Swiss petrochemicals giant INEOS has bought 12 oil and gas fields in the North Sea for £500 million.

The company, which operates the Grangemouth refinery and petrochemicals facility in Scotland, agreed to purchase it from Russian billionaire Mikhail Fridman’s investment fund LetterOne.

The deal comes as the UK Government had given Mr Fridman six months to dispose of the UK assets LetterOne had bought from German utility RWE earlier this year or have the licences revoked.

The 12 fields are said to provide up to 8% of the UK’s gas, enough to warm one in 10 homes.

INEOS Chairman Jim Ratcliffe said: “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 transaction is subject to competition clearance from the European Commission.

INEOS also owns a number of shale gas licences in England and Scotland and has pledged to invest $1 billion (£0.64bn) in the UK.