French state-controlled power group Electricite de France SA (EDF.FR) owns 7.2% of U.S.-based Constellation Energy Group (CEG), the group noted Thursday after U.S. electricity company Exelon Corp. (EXC) announced it agreed to buy Constellation in a stock-for-stock deal valued at about $8 billion.

"EDF still owns 7.2% in Constellation and also owns 49.9% of its nuclear assets, through CENG, a joint-venture," a spokeswoman for the group said. She declined to further comment the Exelon announcement.

Chicago-based Exelon is one the country's largest electricity companies, delivering power to about 5.4 million customers in parts of
Illinois and Pennsylvania . It also owns and operates nuclear plants in the U.S.

Baltimore, Md.-based Constellation has power generation assets in several states including
Maryland , Pennsylvania , Alabama and Texas . The company will have to receive approval from state regulators in areas where Constellation operates.

The combined company will retain the Exelon name and be based in
Chicago . Following completion of the deal, Exelon shareholders will own about 78% of the combined company, while and Constellation shareholders will have about 22%.