Commonwealth Edison Co. completed the sale of $800 million of its 4% series 124 first mortgage bonds due March 1, 2048.

The Exelon Corp. subsidiary plans to use the proceeds to refinance $700 million of its 5.80% first mortgage bonds due March 15, to repay a portion of its outstanding commercial paper obligations and for other general corporate purposes, according to a Feb. 20 Form 8-K filing.

Barclays Capital Inc., Merrill Lynch Pierce Fenner & Smith Inc., Scotia Capital (USA) Inc., Morgan Stanley & Co. LLC, RBC Capital Markets LLC and TD Securities (USA) LLC acted as joint book-running managers.