The Constellation Energy Group trades, distributes, and supplies energy to Maryland, and other states. Constellation Energy Commodities Group is the companies energy trading subsidiary and performs as one of the top energy marketers in North America.

Between September 15 and 16, 2008, Constellation stocks lost over 50% of their value, closing at $17.23 per share. The rout came in the wake of the bankruptcy filing of Lehman Brothers, the major financial services firm with which Constellation has an energy trading relationship.Baltimore Sun: Constellation Energy shares drop 36 percent (September 16, 2008)

On September 18, 2008, it was announced the Constellation would be acquired by Warren Buffett's MidAmerican Energy for $4.7 billion.BaltimoreSun.com: CEG to be Sold to MidAmerican (September 18, 2008)

The Constellation Generation subsidiary boasts more that 8,700 megawatts of generating capacity, allowing Constellation to supple energy to 11 states through its Constellation NewEnergy subsidiary. In 2007, Constellation NewEnergy acquired Cornerstone Energy, making it one of the largest natural gas marketing companies in the United States.

1. 1816: Gas Light Company of Baltimore was founded
2. 1950: Constellation Energy went public
3. 2005: Acquired by FPL Group, Inc.
4. 2008: Bought by MidAmerican Energy