Exelon, the Chicago electric power giant which owns Philadelphia's Peco Energy and the largest group of U.S. nuclear plants, says it has agreed to pay $6.8 billion, or $27.25 a share, cash, for Pepco, which owns Delmarva Power in Delaware and Atlantic Electric in South Jersey. Exelon statement here, AP here, Bloomberg here.  

In its statement, Exelon said the deal would make it the dominant mid-Atlantic utility. It also said it will keep the newly acquired companies' HQ offices and charitable commitments going.