Public Service Enterprise Group (PEG)

This communication is not a solicitation of a proxy from any security holder of Exelon or PSEG. Exelon has filed with the Securities and Exchange Commission a Registration Statement on Form S-4 (Registration No. 333-122704) that contains the definitive joint proxy statement/prospectus that has been mailed by PSEG and Exelon to their respective security holders in connection with the proposed merger of Exelon and PSEG. WE URGE INVESTORS AND SECURITY HOLDERS TO READ THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT EXELON, PSEG AND THE PROPOSED MERGER. Investors and security holders are able to obtain these materials and other documents filed with the SEC free of charge at the SEC's website, http://www.sec.gov. In addition, a copy of the definitive joint proxy statement/prospectus may be obtained free of charge from Exelon Corporation, Shareholder Services, 10 South Dearborn Street, P.O. Box 805398, Chicago, Illinois 60680-5398, or from Public Service Enterprise Group Incorporated, Investor Relations, 80 Park Plaza, P.O. Box 1171, Newark, New Jersey 07101-1171.

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The definitive joint proxy statement/prospectus was mailed to shareholders on or around June 10, 2005. WE URGE INVESTORS AND SECURITY HOLDERS TO READ THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE PROPOSED TRANSACTION AND ANY OTHER RELEVANT DOCUMENTS, BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT EXELON, PSEG AND THE PROPOSED MERGER. Investors and security holders can obtain these materials and other documents filed with the SEC free of charge at the SEC's website, http://www.sec.gov. In addition, a copy of the definitive joint proxy statement/prospectus may be obtained free of charge from Exelon Corporation, Shareholder Services, 10 South Dearborn Street, P.O. Box 805398, Chicago, Illinois 60680-5398, or from Public Service Enterprise Group Incorporated, Investor Relations, 80 Park Plaza, P.O. Box 1171, Newark, New Jersey 07101-1171.

The respective directors and executive officers of Exelon and PSEG and other persons may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding Exelon’s and PSEG’s directors and executive officers and other participants in the solicitation and a description of their direct and indirect interests, by security holdings or otherwise, is available in the definitive joint proxy statement/prospectus.

The definitive joint proxy statement/prospectus was mailed to shareholders on or around June 10, 2005. WE URGE INVESTORS AND SECURITY HOLDERS TO READ THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS REGARDING THE PROPOSED TRANSACTION AND ANY OTHER RELEVANT DOCUMENTS, BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT EXELON, PSEG AND THE PROPOSED MERGER. Investors and security holders can obtain these materials and other documents filed with the SEC free of charge at the SEC's website, http://www.sec.gov. In addition, a copy of the definitive joint proxy statement/prospectus may be obtained free of charge from Exelon Corporation, Shareholder Services, 10 South Dearborn Street, P.O. Box 805398, Chicago, Illinois 60680-5398, or from Public Service Enterprise Group Incorporated, Investor Relations, 80 Park Plaza, P.O. Box 1171, Newark, New Jersey 07101-1171.

The respective directors and executive officers of Exelon and PSEG and other persons may be deemed to be participants in the solicitation of proxies in respect of the proposed transaction. Information regarding Exelon’s and PSEG’s directors and executive officers and other participants in the solicitation and a description of their direct and indirect interests, by security holdings or otherwise, is available in the definitive joint proxy statement/prospectus.

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This communication is not a solicitation of a proxy from any security holder of Public Service Enterprise Group Incorporated or Exelon Corporation. Exelon Corporation has filed with the Securities and Exchange Commission a registration statement (File No. 333-122704) that includes a preliminary joint proxy statement/prospectus. A definitive joint proxy statement/prospectus and other relevant documents are expected to be mailed by Public Service Enterprise Group Incorporated and Exelon Corporation to their respective security holders in connection with the proposed merger of Public Service Enterprise Group Incorporated and Exelon Corporation. WE URGE INVESTORS AND SECURITY HOLDERS TO READ THE DEFINITIVE JOINT PROXY STATEMENT/PROSPECTUS AND ANY OTHER RELEVANT DOCUMENTS WHEN THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT PUBLIC SERVICE ENTERPRISE GROUP INCORPORATED, EXELON CORPORATION AND THE PROPOSED MERGER. Investors and security holders will be able to obtain these materials (when they are available) and other documents filed with the Securities and Exchange Commission free of charge at the Securities and Exchange Commission's website, www.sec.gov. In addition, a copy of the definitive joint proxy statement/prospectus (when it becomes available) may be obtained free of charge from Public Service Enterprise Group Incorporated, Investor Relations, 80 Park Plaza, P.O. Box 1171, Newark, New Jersey 07101-1171, or from Exelon Corporation, Investor Relations, 10 South Dearborn Street, P.O. Box 805398, Chicago, Illinois 60680-5398.

This communication is not a solicitation of a proxy from any security holder of Public Service Enterprise Group Incorporated or Exelon Corporation. Exelon Corporation has filed with the Securities and Exchange Commission a registration statement (File No. 333-122704) that includes a preliminary joint proxy statement/prospectus. A definitive joint proxy statement/prospectus and other relevant documents are expected to be mailed by Public Service Enterprise Group Incorporated and Exelon Corporation to their respective security holders in connection with the proposed merger of Public Service Enterprise Group Incorporated and Exelon Corporation.