<PAGE>

                                                                   Exhibit 4-239

                               DTE ENERGY COMPANY
                                       AND
                           BNY MIDWEST TRUST COMPANY,
                                     TRUSTEE

                                   ----------

                             SUPPLEMENTAL INDENTURE
                            DATED AS OF MAY 15, 2006

                                   ----------

                SUPPLEMENTING THE AMENDED AND RESTATED INDENTURE
                            DATED AS OF APRIL 9, 2001

                                  PROVIDING FOR

                   2006 SERIES B 6.35 % SENIOR NOTES DUE 2016

<PAGE>

     SUPPLEMENTAL INDENTURE, dated as of the 15th day of May, 2006, between DTE
ENERGY COMPANY, a corporation organized and existing under the laws of the State
of Michigan (the "Company"), and BNY Midwest Trust Company an Illinois trust
company, having its principal office in Chicago, Illinois, as successor trustee
(the "Trustee");

     WHEREAS, the Company has heretofore executed and delivered to the Trustee
an Amended and Restated Indenture, dated as of April 9, 2001 (the "Original
Indenture"), as amended, supplemented or modified (as so amended, supplemented
or modified, the "Indenture") providing for the issuance by the Company from
time to time of its debt securities; and

     WHEREAS, the Company now desires to provide for the issuance of a series of
its unsecured, senior debt securities pursuant to the Original Indenture; and

     WHEREAS, the Company, in the exercise of the power and authority conferred
upon and reserved to it under the provisions of the Original Indenture,
including Section 901 thereof, and pursuant to appropriate resolutions of the
Board of Directors, has duly determined to make, execute and deliver to the
Trustee this Supplemental Indenture to the Original Indenture as permitted by
Section 201 and Section 301 of the Original Indenture in order to establish the
form or terms of, and to provide for the creation and issue of, a series of its
debt securities under the Original Indenture, which shall be known as the "2006
Series B 6.35% Senior Notes due 2016"; and

     WHEREAS, all things necessary to make such debt securities, when executed
by the Company and authenticated and delivered by the Trustee or any
Authenticating Agent and issued upon the terms and subject to the conditions
hereinafter and in the Original Indenture set forth against payment therefor,
the valid, binding and legal obligations of the Company and to make this
Supplemental Indenture a valid, binding and legal agreement of the Company, have
been done;

     NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH that, in order to
establish the terms of a series of debt securities, and for and in consideration
of the premises and of the covenants contained in the Original Indenture and in
this Supplemental Indenture and for other good and valuable consideration the
receipt and sufficiency of which are hereby acknowledged, it is mutually
covenanted and agreed as follows:

                                   ARTICLE ONE

                              DEFINITIONS AND OTHER
                        PROVISIONS OF GENERAL APPLICATION

     SECTION 101. Definitions. Each capitalized term that is used herein and is
defined in the Original Indenture shall have the meaning specified in the
Original Indenture unless such term is otherwise defined herein. The following
terms shall have the respective meanings set forth below:

     "Business Day" means any day other than a Saturday or Sunday or a day on
which commercial banks in The City of New York are required or authorized by law
or executive order to be closed.

<PAGE>

     SECTION 102. Section References. Each reference to a particular section set
forth in this Supplemental Indenture shall, unless the context otherwise
requires, refer to this Supplemental Indenture.

                                   ARTICLE TWO

                        TITLE AND TERMS OF THE SECURITIES

     SECTION 201. Title of the Securities; Stated Maturity. This Supplemental
Indenture hereby establishes a series of Securities, which shall be known as the
Company's "2006 Series B 6.35% Senior Notes due 2016" (the "Notes"). The Stated
Maturity on which the principal of the Notes shall be due and payable will be
June 1, 2016.

     SECTION 202. Rank. The Notes shall rank equally with all other unsecured
and unsubordinated indebtedness of the Company from time to time outstanding.

     SECTION 203. Variations from the Original Indenture. Section 1009 of the
Original Indenture shall be applicable to the Notes. Section 403(2) and Section
403(3) shall be applicable to the Notes; the Company's obligations under Section
1009, without limitation, shall be subject to defeasance in accordance with
Section 403(3).

     SECTION 204. Amount and Denominations; DTC. (a) The aggregate principal
amount of the Notes that may be issued under this Supplemental Indenture is
limited initially to $300,000,000 (except as provided in Section 301(2) of the
Original Indenture); provided that the Company may, without the consent of the
Holders of the Outstanding Notes, "reopen" the Notes so as to increase the
aggregate principal amount of the Notes Outstanding in compliance with the
procedures set forth in the Original Indenture, including Section 301 and
Section 303 thereof, so long as any such additional Notes have the same tenor
and terms (including, without limitation, rights to receive accrued and unpaid
interest) as the Notes then Outstanding. No additional Notes may be issued if an
Event of Default has occurred. The Notes shall be issuable only in fully
registered form and, as permitted by Section 301 and Section 302 of the Original
Indenture, in denominations of $1,000 and integral multiples thereof. The Notes
will initially be issued in global form (the "Global Notes") under a book-entry
system, registered in the name of The Depository Trust Company, as depository
("DTC"), or its nominee, which is hereby designated as "Depositary" under the
Indenture.

     (b) Further to Section 305 of the Original Indenture, any Global Note shall
be exchangeable for Notes registered in the name of, and a transfer of a Global
Note may be registered to, any Person other than the Depositary for such Note or
its nominee only if (i) such Depositary notifies the Company that it is
unwilling or unable to continue as Depositary for such Global Note or if at any
time such Depositary ceases to be a clearing agency registered under the
Exchange Act, and, in either such case, the Company does not appoint a successor
Depositary within 90 days thereafter, (ii) the Company executes and delivers to
the Trustee a Company Order that such Global Note shall be so exchangeable and
the transfer thereof so registrable or (iii) there shall have occurred and be
continuing an Event of Default or an event which, with the giving of notice or
lapse of time, or both, would constitute an Event of Default with respect to the
Notes. Upon the occurrence in respect of a Global Note of any or more of the
conditions


                                        2

<PAGE>

specified in clause (i), (ii) or (iii) of the preceding sentence, such Global
Note may be exchanged for Notes registered in the name of, and the transfer of
such Global Note may be registered to, such Persons (including Persons other
than the Depositary and its nominees) as such Depositary, in the case of an
exchange, and the Company, in the case of a transfer, shall direct.

     SECTION 205. Terms of the Notes.

     (a) The Notes shall bear interest at the rate of 6.35% per annum on the
principal amount thereof from May 26, 2006, or from the most recent Interest
Payment Date to which interest has been paid or duly provided for, until the
principal of the Notes becomes due and payable, and on any overdue principal and
premium and (to the extent that payment of such interest is enforceable under
applicable law) on any overdue installment of interest at the same rate per
annum during such overdue period. Interest on the Notes will be payable
semiannually in arrears on June 1 and December 1 of each year (each such date,
an "Interest Payment Date"), commencing December 1, 2006. The amount of interest
payable for any period shall be computed on the basis of twelve 30-day months
and a 360-day year.

     (b) In the event that any Interest Payment Date, redemption date or other
date of Maturity of the Notes is not a Business Day, then payment of the amount
payable on such date will be made on the next succeeding day which is a Business
Day (and without any interest or other payment in respect of any such delay), in
each case with the same force and effect as if made on such date. The interest
installment so payable, and punctually paid or duly provided for, on any
Interest Payment Date with respect to any Note will, as provided in the Original
Indenture, be paid to the person in whose name the Note (or one or more
Predecessor Securities, as defined in said Indenture) is registered at the close
of business on the relevant record date for such interest installment, which
shall be the fifteenth calendar day (whether or not a Business Day) prior to the
relevant Interest Payment Date (the "Regular Record Date"). Any such interest
installment not punctually paid or duly provided for shall forthwith cease to be
payable to the registered Holders on such Regular Record Date, and may either be
paid to the person in whose name the Note (or one or more Predecessor
Securities) is registered at the close of business on a Special Record Date to
be fixed by the Trustee for the payment of such defaulted interest, notice
whereof shall be given to the registered Holders of the Notes not less than ten
days prior to such Special Record Date, or may be paid at any time in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the Notes may be listed, and upon such notice as may be required by
such exchange, all as more fully provided in the Original Indenture. The
principal of, and premium, if any, and the interest on the Notes shall be
payable at the office or agency of the Company maintained for that purpose in
the Borough of Manhattan, The City of New York, in any coin or currency of the
United States of America which at the time of payment is legal tender for
payment of public and private debts; provided, however, that payment of interest
may be made at the option of the Company by check mailed to the registered
Holder at the close of business on the Regular Record Date at such address as
shall appear in the Security Register.

     (c) The Notes are not subject to repayment at the option of the Holders
thereof and are not subject to any sinking fund. As provided in the form of Note
attached hereto as Exhibit A, the Notes are subject to optional redemption, as a
whole or in part, by the Company prior to Stated Maturity of the principal
thereof on the terms set forth therein. Except as modified in the


                                        3

<PAGE>

form of the Note, redemption shall be effected in accordance with Article Eleven
of the Original Indenture.

     (d) The Notes shall have such other terms and provisions as are set forth
in the form of Note attached hereto as Exhibit A (which is incorporated by
reference in and made a part of this Supplemental Indenture as if set forth in
full at this place).

     SECTION 206. Form of Notes. Attached hereto as Exhibit A is the form of the
Notes.

                                  ARTICLE THREE

                            MISCELLANEOUS PROVISIONS

     The Trustee makes no undertaking or representations in respect of, and
shall not be responsible in any manner whatsoever for and in respect of, the
validity or sufficiency of this Supplemental Indenture or the proper
authorization 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 expressly amended hereby, the Original Indenture shall continue
in full force and effect in accordance with the provisions thereof and the
Original Indenture is in all respects hereby ratified and confirmed. This
Supplemental Indenture and all its provisions shall be deemed a part of the
Original Indenture in the manner and to the extent herein and therein provided.

     This Supplemental Indenture shall be governed by, and construed in
accordance with, the laws of the State of New York.

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


                                        4

<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed, all as of the day and year first above written.

                                        DTE ENERGY COMPANY


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


ATTEST:


By: /s/ Teresa M. Sebastian
    ---------------------------------
Name: Teresa M. Sebastian
Title: Assistant Corporate Secretary


                                        BNY MIDWEST TRUST COMPANY


                                        By: /s/ Roxane Ellwanger
                                            ------------------------------------
                                        Name: Roxane Ellwanger
                                        Title: Assistant Vice President


                                        5

<PAGE>

                                                                       EXHIBIT A

                                  FORM OF NOTE

THIS NOTE IS A GLOBAL NOTE WITHIN THE MEANING OF THE INDENTURE HEREINAFTER
REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A NOMINEE OF A
DEPOSITARY. UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR NOTES IN
CERTIFICATED FORM, THIS NOTE MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITORY TRUST COMPANY ("DTC"), TO A NOMINEE OF DTC OR BY DTC OR ANY SUCH
NOMINEE TO A SUCCESSOR OF DTC OR A NOMINEE OF SUCH SUCCESSOR. UNLESS THIS NOTE
IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF DTC TO THE ISSUER OR ITS AGENT
FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY NOTE ISSUED IS
REGISTERED IN THE NAME OF CEDE & CO., OR IN SUCH OTHER NAME AS REQUESTED BY AN
AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO.,
OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC),
ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY A PERSON IS
WRONGFUL, INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.

CUSIP NO.: 233331 AM 9                                              $300,000,000
NO. R---1

                               DTE ENERGY COMPANY
                    2006 SERIES B 6.35% SENIOR NOTES DUE 2016

     DTE ENERGY COMPANY, a corporation duly organized and existing under the
laws of the State of Michigan (herein referred to as the "Company", which term
includes any successor Person under the Indenture hereinafter referred to), for
value received, hereby promises to pay to CEDE & CO., or registered assigns, the
principal sum of $300,000,000 on June 1, 2016 ("Stated Maturity" with respect to
the principal of this Note), unless previously redeemed, and to pay interest at
the rate of 6.35% per annum on said principal sum from May 26 2006, or from the
most recent Interest Payment Date to which interest has been paid or duly
provided for, until the principal of this Note becomes due and payable, and on
any overdue principal and premium and (to the extent that payment of such
interest is enforceable under applicable law) on any overdue installment of
interest at the same rate per annum during such overdue period. Interest on this
Note will be payable semiannually in arrears on June 1 and December 1 of each
year (each such date, an "Interest Payment Date"), commencing December 1, 2006.
The amount of interest payable for any period shall be computed on the basis of
twelve 30-day months and a 360-day year.

     In the event that any Interest Payment Date, redemption date or other date
of Maturity of the Notes is not a Business Day, then payment of the amount
payable on such date will be made on the next succeeding day which is a Business
Day (and without any interest or other payment in respect of any such delay), in
each case with the same force and effect as if made on such date. A "Business
Day" means any day other than a Saturday or Sunday or a day on which


                                      A-1

<PAGE>

commercial banks in The City of New York are required or authorized by law or
executive order to be closed. The interest installment so payable, and
punctually paid or duly provided for, on any Interest Payment Date with respect
to this Note will, as provided in the Indenture, be paid to the person in whose
name this Note is registered at the close of business on the relevant record
date for such interest installment, which shall be the fifteenth calendar day
(whether or not a Business Day) prior to the relevant Interest Payment Date (the
"Regular Record Date"). Any such interest installment not punctually paid or
duly provided for shall forthwith cease to be payable to the registered Holders
on such Regular Record Date, and may either be paid to the person in whose name
this Note is registered at the close of business on a Special Record Date to be
fixed by the Trustee for the payment of such defaulted interest, notice whereof
shall be given to the registered Holders of the Notes not less than ten days
prior to such Special Record Date, or may be paid at any time in any other
lawful manner not inconsistent with the requirements of any securities exchange
on which the Notes may be listed, and upon such notice as may be required by
such exchange, all as more fully provided in the Indenture. The principal of,
and premium, if any, and the interest on the Notes shall be payable at the
office or agency of the Company maintained for that purpose in the Borough of
Manhattan, The City of New York, in any coin or currency of the United States of
America which at the time of payment is legal tender for payment of public and
private debts; provided, however, that payment of interest may be made at the
option of the Company by check mailed to the registered Holder at the close of
business on the Regular Record Date at such address as shall appear in the
Security Register. Notwithstanding anything else contained herein, if this Note
is a Global Note and is held in book-entry form through the facilities of the
Depositary, payments on this Note will be made to the Depositary or its nominee
in accordance with arrangements then in effect between the Trustee and the
Depositary.

     This Note is one of a duly authorized series of Securities of the Company,
designated as the "2006 Series B 6.35% Senior Notes due 2016" (the "Notes"),
initially limited to an aggregate principal amount of $300,000,000 (except for
Notes authenticated and delivered upon transfer of, or in exchange for, or in
lieu of other Notes, and except as further provided in the Indenture), all
issued or to be issued under and pursuant to an Amended and Restated Indenture,
dated as of April 9, 2001, as supplemented through and including the
Supplemental Indenture dated as of May 15, 2006 (together, as amended,
supplemented or modified, the "Indenture"), duly executed and delivered between
the Company and BNY Midwest Trust Company, an Illinois Corporation, as successor
trustee (herein referred to as the "Trustee", which term includes any successor
trustee under the Indenture), to which Indenture reference is hereby made for a
description of the respective rights, limitations of rights, obligations, duties
and immunities thereunder of the Trustee, the Company and the registered Holders
of the Notes and of the terms upon which the Notes are, and are to be,
authenticated and delivered.

     This Note is not subject to repayment at the option of the Holder hereof.
This Note is not subject to any sinking fund.

     This Note will be redeemable at the option of the Company, in whole at any
time or in part from time to time (any such date of optional redemption, an
"Optional Redemption Date," which shall be a "Redemption Date" for purposes of
the Indenture), at an optional redemption price (which shall be a "Redemption
Price" for purposes of the Indenture) equal to the greater of (i) 100% of the
principal amount of this Note to be redeemed and (ii) the sum of the present


                                      A-2

<PAGE>

values of the principal amount of this Note to be redeemed and the remaining
scheduled payments of interest on the principal amount of this Note to be
redeemed (exclusive of interest accrued to the related Optional Redemption Date)
until Stated Maturity, in each case discounted from their respective scheduled
payment dates to such Optional Redemption Date on a semiannual basis (assuming a
360-day year consisting of 30-day months) at the Adjusted Treasury Rate (as
defined below) plus 30 basis points, plus in either case, accrued interest
thereon to the date of redemption.

     Notwithstanding the foregoing, installments of interest on this Note that
are due and payable on Interest Payment Dates falling on or prior to a
Redemption Date will be payable on the Interest Payment Date to the registered
Holders as of the close of business on the relevant Record Date.

     "Adjusted Treasury Rate" means, with respect to any Optional Redemption
Date, the rate per annum equal to the semiannual equivalent yield to maturity of
the Comparable Treasury Issue, calculated on the third Business Day preceding
such Optional Redemption Date, using a price for the Comparable Treasury Issue
(expressed as a percentage of its principal amount) equal to the Comparable
Treasury Price for such Optional Redemption Date.

     "Comparable Treasury Issue" means the United States Treasury security
determined by the Reference Treasury Dealer as having a maturity comparable to
the remaining term of this Note that would be utilized, at the time of selection
and in accordance with customary financial practice, in pricing new issues of
corporate debt securities of comparable maturity with the remaining term of this
Note.

     "Comparable Treasury Price" means, with respect to any Optional Redemption
Date, (i) the average of the Reference Treasury Dealer Quotations for such
Optional Redemption Date, after excluding the highest and lowest such Reference
Treasury Dealer Quotations, or (ii) if the Trustee obtains fewer than three such
Reference Treasury Dealer Quotations, the average of all such quotations, or
(iii) if only one Reference Treasury Dealer Quotation is received, such
quotation.

     "Reference Treasury Dealer" means each of: (i) Barclays Capital Inc.,
Citigroup Global Markets Inc. and J.P. Morgan Securities Inc. (or their
respective affiliates which are Primary Treasury Dealers), and their respective
successors; provided, however, that if any of the foregoing cease to be a
primary U.S. Government securities dealer in the United States (a "Primary
Treasury Dealer"), the Company shall substitute therefor another Primary
Treasury Dealer; and (ii) any other Primary Treasury Dealer(s) selected by the
Trustee after consultation with the Company.

     "Reference Treasury Dealer Quotation" means, with respect to each Reference
Treasury Dealer and any Optional Redemption Date, the average, as determined by
the Trustee, of the bid and asked prices for the Comparable Treasury Issue
(expressed in each case as a percentage of its principal amount) quoted in
writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m., New York
City time, on the third Business Day preceding such Optional Redemption Date.


                                      A-3

<PAGE>

     Notice of any optional redemption will be mailed at least 30 days but not
more than 60 days before the Optional Redemption Date to the Holder hereof at
its registered address.

     Unless the Company defaults in payment of the applicable Redemption Price,
on and after the applicable Redemption Date interest will cease to accrue on the
principal amount of this Note called for redemption.

     If money sufficient to pay the applicable Redemption Price with respect to
the principal amount of and accrued interest on the principal amount of this
Note to be redeemed on the applicable Redemption Date is deposited with the
Trustee or Paying Agent on or before the related Redemption Date and certain
other conditions are satisfied, then on or after such Redemption Date, interest
will cease to accrue on the principal amount of this Note called for redemption.
If the Notes are only partially redeemed by the Company, the Trustee shall
select which Notes are to be redeemed by lot or in a manner it deems fair and
appropriate in accordance with the terms of the Indenture.

     In the event of redemption of this Note in part only, a new Note or Notes
for the unredeemed portion hereof will be issued in the name of the registered
Holder hereof upon the cancellation hereof.

     In case an Event of Default, as defined in the Indenture, shall have
occurred and be continuing, the principal hereof may be declared, and upon such
declaration shall become, due and payable, in the manner, with the effect and
subject to the conditions provided in the Indenture.

     The Indenture contains provisions for defeasance at any time of the entire
indebtedness of this Note upon compliance by the Company with certain conditions
set forth therein.

     The Indenture permits, with certain exceptions as therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Notes under the Indenture at any
time by the Company and the Trustee with the consent of the Holders of a
majority of the aggregate principal amount of all Notes issued under the
Indenture at the time outstanding and affected thereby; provided, however, that
no such amendment shall without the consent of the Holder of each Note so
affected, among other things (i) change the stated maturity of the principal of,
or any installment of principal of or interest on any Notes, or reduce the
principal amount thereof, or reduce the rate of interest thereon, or reduce any
premium payable upon the redemption thereof or (ii) reduce the percentage of
Notes, the Holders of which are required to consent to any amendment or waiver
or for certain other matters as set forth in the Indenture. The Indenture also
contains provisions permitting (i) the registered Holders of 66 2/3% in
aggregate principal amount of the Securities at the time outstanding affected
thereby, on behalf of the registered Holders of the Securities, to waive
compliance by the Company with certain provisions of the Indenture and (ii) the
registered Holders of not less than a majority in aggregate principal amount of
the Securities at the time outstanding affected thereby, on behalf of the
registered Holders of the Securities, to waive certain past defaults under the
Indenture and their consequences. Any such consent or waiver by the registered
Holder of this Note (unless revoked as provided in the Indenture) shall be
conclusive and binding upon such registered Holder and upon all future
registered Holders and


                                      A-4

<PAGE>

owners of this Note and of any Note issued in exchange hereof or in place hereof
(whether by registration of transfer or otherwise), irrespective of whether or
not any notation of such consent or waiver is made upon this Note.

     No reference herein to the Indenture and no provision of this Note or of
the Indenture shall alter or impair the obligation of the Company, which is
absolute and unconditional, to pay the principal of and premium, if any, and
interest on this Note at the time and place and at the rate and in the coin or
currency herein prescribed.

     As provided in the Indenture and subject to certain limitations therein set
forth, the transfer of this Note is registrable in the Security Register of the
Company, upon surrender of this Note for registration of transfer at the office
or agency of the Company in any place where the principal of and any interest on
this Note are payable or at such other offices or agencies as the Company may
designate, duly endorsed by or accompanied by a written instrument or
instruments of transfer in form satisfactory to the Company and the Security
Registrar or any transfer agent duly executed by the registered Holder hereof or
his or her attorney duly authorized in writing, and thereupon one or more new
Notes of this series and of like tenor, of authorized denominations and for the
same aggregate principal amount will be issued to the designated transferee or
transferees. No service charge will be made for any such transfer, but the
Company may require payment of a sum sufficient to cover any tax or other
governmental charge payable in relation thereto.

     Prior to due presentment for registration of transfer of this Note, the
Company, the Trustee, any paying agent and any Security Registrar may deem and
treat the registered Holder hereof as the absolute owner hereof (whether or not
this Note shall be overdue and notwithstanding any notice of ownership or
writing hereon made by anyone other than the Security Registrar) for the purpose
of receiving payment of or on account of the principal hereof and interest due
hereon and for all other purposes, and neither the Company nor the Trustee nor
any paying agent nor any Security Registrar shall be affected by any notice to
the contrary.

     The Notes are issuable only in fully registered form without coupons in
denominations of $1,000 and any integral multiple thereof. This Global Note is
exchangeable for Notes in definitive form only under certain limited
circumstances set forth in the Indenture. The Notes so issued are issuable only
in registered form without coupons in denominations of $1,000 and any integral
multiple thereof. As provided in the Indenture and subject to certain
limitations therein set forth, the Notes are exchangeable for a like aggregate
principal amount of the Notes of a different authorized denomination, as
requested by the registered Holder surrendering the same.

     As set forth in, and subject to the provisions of, the Indenture, no
registered owner of any Note will have any right to institute any proceeding
with respect to the Indenture or for any remedy thereunder, unless (i) such
registered owner shall have previously given to the Trustee written notice of a
continuing Event of Default with respect to the Notes, (ii) the registered
owners of not less than 25% in principal amount of the outstanding Notes shall
have made written request, and offered reasonable indemnity, to the Trustee to
institute such proceeding as trustee, (iii) the Trustee shall have failed to
institute such proceeding within 60 days and (iv) the Trustee shall not have
received from the registered owners of a majority in principal amount of the
outstanding Notes a direction inconsistent with such request within such 60-day
period;


                                      A-5

<PAGE>

provided, however, that such limitations do not apply to a suit instituted by
the registered owner hereof for the enforcement of payment of the principal of
or premium, if any, or any interest on this Note on or after the respective due
dates expressed herein.

     Unless the Certificate of Authentication hereon has been executed by the
Trustee or a duly appointed Authentication Agent referred to herein, this Note
shall not be entitled to any benefit under the Indenture or be valid or
obligatory for any purpose.

     The Indenture and this Note shall be governed by and construed in
accordance with the laws of the State of New York.

     All terms used in this Note which are defined in the Indenture shall have
the meanings assigned to them in the Indenture.


                                      A-6

<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Instrument to be duly
executed.

                                        DTE ENERGY COMPANY


                                        By:
                                            ------------------------------------
                                        Name:
                                              ----------------------------------
                                        Title:
                                               ---------------------------------

Date: May 26 2006


Attest:


By:
    ---------------------------------
Name:
      -------------------------------
Title:
       ------------------------------


                                      A-7

<PAGE>

                          CERTIFICATE OF AUTHENTICATION

     This is one of the Notes described in the within mentioned Indenture.

                                        BNY MIDWEST TRUST COMPANY
                                           as Trustee


                                        By
                                           -------------------------------------
                                           Authorized Signatory

Date: May 26, 2006


                                      A-8

<PAGE>

     FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and
transfer(s) unto

________________________________________________________________________________
     (Please insert Social Security or Other Identifying Number of Assignee)

________________________________________________________________________________
     (Please print or type name and address, including zip code of assignee)

the within Note and all rights thereunder, hereby irrevocably constituting and
appointing such person attorneys to transfer the within Note on the books of the
Issuer, with full power of substitution in the premises.

Dated: ________________________

NOTICE: The signature of this assignment must correspond with the name as
written upon the face of the within Note in every particular, without alteration
or enlargement or any change whatever and NOTICE: Signature(s) must be
guaranteed by a financial institution that is a member of the Securities
Transfer Agents Medallion Program ("STAMP"), the Stock Exchange, Inc. Medallion
Signature Program ("MSP"). When assignment is made by a guardian, trustee,
executor or administrator, an officer of a corporation, or anyone in a
representative capacity, proof of his or her authority to act must accompany
this Note.


                                      A-9