BG is boosting its presence in North America

The move comes as the British firm continues to build its presence in the North American gas market.

BG, which is buying the business from US pipeline operator El Paso, has targeted the liquefied natural gas market as a key area for growth.

"This acquisition secures valuable producing and exploration properties," the UK oil and gas company said.

In early trading on the London Stock Exchange, shares in BG fell on the news, down 3.75p at 272.25p.