X0304 4 2012-03-12 1 0001004440 CONSTELLATION ENERGY GROUP INC CEG 0001164638 LAWLESS ROBERT J 100 CONSTELLATION WAY BALTIMORE MD 21202 1 0 0 0 Common Stock 2012-03-12 4 D 0 3520 D 0 D Phantom Stock 2012-03-12 4 D 0 36021.8502 D Common Stock 36021.8502 0 D Disposition of common stock pursuant to Agreement and Plan of Merger (the "Merger") between Exelon Corporation ("Exelon"), Bolt Acquisition Corporation, and Constellation Energy Group, Inc. ("Constellation"), whereby each share of Constellation common stock, without par value, converted into the right to receive 0.9300 shares of Exelon common stock, without par value, having a closing market value of $39.81 per share on the effective date of the Merger and a cash payment being made for any fractional shares. Disposition of phantom stock (which is in the form of a deferred stock unit) pursuant to the Merger, whereby each unit of Constellation phantom stock was converted into 0.9300 units of Exelon phantom stock, which will settle in cash upon the termination of the reporting person's service on the Exelon Board of Directors. Sean J. Klein, Attorney-In-Fact 2012-03-14