Anadarko Petroleum Corp., has sold its Marcellus Shale operations in north-central Pennsylvania to a subsidiary of Alta Resources Development LLC for $1.24 billion, marking the exit of one of the larger shale gas developers in state forests.

The company's assets include drilling rights in the Loyalsock State Forest in Lycoming County, where Anadarko's controversial extraction plans have been blocked by legal and administrative obstacles.

Anadarko, which is based in The Woodlands, Texas, said its Marcellus Shale divestiture includes about 195,000 net acres, which produced about 470 million cubic feet of gas per day. The oil and gas company, which has international operations, has announced $5 billion in asset sales this year.

The sale to Alta Resources represents the return of a company that explored the Marcellus in Susquehanna County from 2008 to 2010, before divesting its holdings. The late George P. Mitchell, who was widely regarded as the father of shale gas for his development of hydraulic fracturing techniques, was an early partner in Alta.

The transaction is expected to close during the first quarter of 2017. Anadarko's regional headquarters are in Williamsport.