Jim Ratcliffe’s Ineos group has made its first investment in the North Sea in buying 12 gasfields from L1 Energy.

The billionaire is thought to have paid around £500m for the assets owned by Ukrainian billionaire Mikhail Fridman.

Mr Ratcliffe is investing £300m at Ineos’s Grangemouth refinery after winning a stand-off with the trade unions over pay and pensions two years ago.

He said Ineos had “moved fast to acquire these high quality, low risk assets” in the Southern North Sea which provide up to eight per cent of the UK’s gas.

He went on: “Ineos has been very open about its intention to make strategic investments in the North Sea and this acquisition is our first step in fulfilling this goal. It will also help our UK petrochemical assets to have ongoing access to competitive energy”. The largely unmanned platforms, infrastructure and support team will form part of a new upstream division based in London.