<PAGE>
                                                                     EXHIBIT 4-4


                          Executed in 75 Counterparts
                      of which this is Counterpart No. ___

================================================================================

                                 THIRTY-SEVENTH
                             SUPPLEMENTAL INDENTURE
                                       TO
                            INDENTURE OF MORTGAGE AND
                                  DEED OF TRUST
                            DATED AS OF MARCH 1, 1944

                                 AS RESTATED IN
                           PART II OF THE TWENTY-NINTH
                SUPPLEMENTAL INDENTURE DATED AS OF JULY 15, 1989
                     WHICH BECAME EFFECTIVE ON APRIL 1, 1994


                        MICHIGAN CONSOLIDATED GAS COMPANY
                                       TO
                                 CITIBANK, N.A.
                                     TRUSTEE
                          DATED AS OF FEBRUARY 15, 2003
                   CREATING AN ISSUE OF FIRST MORTGAGE BONDS,
                                  DESIGNATED AS
                         5.70% COLLATERAL BONDS DUE 2033

================================================================================
                  This instrument was drafted by and return to

                               FRANCES B. ROHLMAN
                             2000 2ND AVENUE, 688WCB
                                DETROIT, MI 48226
<PAGE>
                        MICHIGAN CONSOLIDATED GAS COMPANY

                      THIRTY-SEVENTH SUPPLEMENTAL INDENTURE
                          DATED AS OF FEBRUARY 15, 2003
                      SUPPLEMENTAL TO INDENTURE OF MORTGAGE
                                AND DEED OF TRUST
                            DATED AS OF MARCH 1, 1944

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                            PAGE
                                                                            ----
<S>                                                                         <C>
                                    ARTICLE I

ESTABLISHMENT OF AN ISSUE OF FIRST MORTGAGE BONDS, OF THE SERIES
DESIGNATED AND DISTINGUISHED AS "COLLATERAL BONDS" 5

    SECTION 1..........................................................        5
    SECTION 2..........................................................       12
    SECTION 3..........................................................       13
    SECTION 4..........................................................       13
    SECTION 5..........................................................       14

                                   ARTICLE II

ISSUE OF COLLATERAL BONDS..............................................       15

                                   ARTICLE III

THE TRUSTEE............................................................       15

                                   ARTICLE IV

MISCELLANEOUS PROVISIONS...............................................       15
</TABLE>


         THIS THIRTY- SEVENTH SUPPLEMENTAL INDENTURE, dated as of the 15th day
of February, 2003, between MICHIGAN CONSOLIDATED GAS COMPANY, a corporation duly
organized and existing under and by virtue of the laws of the State of Michigan
(hereinafter called the "Company"), having its principal place of business at
2000 2nd Avenue, Detroit, Michigan, and CITIBANK, N.A. (formerly First National
City Bank), a national banking association incorporated and existing under and
by virtue of the laws of the United States of America, having an office at 111
Wall Street in the Borough of Manhattan, The City of New York, New York,
successor to CITY BANK FARMERS TRUST COMPANY (hereinafter with its predecessors
as trustee called the "Mortgage Trustee" or the "Trustee"):


                                       2
<PAGE>
        WHEREAS, the Company has heretofore executed and delivered to the
Trustee an Indenture of Mortgage and Deed of Trust (the "Original Indenture"),
dated as of March 1, 1944;

         WHEREAS, the Company has heretofore executed and delivered to the
Trustee the Twenty-ninth Supplemental Indenture, which became effective April 1,
1994, to provide for the modification and restatement of the Original Indenture
as previously amended (as so amended, supplemented and modified the
"Indenture"), and to secure the Company's First Mortgage Bonds, unlimited in
aggregate principal amount except as therein otherwise provided, issued pursuant
to the:

      Thirtieth Supplemental Indenture, dated as of September 1, 1991;
      Thirty-first Supplemental Indenture, dated as of December 15, 1991;
      Thirty-second Supplemental Indenture, dated as of January 5, 1993;
      Thirty-third Supplemental Indenture, dated as of May 1, 1995;
      Thirty-fourth Supplemental Indenture, dated as of November 1, 1996;
      Thirty-fifth Supplemental Indenture, dated as of June 18, 1998; and
      Thirty-sixth Supplemental Indenture, dated as of August 15, 2001;

         WHEREAS, at the date hereof there were outstanding First Mortgage Bonds
of the Company issued under the Indenture, of 7 series in the principal amounts
set forth below (including Collateral Bonds):


                                       3
<PAGE>
<TABLE>
<CAPTION>
                                        AMOUNT              AMOUNT
    DESIGNATION OF SERIES          INITIALLY ISSUED       OUTSTANDING
    ---------------------          ----------------       -----------
<S>                                <C>                    <C>
First Mortgage Bonds
  (Secured Term Notes, Series A)
   7-1/2% Series due 2020             10,000,000            9,578,000
   6-3/4% Series due 2023             20,000,000           15,100,000

First Mortgage Bonds
  (Secured Term Notes, Series B)
  8-1/4% Series due 2014              80,000,000           80,000,000
  7-1/2% Series due 2020              20,000,000           18,833,000
  7% Series due 2025                  40,000,000           40,000,000

First Mortgage Bonds
  (Secured Term Notes, Series B)
  6.72% Series due 2003                4,150,000            4,150,000
  6.80% Series due 2003               15,850,000           15,850,000
  7.15% Series due 2006               40,000,000           40,000,000
  7.06% Series due 2012               40,000,000           40,000,000

First Mortgage Bonds
  (Secured Medium-Term Notes,
Series C)
  7.21% Series due 2007               30,000,000           30,000,000
  7.60% Series due 2017               15,000,000           14,604,000

Collateral Bonds
  (Remarketable Securities)

  Collateral Series A                 75,000,000           75,000,000
  Collateral Series B                 75,000,000           75,000,000

  (Senior Notes)
  Collateral Series C                 55,000,000           52,354,000
  Collateral Series D                 55,000,000           55,000,000
  6 1/8% Collateral                  200,000,000          200,000,000
  Bonds Due 2008


         and
</TABLE>

                                       4
<PAGE>
         WHEREAS, the Company desires in and by this Supplemental Indenture to
establish an issue of bonds to be issued under the Indenture of the series
established under the Thirty-fifth Supplemental Indenture, to designate the
terms thereof, to specify the particulars necessary to describe and define the
same and to specify such other provisions and agreements in respect thereof as
are in the Indenture provided or permitted; and

         WHEREAS, all the conditions and requirements necessary to make this
Supplemental Indenture, when duly executed and delivered, a valid, binding and
legal instrument in accordance with its terms and for the purposes herein
expressed, have been done, performed and fulfilled, and the execution and
delivery of this Supplemental Indenture in the form and with the terms hereof
have been in all respects duly authorized;

         NOW, THEREFORE, in consideration of the premises and in further
consideration of the sum of One Dollar in lawful money of the United States of
America paid to the Company by the Trustee at or before the execution and
delivery of this Thirty-seventh Supplemental Indenture, the receipt whereof is
hereby acknowledged, and of other good and valuable consideration, it is agreed
by and between the Company and the Trustee as follows:

                                    ARTICLE I
                          ESTABLISHMENT OF AN ISSUE OF
                       FIRST MORTGAGE BONDS, OF THE SERIES
               DESIGNATED AND DISTINGUISHED AS "COLLATERAL BONDS"

         SECTION 1 There is hereby established an issue of bonds to be issued
under and secured by the Indenture, to be known as "First Mortgage Bonds,"
designated and distinguished as "Collateral Bonds" of the Company (herein
collectively sometimes called the "Collateral Bonds") of the series established
under the Thirty-fifth Supplemental Indenture. The Collateral Bonds may be
issued without limitation as to aggregate principal amount except as provided in
the Indenture (including the Thirty-fifth Supplemental Indenture) and in this
Supplemental Indenture. The Collateral Bonds shall be registered bonds without
coupons and shall be dated as of the date of the authentication thereof by the
Mortgage Trustee.

         A separate issue of Collateral Bonds, designated "5.70% Collateral
Bonds due 2033," is being issued by the Company hereunder contemporaneously with
the issuance of a separate series of senior debt securities of the Company
designated as the Company's "5.70% Senior Notes, 2003 Series A due 2033" (the
"Senior Notes") and is being issued and assigned and delivered to Citibank,
N.A., as trustee (in such capacity, together with any


                                       5
<PAGE>
successor trustee(s), the "Senior Trustee") under the Indenture, dated as of
June 1, 1998, as amended, supplemented and modified, governing such senior debt
securities (as so amended, supplemented and modified, the "Senior Indenture"),
in such capacity, as collateral for the benefit of the holders of the Senior
Notes. The series of such senior debt securities collateralized by any
Collateral Bonds issued hereunder shall be referred to as the "Related Notes"
with respect to such Collateral Bonds.

         The issue of Collateral Bonds established hereby shall bear interest at
such rate or rates and be payable on such date or dates, shall mature and be
subject to mandatory or optional redemption on such date or dates and shall have
such other terms and provisions not inconsistent with the Indenture as are set
forth in the form of Collateral Bond, and the form of Trustee's Certificate to
be endorsed on such bonds, as are set forth substantially in the following forms
respectively (herein sometimes called the "Bond Form"):

No. R-1
Principal Amount

                                                                    $200,000,000

                        MICHIGAN CONSOLIDATED GAS COMPANY
              FIRST MORTGAGE BONDS, 5.70% COLLATERAL BONDS DUE 2033
                                being a series of
                              FIRST MORTGAGE BONDS

ORIGINAL ISSUE DATE: FEBRUARY 20, 2003

MATURITY DATE: MARCH 15, 2033

THE FIRST MORTGAGE BONDS, 5.70% COLLATERAL BONDS DUE 2033 (HEREINAFTER,
"COLLATERAL BONDS"), REPRESENTED BY THIS CERTIFICATE ARE BEING ISSUED AND
DELIVERED BY THE COMPANY TO CITIBANK, N.A., AS TRUSTEE (IN SUCH CAPACITY, THE
"SENIOR TRUSTEE") UNDER AN INDENTURE, DATED AS OF JUNE 1, 1998, BETWEEN THE
COMPANY AND THE SENIOR TRUSTEE, AS AMENDED, SUPPLEMENTED AND MODIFIED FROM TIME
TO TIME AND AS SUPPLEMENTED BY THE SUPPLEMENTAL INDENTURE THERETO DATED AS OF
FEBRUARY 15, 2003 (AS SO AMENDED, SUPPLEMENTED AND MODIFIED, THE "SENIOR
INDENTURE"). THE


                                       6
<PAGE>
COLLATERAL BONDS ARE TO BE HELD IN TRUST AS COLLATERAL FOR THE BENEFIT OF THE
HOLDERS OF $200,000,000 AGGREGATE PRINCIPAL AMOUNT OF 5.70% SENIOR NOTES, 2003
SERIES A DUE 2033 (THE "RELATED NOTES") ISSUED PURSUANT TO THE SENIOR INDENTURE.

THE COLLATERAL BONDS MAY NOT BE SOLD OR OTHERWISE TRANSFERRED (EXCEPT TO A
SUCCESSOR TRUSTEE UNDER THE SENIOR INDENTURE) UNTIL THE EARLIER OF THE RELEASE
DATE (AS DEFINED BELOW) OR THE PRIOR RETIREMENT OF THE RELATED NOTES THROUGH
REDEMPTION, REPURCHASE OR OTHERWISE.

THE INTEREST RATE ON THE COLLATERAL BONDS SHALL AT ALL TIMES BE IDENTICAL TO
THAT OF, AND SHALL BE ESTABLISHED IN THE MANNER SET FORTH IN, THE RELATED NOTES.

THE INTEREST PAYMENT DATES IN RESPECT OF THE COLLATERAL BONDS SHALL AT ALL TIMES
BE IDENTICAL TO THOSE OF, AND SHALL BE ESTABLISHED IN THE MANNER SET FORTH IN,
THE RELATED NOTES.

THE COMPANY SHALL MAKE PAYMENTS OF THE PRINCIPAL OF, AND PREMIUM, IF ANY, AND
INTEREST ON, THE COLLATERAL BONDS, TO THE SENIOR TRUSTEE, WHICH PAYMENTS SHALL
BE APPLIED BY THE SENIOR TRUSTEE TO THE SATISFACTION OF OBLIGATIONS ON THE
RELATED NOTES.

THE MATURITY DATE SPECIFIED ABOVE IS ALSO THE MATURITY DATE OF THE RELATED
NOTES.

         MICHIGAN CONSOLIDATED GAS COMPANY (hereinafter called the "Company"), a
corporation of the State of Michigan, for value received, hereby promises to pay
to CITIBANK, N.A., as trustee for the benefit of the holders of the Related
Notes, or registered assigns (in such capacity, the "Senior Trustee"), the sum
of Two Hundred Million Dollars ($200,000,000) on the Maturity Date specified
above, at the corporate trust office of the Mortgage Trustee hereinafter named
in the Borough of Manhattan, The City of New York, New York, or at the principal
office of any successor in trust, in lawful money of the United States of
America, and to pay interest thereon at the Interest Rate(s) from time to time
specified in or determined pursuant to the Related Notes, in like lawful money
payable at the office or agency of the Company in the Borough of Manhattan, The
City of New York, New York on such interest


                                       7
<PAGE>
payment date(s) and on the Maturity Date (each an "Interest Payment Date") as
provided in the Related Notes, from the Original Issue Date specified above or
from the most recent Interest Payment Date to which interest has been paid,
commencing on September 15, 2003, until the Company's obligation with respect to
the payment of such principal sum shall be discharged as provided in the
Indenture hereinafter mentioned and the Senior Indenture. If the date of the
Collateral Bonds represented by this certificate is after a Record Date (as
defined below) with respect to any Interest Payment Date and prior to such
Interest Payment Date, then payment of interest shall commence on the second
Interest Payment Date succeeding such date. If the Company shall default in the
payment of interest due on any Interest Payment Date, then interest shall be
payable from the next preceding Interest Payment Date to which interest has been
paid, or, if no such interest has been paid on the Collateral Bonds represented
by this certificate, from the Original Issue Date. So long as there is no
existing default in the payment of interest, the person in whose name the
Collateral Bonds represented by this certificate were registered at the close of
business on the relevant Record Date with respect to an Interest Payment Date
shall be entitled to receive the interest payable on such Interest Payment Date,
except that if the Company shall default in the payment of interest due on such
Interest Payment Date, such defaulted interest shall be paid to the person in
whose name the Collateral Bonds represented by this Certificate are registered
on the Record Date for the Interest Payment Date fixed by the Company for the
payment of such defaulted interest, provided that in no case shall such Record
Date be less than ten days after notice thereof shall have been mailed to all
registered holders of Collateral Bonds. The term "Record Date" as used herein
with respect to any Interest Payment Date otherwise shall mean the fifteenth
calendar (whether or not a Business Day) prior to such Interest Payment Date.

         "Business Day" means any day other than a day on which banking
institutions in The State of New York or the State of Michigan are authorized or
obligated pursuant to law or executive order to close. In the event that any
Interest Payment Date, redemption date or maturity date is not a Business Day,
then the required payment of principal, premium, if any, and interest will be
made on the next succeeding day that is a Business Day (and without any interest
or other payment in respect of any such delay).

         The bonds represented by this certificate, of the series hereinafter
specified, are bonds of the Company (herein called the "bonds") known as its
"First Mortgage Bonds," issued and to be issued in one or more series under, and
all equally and ratably secured by, an Indenture of Mortgage and Deed of Trust
dated as of March 1, 1944, duly executed by the Company to City Bank Farmers
Trust Company (now known as Citibank, N.A., successor trustee, as "Mortgage
Trustee") and Ralph E. Morton as restated in Part II of the Twenty-ninth


                                       8
<PAGE>
Supplemental Indenture dated as of July 15, 1989, which became effective on
April 1, 1994, to which indenture and all indentures supplemental thereto
executed on and after July 15, 1989 reference is hereby made for a description
of the property mortgaged and pledged, the nature and extent of the security,
the terms and conditions upon which the bonds are, and are to be, issued and
secured, and the rights of the holders of the bonds and of the Mortgage Trustee
in respect of such security (which indenture and all indentures supplemental
thereto, including the Thirty-seventh Supplemental Indenture dated as of
February 15, 2003, are hereinafter collectively called the "Original
Indenture"). As provided in the Original Indenture, the bonds may be for various
principal sums and are issuable in series, which may mature at different times,
may bear interest at different rates and may otherwise vary as therein provided.
The bonds represented by this certificate are part of a Series designated
"Collateral Bonds," herein called Collateral Bonds, created by the Thirty-fifth
Supplemental Indenture, dated as of June 18, 1998, as supplemented by the
Thirty-seventh Supplemental Indenture dated as of February 15, 2003, as provided
for in the Indenture.

         With the consent of the Company and to the extent permitted by and as
provided in the Indenture and the Senior Indenture, the rights and obligations
of the Company and/or the rights of the holders of the issue of Collateral Bonds
established by the Thirty-seventh Supplemental Indenture and/or the terms and
provisions of the Indenture may be modified or altered by such affirmative vote
or votes of the holders of the Related Notes then outstanding as are specified
in the Senior Indenture.

         The Collateral Bonds shall be redeemed if and to the extent Related
Notes are redeemed, as provided in the Senior Indenture with respect to the
Related Notes and in the Related Notes.

         In case an Event of Default as defined in the Indenture or the Senior
Indenture shall occur, the principal of the Collateral Bonds may become or be
declared due and payable in the manner, with the effect, and subject to the
conditions provided in the Indenture and the Senior Indenture.

         The Senior Trustee has agreed pursuant to the Senior Indenture to hold
the Collateral Bonds as collateral for the benefit of the holders of the Related
Notes under all circumstances and not to transfer (except to a successor
trustee) such Collateral Bonds until the earlier of the Release Date or the
prior retirement of the Related Notes through redemption, repurchase or
otherwise. "Release Date" means the date on which all First Mortgage Bonds of
the Company issued and outstanding under the Original Indenture, other than the
Collateral Bonds, have been retired (at, before or after the maturity thereof)
through payment,


                                       9
<PAGE>
redemption or otherwise provided that no default or event of default has
occurred and is continuing under the Senior Indenture. On the Release Date, the
Senior Trustee shall deliver to the Company for cancellation all Collateral
Bonds, and the Company shall cause the Senior Trustee to provide notice to all
holders of Related Notes of the occurrence of the Release Date. As a result, on
the Release Date, the Collateral Bonds shall cease to secure the Related Notes,
and, at the option of the Company, the Related Notes, either (i) will become
unsecured general obligations of the Company or (ii) will be secured by
substituted Collateral Bonds. Following the Release Date, the Company shall
cause the Indenture to be closed, and the Company shall not issue any additional
Collateral Bonds to be issued thereunder. From and after the Release Date, the
Company's obligations in respect of the Collateral Bonds shall be satisfied and
discharged.

         No recourse shall be had for the payment of the principal of, or the
interest on, the Collateral Bonds, or for any claim based hereon or otherwise in
respect of the Collateral Bonds or the Indenture, the Senior Indenture or any
indenture supplemental to either thereof, or against any incorporator,
stockholder, director or officer, past, present or future, of the Company, as
such, or any predecessor or successor corporation, either directly or through
the Company or any such predecessor or successor corporation, whether by virtue
of any constitution, statute or rule of law, or by the enforcement of any
assessment or penalty or otherwise, all such liability, whether at common law,
in equity, by any constitution, statute or otherwise, of incorporators,
stockholders, directors or officers being waived and released by the owner
hereof and every owner of any Related Note by the acceptance of the Collateral
Bonds or such Related Note, as the case may be, and as part of the consideration
for the issue thereof, and being likewise waived and released pursuant to the
Indenture and the Senior Indenture.

         This bond shall not be valid or become obligatory for any purpose
unless and until the certificate of authentication hereon shall have been
manually executed by the Mortgage Trustee or its successor in trust under the
Indenture.


                                       10
<PAGE>
         IN WITNESS WHEREOF, MICHIGAN CONSOLIDATED GAS COMPANY has caused this
certificate to be executed under its name with the signature of its duly
authorized Officer, under its corporate seal, which may be a facsimile, attested
with the signature of its Assistant Corporate Secretary.

  Dated:  February 20, 2003

                           MICHIGAN CONSOLIDATED GAS COMPANY


                           By:______________________________
                              N. A. Khouri
                              Vice President and Treasurer
Attest:

By:_____________________________________________
   Susan E. Riske, Assistant Corporate Secretary



         The bonds represented by this certificate constitute Collateral Bonds
of the series designated and described in the within-mentioned Indenture.

                           CITIBANK, N.A., as Mortgage Trustee


                           By:________________________________
                              Authorized Officer


                                       11
<PAGE>
         So long as there is no existing default in the payment of interest on
the Collateral Bonds, all Collateral Bonds authenticated by the Trustee after
the Record Date specified for any Interest Payment Date, and prior to such
Interest Payment Date (unless the issue date hereinafter specified is after such
Record Date) shall be dated the date of authentication, but shall bear interest
from such Interest Payment Date, and the person in whose name any Collateral
Bond is registered at the close of business on any Record Date with respect to
any Interest Payment Date shall be entitled to receive the interest payable on
such Interest Payment Date notwithstanding any transfer or exchange of such
Collateral Bond subsequent to the Record Date and on or prior to such Interest
Payment Date, except if and to the extent the Company shall default in the
payment of the interest due on such Interest Payment Date, in which case such
defaulted interest shall be paid to the person in whose name such Collateral
Bond is registered on the Record Date for the special Interest Payment Date
fixed by the Company for the payment of such defaulted interest, provided that
in no case shall such Record Date be less than ten days after notice thereof
shall have been mailed to all registered holders of Collateral Bonds; and
provided that interest payable on a maturity date shall be payable to the person
to whom the principal thereof is payable. If the issue date of any Collateral
Bond is after such Record Date, such Collateral Bond shall bear interest from
the issue date but payment of interest shall commence on the second Interest
Payment Date next succeeding the issue date. Any notice which is mailed as
herein provided shall be conclusively presumed to have been properly and
sufficiently given on the date of such mailing, whether or not the holder
receives notice.

         The terms "Interest Payment Date", "Record Date" and "Business Day" as
used herein are defined in the Bond Form.

         The term "issue date" as used herein with respect to the issue of
Collateral Bonds established hereby shall mean the date of first authentication
of such Collateral Bonds.

         As used in this Section 1, the term "default in the payment of
interest" means failure to pay interest on the applicable Interest Payment Date
disregarding any period of grace permitted by Section 9.01 of the Indenture.

         The Company shall make payments of the principal of, and premium or
interest on, the Collateral Bonds to the Senior Trustee, which payments shall be
applied by the Senior Trustee to satisfaction of obligations on the Related
Notes in respect of such Collateral Bonds.

         SECTION 2. The issue of Collateral Bonds established hereby shall be
redeemed if and to the extent the Related Notes with respect to such


                                       12
<PAGE>
Collateral Bonds are redeemed, as provided in the Senior Indenture and in such
Related Notes. The redemption price in respect of any Collateral Bonds
(including principal, premium, if any, and interest thereon) shall be the
redemption price applicable to the Related Notes with respect to such Collateral
Bonds. Any notice required to be furnished to the holders of the Collateral
Bonds or the Trustee relating to the redemption of such Collateral Bonds shall
be considered furnished by the delivery of appropriate notice to the holders of
the Related Notes or the Senior Trustee, as the case may be, as provided in the
Senior Indenture and the Related Notes with respect to such Collateral Bonds.
Any redemption payment made by the Company on the Related Notes (whether for
principal, premium, if any, or interest) shall be applied by the Senior Trustee
as payment of the redemption price in respect of the correspondingly redeemed
Collateral Bonds. In the event the Related Notes with respect to the issue of
Collateral Bonds established hereby are redeemed in part, an equivalent
aggregate principal amount of the issue of Collateral Bonds established hereby
shall be so redeemed, the Senior Trustee, as holder of the Collateral Bonds as
collateral for such Related Notes, shall deliver to the Mortgage Trustee for
cancellation an equivalent principal amount of the issue of Collateral Bonds
established hereby corresponding to the Related Notes so redeemed, and the
Company shall execute and the Mortgage Trustee shall authenticate and deliver,
without charge, to the Senior Trustee, as holder thereof, one or more new
Collateral Bonds of authorized denominations for the unredeemed balance of any
Collateral Bonds surrendered for redemption in connection with the redemption of
the Related Notes.

         SECTION 3. The Collateral Bonds shall be registered bonds without
coupons. The Mortgage Trustee shall be the registrar and paying agent for the
Collateral Bonds, which duties it hereby accepts. Collateral Bonds may be issued
in the denomination of $1,000 or any integral multiple thereof.

         SECTION 4. As further provided in the Bond Form, the Collateral Bonds
shall not be assignable or transferable except as may be set forth under Article
IV of the Senior Indenture, or, subject to compliance with applicable law, as
may be involved in the course of the exercise of rights and remedies consequent
upon an Event of Default under the Senior Indenture. Subject to the foregoing,
the Collateral Bonds shall be exchangeable upon surrender thereof at the
corporate trust office of the Trustee in the Borough of Manhattan, The City of
New York, New York, for registered bonds of the same aggregate principal amount
and other terms, but of different authorized denomination or denominations, such
exchanges to be made without service charge (except for any stamp tax or other
governmental charge).


                                       13
<PAGE>
         Every bond so surrendered shall be accompanied by a proper transfer
power duly executed by the registered owner or by duly authorized attorney
transferring such bond to the Company, and the signature to such transfer power
shall be guaranteed to the satisfaction of the Trustee. All bonds so surrendered
shall be forthwith canceled and delivered to or upon the order of the Company.
All bonds executed, authenticated and delivered in exchange for bonds so
surrendered shall be valid obligations of the Company, evidencing the same debt
as the bonds surrendered, and shall be secured by the same lien and be entitled
to the same benefits and protection as the bonds in exchange for which they are
executed, authenticated and delivered.

         The Company shall not be required to make any such exchange or any
registration of transfer (1) during a period of fifteen days next preceding any
Interest Payment Date, but only if there is an existing default in the payment
of interest on the Collateral Bonds on which such payment is due or (2) after
the bond so presented for exchange or registration of transfer, or any portion
thereof, has been called for redemption and notice thereof given to the
registered owner.

         SECTION 5. Pending the preparation of definitive Collateral Bonds, the
Company may from time to time execute, and upon its written order, the Trustee
shall authenticate and deliver, in lieu of such definitive bonds and subject to
the same provisions, limitations and conditions, one or more temporary bonds, in
registered form, of any denomination specified in the written order of the
Company for the authentication and delivery thereof, and with such omissions,
insertions and variations as may be determined by the Board of Directors of the
Company. Such temporary bonds shall be substantially of the tenor of the bonds
to be issued as herein before recited.

         If any such temporary Collateral Bonds shall at any time be so
authenticated and delivered in lieu of definitive bonds, the Company shall upon
request at its own expense prepare, execute and deliver to the Trustee and
thereupon, upon the presentation and surrender of temporary bonds, the Trustee
shall authenticate and deliver in exchange therefor, without charge to the
holder, definitive bonds of the same series and other terms, if any, and for the
same principal sum in the aggregate as the temporary bonds surrendered. All
temporary bonds so surrendered shall be forthwith canceled by the Trustee and
delivered to or upon the order of the Company. Until exchanged for definitive
bonds the temporary bonds shall in all respects be entitled to the lien and
security of the Indenture and all supplemental indentures.


                                       14
<PAGE>
                                   ARTICLE II
                            ISSUE OF COLLATERAL BONDS

         The Company hereby increases the principal amount of Collateral Bonds
of the Thirty-second Series issuable under the Indenture to $700,000,000, in
addition to the aggregate principal amount of Collateral Bonds previously
issued, subject to change from time to time as permitted by the provisions of
the Indenture, without the consent of the holders of the Collateral Bonds, and
subject further to the provisions of the Indenture with respect to exchanges and
replacements of bonds. Collateral Bonds in the aggregate principal amount of
$200,000,000 in respect of the Related Notes may be executed, authenticated and
delivered from time to time as permitted by the provisions of the Indenture,
including with respect to exchange and replacement of bonds. The Company further
may, without the consent of the holders of the Collateral Bonds, "reopen" the
issue of Collateral Bonds established hereby so as to increase the aggregate
principal amount of such Collateral Bonds outstanding under the Indenture in
compliance with the procedures set forth in the Indenture, to equal the
aggregate principal amount of Related Notes outstanding upon a "reopening" of
such series, so long as any such additional Collateral Bonds have the same tenor
and terms as the issue of Collateral Bonds established hereby.

                                   ARTICLE III
                                   THE TRUSTEE

         The Trustee shall not be responsible in any manner whatsoever for or in
respect of the validity or sufficiency of this Supplemental Indenture or the due
execution hereof by the Company, or for or in respect of the recitals and
statements contained herein, all of which recitals and statements are made
solely by the Company.

         Except as herein otherwise provided, no duties, responsibilities or
liabilities are assumed, or shall be construed to be assumed, by the Trustee by
reason of this Supplemental Indenture other than as set forth in the Indenture
and this Supplemental Indenture is executed and accepted on behalf of the
Trustee, subject to all the terms and conditions set forth in the Indenture, as
fully to all intents as if the same were herein set forth at length.

                                   ARTICLE IV
                            MISCELLANEOUS PROVISIONS

         Except insofar as herein otherwise expressly provided, all the
provisions, terms and conditions of the Indenture shall be deemed to be
incorporated in, and made a part of, this Thirty-seventh Supplemental Indenture


                                       15
<PAGE>
and the Twenty-ninth Supplemental Indenture dated as of July 15, 1989, by the
Thirtieth Supplemental Indenture dated as of September 1, 1991, by the
Thirty-first Supplemental Indenture dated as of December 15, 1991, by the
Thirty-second Supplemental Indenture dated as of January 5, 1993, by the
Thirty-third Supplemental Indenture dated as of May 1, 1995, by the
Thirty-fourth Supplemental Indenture dated as of November 1, 1996, by the
Thirty-fifth Supplemental Indenture dated as of June 18, 1998, by the
Thirty-sixth Supplemental Indenture dated as of August 15, 2001 and by this
Supplemental Indenture is in all respects ratified and confirmed; and the
Indenture and said Supplemental Indentures shall be read, taken and construed as
one and the same instrument.

         Except to the extent specifically provided therein, no provision of
this Supplemental Indenture or any future supplemental indenture is intended to
modify, and the parties do hereby adopt and confirm, the provisions of Section
318(c) of the Trust Indenture Act, which amend and supersede provisions of the
Indenture in effect prior to November 15, 1990.

         Nothing in this Supplemental Indenture is intended, or shall be
construed, to give to any person or corporation, other than the parties hereto
and the holders of Collateral Bonds issued and to be issued under and secured by
the Indenture, any legal or equitable right, remedy or claim under or in respect
of this Supplemental Indenture, or under any covenant, condition or provision
herein contained, all the covenants, conditions and provisions of this
Supplemental Indenture being intended to be, and being, for the sole and
exclusive benefit of the parties hereto and of the holders of bonds issued and
to be issued under the Indenture and secured thereby.

         All covenants, promises and agreements in this Supplemental Indenture
contained by or on behalf of the Company shall bind its successors and assigns
whether so expressed or not.

         This Supplemental Indenture may be executed in any number of
counterparts, and each of such counterparts when so executed shall be deemed to
be an original; but all such counterparts shall together constitute but one and
the same instrument.


                                       16
<PAGE>
         IN WITNESS WHEREOF, MICHIGAN CONSOLIDATED GAS COMPANY has caused this
Supplemental Indenture to be executed by its duly authorized Officer, and its
corporate seal to be hereunto affixed, and Citibank, N.A., as Mortgage Trustee
as aforesaid, has caused the same to be executed by one of its authorized
signatories and its corporate seal to be hereunto affixed, on the respective
dates of their acknowledgments hereinafter set forth, as of the date and year
first above written.

MICHIGAN CONSOLIDATED GAS COMPANY

By:  /s/ N. A. Khouri
     Name: N. A. Khouri
     Title: Vice President and Treasurer

Signed, sealed, acknowledged and delivered by MICHIGAN CONSOLIDATED GAS COMPANY
in the presence of:

/s/ K. Hier
K. Hier

/s/ F. Ginste
F. Ginste
<PAGE>
State of Michigan }
                  } ss.
County of Wayne   }


         The foregoing instrument was acknowledged before me this 15th day of
February, 2003, by N. A. Khouri, of MICHIGAN CONSOLIDATED GAS COMPANY, a
Michigan corporation, on behalf of the corporation.

/s/Andrea L. Campau                                /s/Deborah Dub
ANDREA L. CAMPAU                                   DEBORAH DUB
Notary Public, Wayne County, MI                    Notary Public, Oakland
                                                     County, MI
My Commission Expires                              My Commission Expires
May 10, 2005                                       11-02-2005

Citibank, N.A., as Mortgage Trustee,
By:/s/Wafaa Orfy
      Name: Wafaa Orfy
      Title: Vice President

Signed, sealed, acknowledged and
delivered by CITIBANK, N.A.
in the presence of:

/s/John J. Byrnes
John J. Byrnes

/s/Nancy Forte
Nancy Forte


                                       2
<PAGE>
State of New York          }
                           } ss.
County of New York         }

         The foregoing instrument was acknowledged before me this 13th day of
February, 2003, by Wafaa Orfy, as Vice President of Citibank, N.A., a national
banking association, on behalf of the association, as Trustee, as in said
instrument described.

                           /s/Jeffry Berger

                           JEFFRY BERGER
                           Notary Public, State of New York
                           No. 01BE5015814
                           Qualified in Kings County
                           Commission Expires July 26, 2005


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