vote of the holders of two-thirds of the shares entitled to vote at an
election of directors, but only for cause, or (ii) by vote of two-thirds of the
other directors, with or without cause.

         (c)     Notwithstanding the foregoing paragraphs, whenever the holders
of any one or more class or series of Preferred Stock issued by the Corporation
shall have the right, voting separately by class or series, to elect directors
at an annual or special meeting of shareholders, the election, term of office,
filling of vacancies and other features of such directorships shall be governed
by the terms of the Articles of Incorporation applicable thereto.  The then
authorized number of directors of the Corporation shall be increased by the
number of additional directors to be elected, and such directors so elected
shall not be divided into classes pursuant to this Article SIXTH unless
expressly provided by such terms.





                                       7
<PAGE>   8


         (d)     Nominations for election to the Board of Directors of the
Corporation at a meeting of shareholders may be made by the Board of Directors,
on behalf of the Board of Directors by any nominating committee appointed by
the Board of Directors, or by any shareholder of the Corporation entitled to
vote for the election of directors at a meeting.  Nominations, other than those
made by or on behalf of the Board of Directors, shall be made by notice in
writing delivered to or mailed, postage prepaid, and received by the Secretary
of the Corporation at least 90 days but no more than 120 days prior to the
anniversary date of the immediately preceding annual meeting of shareholders.
The notice shall set forth (i) the name and address of the shareholder who
intends to make the nomination; (ii) the name, age, business address and, if
known, residence address of each nominee; (iii) the principal occupation or
employment of each nominee; (iv) the number of shares of stock of the
Corporation which are beneficially owned by each nominee and by the nominating
shareholder; (v) any other information concerning the nominee that must be
disclosed of nominees in proxy solicitations pursuant to Regulation 14A of the
Securities Exchange Act of 1934 (or any subsequent provisions replacing such
Regulation); and (vi) the executed consent of each nominee to serve as a
director of the Corporation, if elected.  The chairman of the meeting of
shareholders may, if the facts warrant, determine that a nomination was not
made in accordance with the foregoing procedures, and if the chairman should so
determine, the chairman shall so declare to the meeting and the defective
nomination shall be disregarded.

         SEVENTH.  Any action required to permitted to be taken by any
shareholders of the Corporation must be effected at a duly called annual or
special meeting of such shareholders and may not be effected by any consent in
writing by such shareholders.  Except as may be otherwise required by law,
special meetings of shareholders of the Corporation may be called only by the
Board of Directors pursuant to a resolution approved by a majority of the Board
of Directors.

         EIGHTH.  The Board of Directors shall not approve, adopt or recommend
any proposal to enter into a Business Combination (as hereinafter defined) or
any offer of any person or entity, other than the Corporation, to make a tender
or exchange offer for any capital stock of the Corporation, unless and until
the Board of Directors shall first establish a procedure for evaluating, and
shall have evaluated, the proposal or offer and determine that it would be in
compliance with all applicable laws and in the best interests of the
Corporation and its shareholders.  In connection with its evaluation, the Board
of Directors may seek and obtain the advice of independent investment counsel,
may seek and rely upon an opinion of legal counsel and other independent





                                       8
<PAGE>   9


advisers, and may test such compliance with laws in any state or federal court
or before any state or federal administrative agency which may have appropriate
jurisdiction.  In connection with its evaluation as to the best interests of
the Corporation and its shareholders, the Board of Directors shall consider all
factors which it deems relevant, including without limitation: (i) the adequacy
and fairness of the consideration to be received by the Corporation and/or its
shareholders considering the future prospects for the Corporation and its
business, historical trading prices of the Corporation capital stock, the price
that might be achieved in a negotiated sale of the Corporation as a whole, and
premiums over trading prices which have been proposed or offered with respect
to the securities of other companies in the past in connection with similar
offers; (ii) the business, financial condition and earnings prospects of the
acquiring person or entity and the competence, experience and integrity of the
acquiring person or entity and its management; and (iii) the potential social
and economic impact of the offer and its consummation upon the Corporation's
customers, the communities in which the Corporation operates or is located and
upon the Corporation's employees, other than its officers.

         The term "Business Combination" shall mean any merger or consolidation
of the Corporation with any other person or entity.

         NINTH.  A director of the Corporation shall not be personally liable
to the Corporation  or its shareholders for monetary damages for breach of
fiduciary duty as a director, except for liability for (i) any breach of the
director's duty of loyalty to the Corporation or its shareholders, (ii) acts or
omissions not in good faith or that involve international misconduct or a
knowing violation of law, (iii) a violation of Section 551(1) of the Michigan
Business Corporation Act, or (iv) any transaction from which the director
derived an improper personal benefit.  If the Michigan Business Corporation Act
is amended after the date of these Articles of Incorporation to authorize
corporate action further eliminating or limiting the personal liability of
directors, then the liability of a director of the Corporation shall be
eliminated or limited to the fullest extent permitted by the Michigan Business
Corporation Act, as so amended.

         Any repeal or modification of the foregoing paragraph by the
shareholders of the Corporation shall not adversely affect any right or
protection of a director of the Corporation existing at the time of such repeal
or modification.

         TENTH.  The Corporation shall have perpetual existence.





                                       9
<PAGE>   10


         ELEVENTH.  The Corporation reserves the right to amend, alter, change
or repeal any provisions contained in these Articles of Incorporation, in the
manner now or hereafter prescribed by the laws of Michigan, and all rights
conferred herein upon shareholders and directors are granted subject to this
reservation.  Notwithstanding the foregoing as well as any other provision
contained in these Articles of Incorporation, any agreement with any national
securities exchange or any provision of law which might otherwise permit a
lesser vote or no vote, but in addition to any affirmative vote required by any
other provision of these Articles of Incorporation, any agreement with any
national securities exchange or any provision of law, the affirmative vote of
the holders of at least two-thirds of the votes entitled to be cast by the
holders of all the then outstanding shares of the Corporation, voting together
as a single class, shall be required to amend or repeal Articles SIXTH,
SEVENTH, EIGHTH, or this Article ELEVENTH of these Articles of Incorporation or
adopt any provision inconsistent therewith.

         The incorporator signs its name this 12th day of August, 1988.



                                    MICHIGAN CONSOLIDATED GAS COMPANY



                                    By: /s/ Alfred R. Glancy III
                                        ----------------------------------
                                        Alfred R. Glancy III 
                                        Chairman and Chief Executive Officer





                                       10
<PAGE>   11




     MICHIGAN DEPARTMENT OF COMMERCE - CORPORATION AND SECURITIES BUREAU

                                         FILED

                                   DECEMBER 28, 1989

                                     Administrator
                            MICHIGAN DEPARTMENT OF COMMERCE
                            Corporation & Securities Bureau





          CERTIFICATE OF AMENDMENT TO THE ARTICLES OF INCORPORATION

                      For use by Domestic Corporations
           (Please read information and instructions on last page)


        Pursuant to the provisions of Act 284, Public Acts of 1972 (profit
corporations), or Act 162, Public Acts of 1982 (nonprofit corporations), the
undersigned corporation executes the following Certificate:


1.  The present name of the corporation is:  MCN Corporation
2.  The corporation identification number (CID) assigned by
    the Bureau is:                                              381  -  153
      

3.  The location of its registered office is:

      500 Griswold          Detroit, Michigan  48226
    



4.  Article    Third         of the Articles of Incorporation is hereby 
    amended to read

add thereto the Certificate of Establishment and Designation of Junior 
Participating Preferred Stock, Series A of MCN Corporation in the form 





<PAGE>   12

           attached hereto as Exhibit A.

<PAGE>   13


  5.   COMPLETE SECTION (a) IF THE AMENDMENT WAS ADOPTED BY THE UNANIMOUS
       CONSENT OF THE INCORPORATOR(S) BEFORE THE FIRST MEETING OF THE BOARD OF
       DIRECTORS OR TRUSTEES; OTHERWISE, COMPLETE SECTION (B)



  b.   [X]  The foregoing amendment to the Articles of Incorporation was
            duly adopted on the 20th day of December, 1989.  The amendment: 
            (check one of the following)


       [X]  was duly adopted in accordance with Section 302 of the Act by the
            Board of Directors.



                                     Signed this 28th  day of December, 1989

                                     By /s/ Stephen E. Ewing
                                        --------------------------------
                                        Stephen E. Ewing, President           





<PAGE>   14




                                                                       Exhibit A

                                      FORM

                                       of

                  CERTIFICATE OF ESTABLISHMENT AND DESIGNATION

                                       of

                 JUNIOR PARTICIPATING PREFERRED STOCK, SERIES A

                                       of

                                MCN CORPORATION

                      (Pursuant to Section 450.1302 of the
                       Michigan Business Corporation Act)


       MCN Corporation, a corporation organized and existing under the Business
Corporation Act of the State of Michigan (hereinafter called the
"Corporation"), hereby certifies that the following resolution was adopted by
the Board of Directors of the Corporation as required by Section 450.1302 of
the Michigan Business Corporation Act at a meeting duly called and held on
December 20, 1989;

       RESOLVED, that pursuant to the authority granted to and vested in the
Board of Directors of this Corporation (hereinafter called the "Board of
Directors" or the "Board") by the provisions of the Articles of Incorporation
of the Corporation, the Board of Directors hereby establishes a series of
Preferred Stock, without par value (the "Preferred Stock"), of the Corporation
and hereby states the designation and number of shares, and prescribes the
relative rights and preferences thereof as follows:

       Junior Participating Preferred Stock, Series A:

                Section 1.  Designation and Amount.  The shares of such series
shall be designated as "Junior Participating Preferred Stock, Series A" (the
"Series A Preferred Stock") and the number of shares constituting the Series A
Preferred Stock shall be 250,000.  Such number of shares may be increased or
decreased by resolution of the Board of Directors; provided, that no decrease





                                      A-1
<PAGE>   15





shall reduce the number of shares of Series A Preferred Stock to a number less
than the number shares then outstanding plus the number of shares reserved for
issuance upon the exercise of outstanding options, rights or warrants, or the
conversion of any outstanding securities, issued by the Corporation exercisable
for or convertible into Series A Preferred Stock.

                Section 2.  Dividends and Distributions.

                (A)  Subject to the rights of the holders of any shares of any
       series of Preferred Stock (or any similar stock) ranking prior and
       superior to the Series A Preferred Stock with respect to dividends, the
       holders of shares of Series A Preferred Stock, in preference to the
       holders of Common Stock, par value $.01 per share (the "Common Stock"),
       of the Corporation, and of any other junior stock, shall be entitled to
       receive, when, as and if declared by the Board of Directors out of funds
       legally available for the purpose, quarterly dividends payable in cash
       on the first day of March, June, September and December in each year
       (each such date being referred to herein as a "Quarterly Dividend
       Payment Date"), commending on the first Quarterly Dividend Payment Date
       after the first issuance of a share or fraction of a share of Series A
       Preferred Stock, in an amount per share (rounded to the nearest cent)
       equal to the greater of (a) $1 or (b) subject to the provision for
       adjustment hereinafter set forth, 100 times the aggregate per share
       amount of all cash dividends, and 100 times the aggregate per share
       amount (payable in kind) of all non-cash dividends or other
       distributions, other than a dividend payable in shares of Common Stock
       or a subdivision of the outstanding shares of Common Stock (by
       reclassification or otherwise), declared on the Common Stock since the
       immediately preceding Quarterly Dividend Payment Date or, with respect
       to the first Quarterly Dividend Payment Date, since the first issuance
       of any share or fraction of a share of Series A Preferred Stock.  In the
       event the Corporation shall at any time declare or pay any dividend on
       the Common Stock payable in shares of Common Stock, or effect a
       subdivision or combination or consolidation of the outstanding shares of
       Common Stock (by reclassification or otherwise than by payment of a
       dividend in shares of Common Stock) into a greater or lesser number of
       shares of Common Stock, then in each such case the amount to which
       holders of shares of Series A Preferred Stock were entitled immediately
       prior to such even under clause (b) of the preceding sentence shall be
       adjusted by multiplying such amount by a fraction, the numerator of
       which is the number of shares of Common Stock outstanding immediately





                                      A-2
<PAGE>   16





       after such event and the denominator of which is the number of shares of
       Common Stock that were outstanding immediately prior to such event.

                (B)  The Corporation shall declare a dividend or distribution
       on the Series A Preferred Stock as provided in paragraph (A) of this
       Section immediately after it declares a dividend or distribution on the
       Common Stock (other than a dividend payable in shares of Common Stock);
       provided, that, in the event no dividend or distribution shall have been
       declared on the Common Stock during the period between any Quarterly
       Dividend Payment Date and the next subsequent Quarterly Dividend Payment
       Date, a dividend of $1 per share on the Series A Preferred Stock shall
       nevertheless be payable on such subsequent Quarterly Dividend Payment
       Date.

                (C)  The Dividends shall begin to accrue and be cumulative on
       outstanding shares of Series A Preferred Stock from the Quarterly
       Dividend Payment Date next preceding the date of issue of such shares,
       unless the date of issue of such shares is prior to the record date for
       the first Quarterly Dividend Payment Date, in which case dividends on
       such shares shall begin to accrue from the date of issue of such shares,
       or unless the date of issue is a Quarterly Dividend Payment Date or is a
       date after the record date for the determination of holders of shares of
       Series A Preferred Stock entitled to receive a quarterly dividend and
       before such Quarterly Dividend Payment Date, in either of which events
       such dividends shall begin to accrue and be cumulative from such
       Quarterly Dividend Payment Date.  Accrued but unpaid dividends shall not
       bear interest.  Dividends paid on the shares of Series A Preferred Stock
       in an amount less than the total amount of such dividends at the time
       accrued and payable on such shares shall be allocated pro rata on a
       share-by-share basis among all such shares at the time outstanding.  The
       Board of Directors may fix a record date for the determination of
       holders of shares of Series A Preferred Stock entitled to receive
       payment of a dividend or distribution declared thereon, which record
       date shall be not more than 60 days prior to the date fixed for the
       payment thereof.

                Section 3.  Voting Rights.  The holders of shares of Series A
Preferred Stock shall have the following voting rights:

                (A)  Each share of Series A Preferred Stock shall entitle the
       holder thereof to one vote on all matters submitted to a vote of the
       stockholders of the Corporation.





                                      A-3
<PAGE>   17





                (B)  Except as otherwise provided herein, in any other
       Certificate of Establishment and Designation establishing a series of
       Preferred Stock or any similar stock, or by law, the holders of shares
       of Series A Preferred Stock and the holders of shares of Common Stock
       and any other capital stock of the Corporation having general voting
       rights shall vote together as one class on all matters submitted to a
       vote of the stockholders of the Corporation.

                (C)  Except as otherwise provided herein, or by law, holders of
       shares of Series A Preferred Stock shall have no special voting rights
       and their consent shall not be required (except to the extent they are
       entitled to vote with holders of shares of Common Stock as set forth
       herein) for taking any corporate action.

                Section 4.  Certain Restrictions.

                (A)  Whenever quarterly dividends or other dividends or
       distributions payable on the Series A Preferred Stock as provided in
       Section 2 are in arrears, thereafter and until all accrued and unpaid
       dividends and distributions, whether or not declared, on shares of
       Series A Preferred Stock outstanding shall have been paid in full, the
       Corporation shall not:

                   (i)  declare or pay dividends, or make any other
                distributions, on any shares of stock ranking junior (either as
                to dividends or upon liquidation, dissolution or winding up) to
                the Series A Preferred Stock;

                  (ii)  declare or pay dividends, or make any other
                distributions, on any shares of stock ranking on a party
                (either as to dividends or upon liquidation, dissolution or
                winding up) with the Series A Preferred Stock, except dividends
                paid ratably on the Series A Preferred Stock and all such
                parity stock on which dividends are payable or in arrears in
                proportion to the total amounts to which the holders of all
                such shares are then entitled;

                 (iii)  redeem or purchase or otherwise acquire for
                consideration any shares of stock ranking junior (either as to
                dividends or upon liquidation, dissolution or winding up) to
                the Series A Preferred Stock; provided, that the Corporation
                may at any time redeem, purchase or otherwise acquire shares of
                such junior stock in





                                      A-4
<PAGE>   18





                exchange for shares of stock of the Corporation ranking junior
                (either as to dividends or upon liquidation, dissolution or
                winding up) to the Series A Preferred Stock; or

                  (iv)  redeem or purchase or otherwise acquire for
                consideration any shares of Series A Preferred Stock, or any
                shares of stock ranking on a parity (either as to dividends or
                upon liquidation, dissolution or winding up) with the Series A
                Preferred Stock, except in accordance with a purchase offer
                made in writing or by publication (as determined by the Board
                of Directors) to all holders of such shares upon such terms as
                the Board of Directors, after consideration of the respective
                annual dividend rates and other relative rights and preferences
                of the respective series and classes, shall determine in good
                faith will result in fair and equitable treatment among the
                respective series or classes.

                (B)  The Corporation shall not permit any subsidiary of the
       Corporation to purchase or otherwise acquire for consideration any
       shares of stock of the Corporation unless the Corporation could, under
       paragraph (A) of this Section, purchase or otherwise acquire such shares
       at such time and in such manner.

                Section 5.  Required Shares.  Any shares of Series A Preferred
Stock purchased or otherwise acquired by the Corporation in any manner
whatsoever shall be retired and canceled promptly after the acquisition
thereof.  All such shares shall upon their cancellation become authorized but
unissued shares of Preferred Stock and may be reissued as part of a new series
of Preferred Stock subject to the conditions and restrictions on issuance set
forth herein, in the Articles of Incorporation, or in any other Certificate of
Establishment and Designation establishing a series of Preferred Stock or any
similar stock or as otherwise required by law.

                Section 6.  Liquidation, Dissolution or Winding Up.  Upon any
liquidation, dissolution or winding up of the Corporation, no distribution
shall be made (1) to the holders of shares of stock ranking junior (either as
to dividends or upon liquidation, dissolution or winding up) to the Series A
Preferred Stock unless, prior thereto, the holders of shares of Series A
Preferred Stock shall have received $100 per share, plus an amount equal to
accrued and unpaid dividends and distributions thereon, whether or not
declared, to the date of such payment; provided, that the holders of shares of
Series A Preferred Stock shall be entitled to receive an aggregate amount per
share, subject to the provision for adjustment hereinafter set forth, equal to





                                      A-5
<PAGE>   19





100 times the aggregate amount to be distributed per share to holders of shares
of Common Stock, or (2) to the holders of shares of stock ranking on a parity
(either as to dividends or upon liquidation, dissolution or winding up) with
the Series A Preferred Stock, except distributions made ratably on the Series A
Preferred Stock and all such parity stock in proportion to the total amounts to
which the holders of all such shares are entitled upon such liquidation,
dissolution or winding up.  In the event the Corporation shall at any time
declare or pay any dividend on the Common Stock payable in shares of Common
Stock, or effect a subdivision or combination or consolidation of the
outstanding shares of Common Stock (by reclassification or otherwise than by
payment of a dividend in shares of Common Stock) into a greater or lesser
number of shares of Common Stock, then in each such case the amount to which
holders of shares of Series A Preferred Stock were entitled immediately prior
to such event under the provisio to clause (1) of the preceding sentence shall
be adjusted by multiplying such amount by a fraction, the numerator of which is
the number of shares of Common Stock outstanding immediately after such event
and the denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                Section 7.  Consolidation, Merger etc.  In case the Corporation
shall enter into any consolidation, merger, combination or other transaction in
which the shares of Common Stock are exchanged for or changed into other stock
or securities, cash and/or any other property, then in any such case each share
of Series A Preferred Stock shall at the same time be similarly exchanged for
or changed into an amount per share, subject to the provision for adjustment
hereinafter set forth, equal to 100 times the aggregate amount of stock,
securities, cash and/or any other property (payable in kind), as the case may
be, into which or for which each share of Common Stock is changed or exchanged.
In the event the Corporation shall at any time declare or pay any dividend on
the Common Stock payable in shares of Common Stock, or effect a subdivision or
combination or consolidation of the outstanding shares of Common Stock (by
reclassification or otherwise than by payment of a dividend in shares of Common
Stock) into a greater or lesser number of shares of Common Stock, then in each
such case the amount set forth in the preceding sentence with respect to the
exchange or change of shares of Series A Preferred Stock  shall be adjusted by
multiplying such amount by a fraction, the numerator of which is the number of
shares of Common Stock outstanding immediately after such event and the
denominator of which is the number of shares of Common Stock that were
outstanding immediately prior to such event.

                Section 8.  No Redemption.  The shares of Series A Preferred
Stock shall not be redeemable.





                                      A-6
<PAGE>   20





                Section 9.  Rank.  The Series A Preferred Stock shall rank,
with respect to the payment of dividends and the distribution of assets, junior
to all series of any other class of the Corporation's Preferred Stock.

                Section 10.  Amendment.  The Articles of Incorporation of the
Corporation shall not be amended in any manner which would materially alter or
change the powers, preferences or special rights of the Series A Preferred
Stock so as to affect them adversely without the affirmative vote of the
holders of at least two-thirds of the outstanding shares of Series A Preferred
Stock, voting together as a single class.





                                      A-7
<PAGE>   21

                                      May 4, 1994

                                     Administrator
                            MICHIGAN DEPARTMENT OF COMMERCE
                            Corporation & Securities Bureau





           CERTIFICATE OF AMENDMENT TO THE ARTICLES OF INCORPORATION

                        For use by Domestic Corporations
            (Please read information and instructions on last page)

   Pursuant to the provisions of Act 284, Public Acts of 1972 (profit
corporations), or Act 162, Public Acts of 1982 (nonprofit corporations), the
undersigned corporation executes the following Certificate:


  1.  The present name of the corporation is:  MCN Corporation
  2.  The corporation identification number (CID) assigned by
      Bureau is:      381-153

  3.  The location of its registered office is:

        500 Griswold       Detroit, Michigan 48226

  4.  Article    Third   of the Articles of Incorporation is hereby
      amended to read

      (See attached Exhibit A)
<PAGE>   22



  5.   COMPLETE SECTION (a) IF THE AMENDMENT WAS ADOPTED BY THE UNANIMOUS
       CONSENT OF THE INCORPORATOR(S) BEFORE THE FIRST MEETING OF THE BOARD OF
       DIRECTORS OR TRUSTEES; OTHERWISE, COMPLETE SECTION (B)



  b.   [X]  The foregoing amendment to the Articles of Incorporation was
            duly adopted on the 28th day of  April   , 1994.  The
            amendment: (check one of the following)

       [X]  was duly adopted in accordance with Section 611(2) of the Act
            by the vote of the shareholders if a profit corporation, or by
            the vote of the shareholders or members if a nonprofit corporation,
            or by the vote of the directors if a nonprofit corporation 
            organized on a nonstock directorship basis.  The necessary votes
            were cast in favor of the amendment.


                                         Signed this 2nd  day of  May, 1994
                                                                 
                                     By /s/ Alfred R. Glancy III
                                       ----------------------------------------
                                         
                              Alfred R. Glancy III, Chairman, President and CEO
<PAGE>   23





                                   EXHIBIT A


       THIRD.  1. The total number of shares of all classes of stock which the
Corporation shall have authority to issue is 125,000,000 shares, which shall be
divided into two classes as follows:

        (a)     25,000,000 shares of Preferred Stock, no par value (Preferred 
                Stock); and

        (b)     100,000,000 shares of Common Stock of the par value of $.01 
                per share (Common Stock).

       2. The designations, voting powers, preferences and relative,
participating, optional or other special rights, and the qualifications,
limitations or restrictions of the above classes of stock and other general
provisions relating thereto shall be as follows:


                                     PART I
                                PREFERRED STOCK

       (a)     Shares of Preferred Stock may be issued in one or more series at
such time or times and for such consideration or considerations as the Board of
Directors may determine.  All shares of any one series shall be of equal rank
and identical in all respects expect that the dates from which dividends accrue
or accumulate with respect thereto may vary.

       (b)     The Board of Directors is expressly authorized at any time, and
from time to time, to provide for the issuance of shares of Preferred Stock in
one or more series, with such voting powers, full or limited, or without voting
powers, and such designations, preferences and relative, participating,
optional or other special rights and qualifications, limitations or
restrictions thereof, as shall be stated and expressed in the resolution or
resolutions providing for the issue thereof adopted by the Board of Directors,
and as are not stated and expressed in these Articles of Incorporation, or any
amendment thereto, including (but without limiting the generality of the
foregoing) the following:

       (i)     The distinctive designation and number of shares comprising such
               series, which number may (except where otherwise
               provided by the Board of Directors
<PAGE>   24


               in creating such series) be increased or decreased (but not
               below the number of shares then outstanding) from time to time
               by action of the Board of Directors.

       (ii)    The dividend rate or rates on the shares of such series and the
               relation which such dividends shall bear to the dividends
               payable on any other class of capital stock or on any other
               series of Preferred Stock, the terms and conditions upon which
               and the periods in respect of which dividends shall be payable,
               whether and upon what conditions such dividends shall be
               cumulative and, if cumulative, the date or dates from which 
               dividends shall accumulate.

      (iii)    Whether the shares of such series shall be redeemable, and, if
               redeemable, whether redeemable for cash, property or rights,
               including securities of any other corporation, at the option of
               either the holder or the Corporation or upon the happening of a
               specified event, the limitations and restrictions with respect
               to such redemption, the time or times when, the price or prices
               or rate or rates at which, the adjustments with which and the
               manner in which such shares shall be redeemable, including the
               manner of selecting shares of such series for redemption if less
               than all shares are to be redeemed.

        (iv)   The rights to which the holders of shares of such series shall
               be entitled, and the preferences, if any, over any other series
               (or of any other series over such series), upon the voluntary or
               involuntary liquidation, dissolution, distribution or winding up
               of the Corporation, which rights may vary depending on whether
               such liquidation, dissolution, distribution or winding up is
               voluntary or involuntary, and, if voluntary, may vary at
               different dates.

         (v)   Whether the shares of such series shall be subject to the
               operation of a purchase, retirement or sinking fund and, if so,
               whether and upon what conditions such purchase, retirement or
               sinking
<PAGE>   25


               fund shall be cumulative or noncumulative, the extent to which
               and the manner in which such fund shall be applied to the
               purchase or redemption of the shares of such series for
               retirement or to other corporate purposes and the terms and
               provisions relative to the operation thereof.

        (vi)   Whether the shares of such series shall be convertible into or
               exchangeable for shares of any other class or of any other
               series of any class of capital stock of the Corporation, and, if
               so convertible or exchangeable, the price or prices or the rate
               or rates of conversion or exchange and the method, if any, of
               adjusting the same, and any other terms and conditions of such
               conversion or exchange.

       (vii)   The voting powers, full and/or limited, if any, of the shares of
               such series, and whether and under what conditions the shares of
               such series (along or together with the shares of one or more
               other series having similar provisions) shall be entitled to
               vote separately as a single class, for the election of one or
               more additional directors of the Corporation in case of dividend
               arrearages, or other specified events, or upon other matters.

      (viii)   Whether the issuance of any additional shares of such series, or
               of any shares of any other series, shall be subject to
               restrictions as to issuance or as to the powers, preferences or
               rights of any such other series.

        (ix)   Any other preferences, privileges and powers and relative,
               participating, optional or other special rights, and
               qualifications, limitations or restrictions of such series, as
               the Board of Directors may deem advisable and as shall not be
               inconsistent with the provisions of these Articles of
               Incorporation.

        (c)  Unless the except to the extent otherwise required by law or
provided in the resolution or resolutions of the Board of Directors creating
any series of Preferred Stock pursuant to this Part I, the holders of the
shares of Preferred Stock shall have no

<PAGE>   26


voting power with respect to any matter whatsoever.  In no event shall the 
Preferred Stock be entitled to more than one vote in respect to each share
of Preferred Stock.

      (d)  Shares of Preferred Stock redeemed, converted, exchanged, purchased,
retired or surrendered to the Corporation, or which have been issued and
reacquired in any manner, may, upon compliance with any applicable provisions
of the Michigan Business Corporation Act, be given the status of authorized and
unissued shares of Preferred Stock and may be reissued by the Board of
Directors as part of the series of which they were originally a part or may be
reclassified into and reissued as part of a new series or as a part of any
other series, all subject to the protective conditions or restrictions of any
outstanding series of Preferred Stock.


                                    PART II
                                  COMMON STOCK

      (a)  Except as otherwise required by law or by any amendment to these
Articles of Incorporation, each holder of Common Stock shall have one vote for
each share of Common Stock held by such holder on all matters voted upon by the
shareholders.

      (b)  Subject to the preferential dividend rights, if any, applicable to
shares of Preferred Stock and subject to applicable requirements, if any, with
respect to the setting aside of sums of purchase, retirement or sinking funds
for Preferred Stock, the holders of Common Stock shall be entitled to receive,
to the extent permitted by law, such dividends as may be declared from time to
time by the Board of Directors.


                                    PART III
                               GENERAL PROVISIONS

      No holder of stock of any class of the Corporation shall be entitled as a
matter of right to purchase or subscribe for any part of any unissued stock of
any class, or of any additional stock of any class of capital stock of the
Corporation, or of any bonds, certificates of indebtedness, debentures, or
other securities, whether or not convertible into stock of the Corporation, now
or hereafter authorized, but any such stock or other securities may be issued
and disposed of pursuant to 

<PAGE>   27


resolution by the Board of Directors to such persons, firms, corporations or 
associations and upon such terms and for such consideration (not less
than the par value or stated value thereof) as the Board of Director in the
exercise of its discretion may determine and as may be permitted by law without
action by the shareholders.  The Board of Directors may provide for payment
therefor to be received by the Corporation in cash, personal property, real
property (or leases thereof) or services.  Any and all shares of stock so
issued for which the consideration so fixed has been paid or delivered, shall
be deemed fully paid and not liable to any further call or assessment.





     MICHIGAN DEPARTMENT OF COMMERCE - CORPORATION AND SECURITIES BUREAU

                                    FILED



<PAGE>   28



 MICHIGAN DEPARTMENT OF COMMERCE - CORPORATION AND SECURITIES AND SECURITIES
                                   BUREAU


Date Received


<TABLE>
<S><C>


                                                                      FILED
                                                                  APR 23, 1997

                                                                 Administrator
                                                  MI DEPARTMENT OF CONSUMER & INDUSTRY SERVICES
Name                                            CORPORATION, SECURITIES & LAND DEVELOPMENT BUREAU

Address

City                      State                    Zip Code



EFFECTIVE DATE:



        CERTIFICATE OF AMENDMENT TO THE ARTICLES OF INCORPORATION
                   FOR USE BY DOMESTIC PROFIT CORPORATIONS

         (Please read information and instructions on the last page)


            Pursuant to the provisions of Act 284, Public Acts of 1972 (profit corporations), or Act 162, Public Acts of 1982
                     (nonprofit corporations), the undersigned corporation executes the following Certificate:

1.       The present name of the corporation is:  MCN CORPORATION

2.       The identification number assigned by the Bureau is: 381-153

3.       The location of the registered office is:

         500 Griswold Street     Detroit,      Michigan                  48226   
         -------------------------------------------------------------------------------------- 
          (Street Address)            (City)                          (Zip Code)

4.       Article         I        of the Articles of Incorporation is hereby
                --------- --------
         amended to read as follows:

                 The name of the corporation shall be MCN Energy Group Inc.

                 The effective date of this Certificate of Amendment to the
                 Articles of Incorporation shall be April 28, 1997.
</TABLE>

<PAGE>   29



5.       COMPLETE SECTION (a) IF THE AMENDMENT WAS ADOPTED BY THE UNANIMOUS
         CONSENT OF THE INCORPORATOR(S) BEFORE THE FIRST MEETING OF THE BOARD
         OF DIRECTORS OR TRUSTEES; OTHERWISE, COMPLETE SECTION (B).  DO NOT
         COMPLETE BOTH.


b.       [ ]  The foregoing amendment to the Articles of Incorporation was duly
              adopted on the 22nd day of April, 1997.

         [ ]  was duly adopted in accordance with Section 611(2) of the Act
              by the vote of the shareholders if a profit corporation, or by
              the shareholders or members if a nonprofit corporation, or by
              the vote of the directors if a nonprofit corporation organized
              on a nonstock directorship basis.  The necessary votes were
              cast in favor of the amendment.





      Signed this 22nd day of April, 1997


      By        /s/ Daniel Schiffer
         ------   ------------------------------------------------------------- 
         (Only Signature of President, Vice-President, Chairperson, or Vice 
         Chairperson)

         Daniel Schiffer, Senior Vice President, General Counsel and Secretary 
         ---------------------------------------------------------------------
         (Type or Print Name)           (Type or Print Title)