Separately, NRG has also agreed to buy the 1,279MW Cottonwood natural gas-fired power station in the Entergy zone of east Texas from Kelson for $525m.

Both the acquisitions are expected to be funded with a combination of cash and other funding sources and to close by the year end.

NRG president and CEO David Crane said that the company sought for many years to fill the gap in its combined-cycle gas portfolio in the core markets, and with these acquisitions of ideally located assets, NRG is filling that gap in three of its four core regions.

The transactions are subject to closing of Blackstone’s merger with Dynegy and approvals from the Federal Energy Regulatory Commission and Department of Justice.