The enterprise value of the transaction is £1.5bn ($2bn), with Centrica's equity investment amounting to approximately £200m for a 50% share.

Grain LNG comprises two National Grid subsidiaries which own and operate the U.K.’s largest liquefied natural gas import terminal under-long term contracts.

British Gas owner Centrica will jointly buy National Grid's Grain LNG terminal with U.S.-based infrastructure investor Energy Capital Partners (ECP), it said on Thursday, for an enterprise value of about 1.