Southwestern Energy Co. is increasing its hold on Lower 48 natural gas with a $1.85 billion takeover of GEP Haynesville LLC, the third-largest private explorer in the play.

The transaction, once completed, would boost Southwestern’s Haynesville scale by 700 MMcf/d, giving it total estimated output of 4.7 Bcfe/d. The deal, it said, “expands exposure” to the Gulf Coast, where demand is surging for liquefied natural gas (LNG) exports.

“This strategic move positions Southwestern as the largest producer in the Haynesville and enhances our leading presence in the top two premier natural gas basins in the U.S.,” CEO Bill Way said. “The company’s increased scale, from both a reserves and production perspective, is expected to deliver higher margins, enhanced economic...