Ineos is to acquire the Forties Pipeline System in the North Sea from BP for almost £200 million.
The pipeline transports on average around 450,000 barrels of oil per day - about 40 per cent of UK production.
It is one of the oldest in the sector, having started operating in the Forties field in 1975.
The system links 85 North Sea Oil and Gas assets to the UK mainland, and to the Ineos site in Grangemouth.
When the deal is completed, the ownership and operation of of the pipeline, the Kinneil terminal and gas processing plant, the Dalmeny terminal, sites at Aberdeen, the Forties Unity Platform and associated infrastructure will transfer to Ineos.
Around 300 people that operate and support the FPS business at Kinneil, Grangemouth, Dalmeny and offshore will become part of the INEOS Upstream business.
Twenty per cent of the oil that passes down the pipeline feeds the Ineos refinery to provide 80 per cent of Scotland’s fuel.
Ineos boss Jim Ratcliffe said: “The North Sea continues to present new opportunities for Ineos. The Forties Pipeline System is a UK strategic asset and was originally designed to work together to feed the Grangemouth refinery and petrochemical facilities.
“We have a strong track record of acquiring non-core assets and improving their efficiency and reliability, securing long term employment and investment. I am delighted that we can now bring this integrated system back under single ownership in Ineos.”
Bob Dudlen, BP group chief executive, said: “The pipeline has long been an important feedstock supplier to Ineos at Grangemouth. We believe that through also owning FPS, Ineos will be able produce greater efficiencies and help secure a competitive long-term future for this important piece of UK oil and gas infrastructure.”
Under the terms of the deal Ineos will pay BP a cash payment of $125 million on completion and an earn-out arrangement over seven years that could total another $125 million.