UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549
                                    FORM 8-K



                                 CURRENT REPORT


                Pursuant to Section 13 or 15(d) of the Securities
                              Exchange Act of 1934


                                December 15, 2003
                                (Date of earliest
                                 event reported)





                                                                                 
 Commission File   Name of Registrant; State of Incorporation; Address of        IRS Employer
 Number            Principal Executive Offices; and Telephone Number             Identification Number
 ---------------   ----------------------------------------------------------    ------------------------
 1-16169           EXELON CORPORATION                                            23-2990190
                   (a Pennsylvania corporation)
                   10 South Dearborn Street - 37th Floor
                   P.O. Box 805379
                   Chicago, Illinois 60680-5379
                   (312) 394-7398





Item 5. Other Events On December 15, 2003 Exelon Corporation (Exelon), parent company of Exelon Thermal Technologies, announced that it has entered into an agreement to sell Exelon Thermal to Macquarie Bank Limited of Australia for $135 million before considering the tax impacts on the gain on the sale, transaction costs and the debt repayment. The transaction is expected to close during the first quarter of 2004 and will result in an after-tax gain of approximately $20 million. The sale does not impact operating earnings guidance for 2004 that has been previously disclosed. The estimated net cash proceeds will be approximately $75 million and will be used for general corporate purposes. The news release is attached to this report as Exhibit 99. Except for the historical information contained herein, certain of the matters discussed in this Report are forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of 1995, that are subject to risks and uncertainties. The factors that could cause actual results to differ materially from the forward-looking statements made by a registrant include those factors discussed herein, as well as the items discussed in (a) the Registrants' 2002 Annual Report on Form 10-K - ITEM 7. Management's Discussion and Analysis of Financial Condition and Results of Operations--Business Outlook and the Challenges in Managing Our Business for each of Exelon, ComEd, PECO and Generation, (b) the Registrants' 2002 Annual Report on Form 10-K - ITEM 8. Financial Statements and Supplementary Data: Exelon - Note 19, ComEd - Note 16, PECO - Note 18 and Generation - Note 13 and (c) other factors discussed in filings with the United States Securities and Exchange Commission (SEC) by the Registrants. Readers are cautioned not to place undue reliance on these forward-looking statements, which apply only as of the date of this Report. None of the Registrants undertakes any obligation to publicly release any revision to its forward-looking statements to reflect events or circumstances after the date of this Report.

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. EXELON CORPORATION /s/ Robert S. Shapard ---------------------------------------------------- Robert S. Shapard Executive Vice President and Chief Financial Officer Exelon Corporation December 18, 2003

                                                                     Exhibit 99

                                                                          EXELON
- --------------------------------------------------------------------------------
News Release

From:   Exelon Corporation                                For Immediate Release
        Corporate Communications                          ---------------------
        P.O. Box 805379                                   December 15, 2003
        Chicago, IL 60680-5379


Contact:   Kellie Szabo, 312.394.3071

  Exelon Corporation Announces Agreement to Sell Its Subsidiary, Exelon Thermal
              Technologies to Macquarie Bank Limited of Australia

CHICAGO (December 15, 2003) - Exelon Corporation, parent company of Exelon
Thermal Technologies, announced today that it has entered into an agreement to
sell Exelon Thermal to Macquarie Bank Limited of Australia for $135 million.
Exelon Thermal is an industry leader providing environmental-friendly cooling
solutions to facilities located in Chicago.

"This divestiture supports Exelon's corporate strategy to focus on our core
integrated utility businesses," said George Gilmore, Senior Vice President of
Exelon and President of Exelon Enterprises. "Exelon also believes this
transaction is in the best interest of Exelon Thermal. The buyer's knowledge of
the industry and enthusiasm for Exelon Thermal will provide the company with the
support needed to achieve its growth objectives."

The Chicago-based energy assets provide primarily chilled water to customers
from centralized plants, via underground piping, for cooling purposes. Customers
are typically office buildings that engage in long-term contracts for these
services.

The Macquarie group is a global leader in infrastructure acquisition, funding
and management, and manages about $10 billion of funds invested in
infrastructure assets and businesses around the world including toll roads,
airports, communications, water, rail and power assets. The Macquarie group has
been active in the United States for more than a decade and has over 200
employees in offices in Chicago, Houston, Los Angeles, Memphis, New York, San
Diego, San Jose and Seattle.

Advisors to Exelon on this transaction included Dresdner Kleinwort Wasserstein
and the law firm of Winston & Strawn. The agreement is subject to customary
closing conditions and approval from the City of Chicago. The transaction is
expected to close first quarter 2004.

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

Exelon  Corporation  is one of the  nation's  largest  electric  utilities  with
approximately 5 million  customers and more than $15 billion in annual revenues.
The  company  has  one of  the  industry's  largest  portfolios  of  electricity
generation capacity, with a nationwide reach and strong positions in the Midwest
and  Mid-Atlantic.  Exelon  distributes  electricity to  approximately 5 million
customers in Illinois and Pennsylvania and gas to more than 440,000 customers in
the Philadelphia area. Exelon is headquartered in Chicago and trades on the NYSE
under the ticker EXC.