Centrica said it will increase its stake in the Statfjord field in the North Sea, providing the owner of household energy supplier British Gas with a further source of gas supply.
The company said it had agreed to pay ConocoPhilips $223m (£142.3m) for its interests in the field, which straddles the UK and Norwegian North Sea.
The acquisition will leave Centrica with a 34 per cent stake in the field, and provide it with additional reserves of 36 m barrels of oil equivalent, Centrica said in a statement on Monday.
"This acquisition...underlines our commitment to invest in North Sea production and secure future energy supplies for the UK," said Managing Director Mark Hanafin.
Last year, Centrica announced a ten-year gas deal and asset buy from Statoil as it moved to shore up declining UK output and secure future energy supplies.