NRG Energy (NRG) said Monday that it has agreed to acquire a portfolio of natural gas generation facilities and CPower, a commercial and industrial virtual power plant platform, from LS Power Equity Advisors in a cash and common stock transaction.

The transaction has an enterprise value of $12 billion, including debt, NRG said.

The transaction value consists of $6.4 billion in cash, $2.8 billion of NRG stock, and $3.2 billion of net debt assumed at closing, less $0.4 billion of the net present value of tax benefits generated directly as a result of the transaction, NRG said. The acquisition is expected to close in Q1 next year.

The acquisition will add 18 natural-gas fired facilities with a total capacity of around 13 gigawatts, doubling NRG's generation capacity to 25 gigawatts, NRG said.

The acquisition is expected to be immediately accretive to NRG's adjusted earnings per share, the company said.