Chemicals giant Ineos has completed its acquisition of the Forties Pipeline System in the North Sea from BP for $250m (£188m).
The 235-mile pipeline system links 85 North Sea oil and gas assets to the UK mainland and to the Ineos site in Grangemouth, delivering almost 40% of the UK's North Sea oil and gas production.
It has an average daily throughput of 445,000 barrels of oil and some 3,500 tonnes of natural gas.
The deal also includes the Kinneil gas processing plant and oil terminal, the Dalmeny storage facility and sites at Aberdeen.
The assets, along with 300 personnel, have been transferred to Ineos FPS, a newly-formed business that is a part of Ineos.
Ineos FPS chief executive Andrew Gardner described the acquisition of the Forties Pipeline as "significant and strategic".
"The acquisition reunites North Sea and Grangemouth assets under Ineos ownership," he said.
"Ineos is now the only UK company with refinery and petrochemical assets directly integrated into the North Sea and this deal provides the platform to potential future offshore Ineos investments."
The Forties pipeline was opened in 1975 to transport oil from BP's Forties field in the North Sea – the UK's first major offshore oilfield.
BP sold its interests in the Forties field to Apache in 2003 and sold its Grangemouth refinery and plants to Ineos in 2005.