<PAGE>


                                                                   EXHIBIT 99-18


                                 AMENDMENT NO. 4


                                                    Dated as of January 20, 2005


     This AMENDMENT among THE DETROIT EDISON COMPANY, a Michigan corporation
(the "Seller"), CAFCO, LLC (as successor to Corporate Asset Funding Company,
Inc.) (the "Investor"), CITIBANK, N.A. ("Citibank"), and CITICORP NORTH AMERICA,
INC., individually and as agent (the "Agent") for itself, the Owner and
Citibank.

     PRELIMINARY STATEMENTS:

         (a) The Seller, the Investor, Citibank and the Agent have entered into
a Trade Receivables Purchase and Sale Agreement, dated as of February 28, 1989,
an Amendment and Restatement thereof, dated as of October 1, 1991, an Amendment
and Restatement thereof dated as of March 9, 2001, an Amendment dated as of
January 17, 2003, an Amendment dated as of May 28, 2003 and an Amendment dated
as of February 25, 2004 (said Trade Receivables Purchase and Sale Agreement, as
so amended and restated, being the "Agreement"; the terms defined therein being
used herein as therein defined unless otherwise defined herein).

         (b) The Seller, the Investor, Citibank and the Agent have agreed to
amend the Agreement as hereinafter set forth.

     SECTION 1. Amendments to Agreement. Effective as of the date hereof, the
definition of "Facility Termination Date" in Section 1.01 of the Agreement is
amended by replacing the date therein with the date "January 19, 2006."

     SECTION 2. Representations and Warranties of the Seller. The Seller
represents and warrants as follows:

     (a) The Seller is a corporation duly incorporated, validly existing and in
good standing under the laws of the State of Michigan.

     (b) The execution, delivery and performance by the Seller of this Amendment
and the Agreement, as amended hereby, and the transactions contemplated hereby
and thereby are within the Seller's corporate powers, have been duly authorized
by all necessary corporate action, do not contravene (i) the Seller's charter or
by-laws or (ii) law or any contractual restriction binding on or affecting the
Seller and, except to the extent contemplated by the Agreement, do not result in
or require the creation of any lien, security interest or other charge or
encumbrance upon or with respect to any of its properties.

     (c) No authorization or approval or other action by, and no notice to or
filing with, any governmental authority or regulatory body is required for the
due execution, delivery and performance by the Seller of this Amendment or the
Agreement, as amended hereby, except for



<PAGE>


the filing from time to time of continuation statements continuing the
effectiveness of the UCC Financing Statements referred to in Article III of the
Agreement, which continuation statements have been duly filed and are in full
force and effect on the date hereof.

     (d) This Amendment and the Agreement, as amended hereby, constitute the
legal, valid and binding obligations of the Seller enforceable against the
Seller in accordance with their respective terms.

     SECTION 3. Reference to and Effect on the Agreement; Consent of the Agent.

         (a) On and after the date hereof, each reference in the Agreement to
"this Agreement", "hereunder", "hereof" or words of like import referring to the
Agreement, shall mean and be a reference to the Agreement as amended hereby.

         (b) Except as specifically amended above, the Agreement is and shall
continue to be in full force and effect and is hereby in all respects ratified
and confirmed.

         (c) The execution, delivery and effectiveness of this Amendment shall
not, except as expressly provided herein, operate as a waiver of any right,
power or remedy of the Seller, the Investor, the Owner, Citibank or the Agent
under the Agreement, nor constitute a waiver of any provision of the Agreement.

     SECTION 4. Costs, Expenses and Taxes. The Seller agrees to pay on demand
all costs and expenses in connection with the preparation, execution, delivery
and administration of this Amendment and the other documents to be delivered in
connection therewith, including, without limitation, the reasonable fees and
reasonable out-of-pocket expenses of counsel for the Agent with respect thereto
and with respect to advising the Agent as to its rights and responsibilities
hereunder and thereunder, and all costs and expenses, if any (including, without
limitation, reasonable counsel fees and reasonable expenses), in connection with
the enforcement (whether through negotiations, legal proceedings or otherwise)
of this Amendment and the other documents to be delivered in connection
therewith. In addition, the Seller shall pay any and all stamp and other taxes
payable or determined to be payable in connection with the execution and
delivery of this Amendment and the other documents to be delivered in connection
therewith, and agrees to indemnify the Agent, the Investor, the Owner, Citibank,
CNAI and their respective Affiliates against any and all liabilities with
respect to or resulting from any delay in paying or omission to pay such taxes.

     SECTION 5. Execution in Counterparts. This Amendment may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which when so executed and delivered shall be deemed to be an original
and all of which taken together shall constitute but one and the same agreement.
Delivery of an executed counterpart of a signature page to this Amendment by
telecopier shall be effective as delivery of a manually executed counterpart of
this Amendment.



<PAGE>


     SECTION 6. GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

     IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed by their respective officers thereunto duly authorized, as of the date
first above written.


                                      THE DETROIT EDISON COMPANY


                                      By:
                                         ---------------------------------------



                                      CAFCO, LLC
                                      By Citicorp North America, Inc.,
                                      as Attorney-in-Fact


                                      By:
                                         ---------------------------------------



                                      CITICORP NORTH AMERICA, INC.,
                                      Individually and as Agent


                                      By
                                         ---------------------------------------



                                      CITIBANK, N.A.


                                      By
                                         ---------------------------------------