...Exelon Generation Co. LLC (ExGen) is among the largest U.S. competitive generating companies, with approximately 32,500MW of owned or leased generating capacity, and is the nation's largest owner of nuclear generation. The company is a subsidiary of Exelon Corporation (EXC; BBB+/Stable). The company's operations include the generation, delivery and marketing of power across multiple geographic regions through its customer- facing Constellation Energy Group business. Constellation sells electricity and natural gas in competitive energy markets to both wholesale and retail customers, and is the nation's largest retail energy provider. The company's owned generating assets are concentrated in the Midwest and Mid-Atlantic regions of PJM Interconnection LLC....