Devon Energy Corp. agreed to buy closely held GeoSouthern Energy Corp.’s Eagle Ford assets for $6 billion in cash, expanding its shale holdings in one of the most prolific oil basins in the U.S.

The acquisition includes current production equivalent to 53,000 barrels a day and an estimated 400 million barrels of reserves, Oklahoma City-based Devon said today in a statement. The purchase from The Woodlands, Texas-based GeoSouthern covers 82,000 net acres of drilling leases in the Eagle Ford in Texas.

Devon, which has been criticized for not having enough high-growth U.S. oil projects with strong rates of return, has narrowed its focus to onshore North America and is seeking to boost oil production after selling assets in the Gulf of Mexico and Brazil in recent years. Output averaged the equivalent of about 691,000 barrels of oil a day in the third quarter, up 1.9 percent from the year-earlier period, the company said Nov. 6.

“Eagle Ford would certainly fulfill that if they’re in the right area,” James Sullivan, an analyst with Alembic Global Advisors in New York, said of Devon’s need for high-growth U.S. oil assets in a phone interview yesterday. Sullivan rates Devon the equivalent of a buy and doesn’t own the shares.

In February 2012, Blackstone Group LP and GeoSouthern closed on a $1 billion credit facility to help fund GeoSouthern’s drilling program in the Eagle Ford.

Production from the Eagle Ford may rise to as much as 1.645 million barrels of oil a day in 2022, nearly triple the output from 2012, according to a report from Dallas-based energy consultant Turner, Mason & Co.

Second Transaction

The GeoSouthern transaction marks the second major deal in a month for Devon. The company said Oct. 21 it and Crosstex Energy Inc. agreed to form a business that will acquire all of Crosstex’s shares and combine the two companies’ fuel pipeline and processing facilities.

The entity will consist of a master-limited partnership and a general partner, both publicly traded. Devon, which will control both of the entities and be the new company’s largest customer, has said it’s contributing assets valued at about $4.8 billion.

Devon held cash balances that totaled $4.3 billion as of Sept. 30. About $3.6 billion of its cash resides in units outside North America, Chief Financial Officer Jeff Agosta said on a Nov. 6 conference call with analysts and investors.