BHP Billiton (NYSE: BHP) said it agreed to acquire all of Chesapeake Energy Corp. (NYSE: CHK)'s interests in the Fayetteville Shale play in central Arkansas for $4.75 billion, marking its entry into the US shale gas business.

The mining giant said on Monday the acquisition of this long-life field immediately adds over 10 trillion cubic feet of gas resources to its portfolio, adding that the operated position it is obtaining will immediately make the company a major North American shale gas producer.

Chesapeake's Fayetteville shale assets include around 487,000 acres of leasehold and producing natural gas properties located in Arkansas.

The assets bought generate strong margins and returns on capital at today's prices, BHP said.

BHP Billiton said the deal will raise its net reserve and resource base by 45 percent. These assets currently produce around 415 million cubic feet of natural gas equivalent per day and the deal includes midstream assets with about 420 miles of pipeline.

The transaction is expected to be completed in the first half of this year.

The Fayetteville Shale is a world-class onshore natural gas resource, said Michael Yeager, Chief Executive of BHP's Billiton Petroleum unit. This transaction...provides access to a competitive, long-life resource basin that benefits from our ability to invest through the economic cycles.

ADR's of BHP closed Friday's session at $92.39, while shares of CHK ended at $30.43.