Calpine Corp. (CPN), a leading independent power producer and marketer, on Wednesday said it plans to sell all of its domestic oil and gas exploration and production assets for $1.05 billion.

Under terms of the sale, Calpine has formed a new subsidiary, Rosetta Resources Inc. (search) , that is selling 45.3 million shares for $725 million in private placement. Rosetta will use proceeds from the sale, plus $325 million in proceeds from a new credit facility, to buy all of Calpine's domestic oil and gas exploration and production assets.

The investor or investors acquiring the Rosetta shares were not named in Calpine's statement.

Once the deal is complete, Calpine will no longer own any interest in Rosetta, it said. The sale is scheduled to close on July 7.

Calpine shares rose 5 cents, or 1.4 percent, to $3.65 on the New York Stock Exchange (search).