Chicago, IL, & Newark, NJ, Sept. 15, 2006 — Public Service Enterprise Group Incorporated (PSEG) and Exelon Corp. announced that Exelon has given PSEG formal notice of termination of the merger agreement announced December 20, 2004, and the companies have agreed to withdraw their application for merger approval, which has been pending before the New Jersey Board of Public Utilities (NJBPU) for more than 19 months.