Castleton Commodities International LLC agreed Friday to pay Anadarko Petroleum Corp. $1 billion-plus for upstream and midstream properties in the Carthage producing area of East Texas.

Once the acquisition is completed, the global commodities firm would own 160,000-plus net acres in East Texas and produce more than 320 MMcfe/d net from the region.

“The company is well-positioned to enhance the value of these acquired assets through further development of the Haynesville Shale, amongst other operational activities,” said Castleton Oil and Gas President Craig Jarchow. “We remain focused on strategically growing and diversifying our upstream and midstream assets, and broadening our portfolio with attractive opportunities that complement our long-term business strategy.”

Last year the firm acquiredsome East Texas operations from EDF Trading Resources LLC, including stakes in 545 wells and 30,855 net acres. Castleton’s extended Gulf Coast portfolio was built through multiple transactions, beginning with the acquisition of Patara Oil & Gas LLC’s East Texas assets in 2014, which gave it 650 gross wells on 16,000 net acres.

Most of the Gulf Coast portfolio is centered in the East Texas counties of Freestone, Upshur, Nacogdoches and Rusk. The assets are mostly operated and produce natural gas predominantly from the Cotton Valley and Bossier formations, which extend into the Haynesville Shale region.

Also in the U.S. onshore, Castleton owns and operates upstream and midstream assets in the Four Corners region of Utah and Colorado within the Paradox Basin, which includes more than 180 wells, 150,000 net acres and a 262-mile gas gathering system. In the Black Warrior Basin in Tuscaloosa County, AL, it operates more than 500 gas wells on 45,000 net acres with more than 300 miles of related gathering and transport lines.

The Stamford, CT-based firm has its hand in related energy endeavors as well. During 2Q2016, Castleton was ranked No. 14 on NGI‘s list of Top North American Gas Marketers with sales volumes of 2.71 Bcf/d — a 58% increase year/year. Two years ago it also said it would invest $1.2 billion to develop a methanol manufacturing plant in Plaquemines Parish, LA, but there have been no recent updates on the project, which was expected to begin this year.

Meanwhile, Anadarko has been paring its portfolio to concentrate more cash in the Permian and Denver-Julesburg basins and in the deepwater Gulf of Mexico. This year it reduced capital spending and its onshore rig count to wait out prices. Between July and September, Anadarko invested about $1 million across the play and ran no rigs in East Texas/North Louisiana.

In the region, the Woodlands, TX-based super independent holds an interest in the Carthage, Oak Hill, Henderson and Elm Grove areas, most of which is held by production across 360,000 gross acres. The Carthage field alone is estimated to have 70 years of legacy production.

Production across Anadarko’s East Texas/North Louisiana holdings totaled 47,000 boe/d during 3Q2016, with 209 MMcf/d of natural gas, 1,000 b/d of oil and 10,000 b/d of liquids. Output is down from 3Q2015, when the company produced a total of 53,000 boe/d, including 220 MMcf/d of gas, 2,000 b/d of oil and 15,000 b/d of liquids.

In the Haynesville Shale, Anadarko’s production now is tapped from from more than 100 wells, with about 500 identified locations across the leasehold. The acreage is 70% weighted to natural gas, with estimated ultimate recoveries of around 1 million boe/well.