Oil prices hit a record peak close to $120 a barrel this morning as worker strikes in Nigeria and Britain shut down a big chunk of crude production, further tightening global supply.
US light crude rose 45 cents to $118.97 a barrel by late afternoon, after hitting a record high of $119.93.
London Brent crude was up 43 cents at $116.77 a barrel.
Crude prices have surged more than fivefold since 2002 and are up almost 25% since the start of the year as global supplies struggle to keep pace with rising demand in emerging economies, such as China.
A weak US dollar has also attracted investors into commodities markets, analysts have said.
Industrial action at the Grangemouth refinery, west of Edinburgh, has forced British energy giant BP to shut down the neighbouring Forties pipeline which supplies 40% of the country's oil and gas.
Around 1,200 workers are staging a two-day walkout, which began on Sunday, in a dispute over proposed changes to their pension rights. The strike has sparked panic buying of motor fuel in parts of Britain.
The Forties pipeline brings more than 700,000 barrels of crude oil ashore every day and supplies Britain and international markets. It cannot function without power and steam from Grangemouth.
