Exelon

thumb|[[Chase Tower (Chicago)|Chase Tower, the location of the headquarters of Exelon]]

Exelon Corporation (NYSE: EXC) is an electricity generating and distributing company headquartered in the Chase Tower in the Chicago Loop area of Chicago. It was created in October, 2000 by the merger of PECO Energy Company and Unicom, of Philadelphia and Chicago respectively. Unicom owned Commonwealth Edison. Exelon has 5.2 million electricity customers and, in the Philadelphia suburbs, 460,000 natural gas customers.

In June, 2005 Exelon had full or majority ownership of 19 nuclear reactors in 11 nuclear power plants.

On June 30, 2005 the Federal Energy Regulatory Commission approved the merger of Exelon and Public Service Enterprise Group Inc., a New Jersey utility. Under this merger, Exelon would have become the largest utility in the United States. The two companies later broke off the agreement due to pressure put on the NJ Board of Public Utilities by public interest groups, including New Jersey Citizen Action. The merger sat pending in front of the NJBPU for nineteen months before Exelon concluded that they were fighting a losing battle.