Apache ( APA) plans to buy Anadarko Petroleum's ( APC) oil and gas interests in 28 West Texas fields for $1 billion.

The interests, located in the so-called Permian Basin, are anticipated to produce approximately 12,000 barrels of oil equivalent per day in 2007. Apache already has interests the Permian Basin that currently have daily production of 29,000 barrels of oil and 79 million cubic feet of gas per day.

"Acquiring control of these assets in the Permian is another step in evolving Apache's portfolio to facilitate continued growth," said Apache President and CEO G. Steven Farris in a press release.

Apache intends to facilitate the acquisition with debt, but said that upon completion of the deal its debt will still remain below 30% of its total capitalization.

For its part, Anadarko said the sale is part of a refocusing of its portfolio following its acquisitions of Kerr-McGee and Western Gas Resources in August.

"We are pleased with the value being realized through this transaction and will use the proceeds to further reduce leverage associated with the acquisitions," Anadarko Chairman, President and CEO Jim Hackett said.

On Wednesday, Anadarko announced an agreement to sell certain oil assets in the Northern Rockies to Encore Acquisition ( EAC) for $400 million.

The Permian Basin deal is expected to close by March 31.