U.S. nuclear power provider Constellation Energy on Friday agreed to buy privately held natural gas and geothermal company Calpine Corp for $16.4 billion, one of the biggest acquisitions in U.S. power industry history.

Constellation Energy Corporation ( CEG, Financials) said Friday that it will purchase Calpine Corporation ( CPN, Financials) for $26.6 billion in cash and shares, becoming the largest US renewable energy provider. The agreement combines Calpine's low-carbon natural gas and geothermal with Constellation's emissions-free nuclear.

Constellation is buying power natural gas and geothermal power provider Calpine in a cash-and-stock deal valued at approximately $16.4 billion, joining together two of the country’s biggest power companies.

US energy giant Constellation Energy has agreed to acquire Calpine Corporation, an independent power producer, for $26.6 billion, including debt considerations. The transaction includes 50 million shares of Constellation stock, $4.5 billion in cash, and the assumption of about $12.7 billion in Calpine’s net debt.

Constellation Energy is nearing a roughly $30 billion deal to acquire power producer Calpine, people familiar with the matter said on Wednesday, a move that would significantly expand Constellation's generation assets at a time of rising U.

Constellation Energy Corp. (CEG) stock gained over 3% in morning trade on Tuesday after multiple analysts raised their price targets in response to the company's acquisition of Calpine. The transaction,

Constellation Energy Corporation CEG and Calpine Corp. announced that they have entered into a definitive agreement under which CEG will acquire Calpine in a cash and stock transaction valued at an equity purchase price of nearly $16.