Oil prices hit an all-time high near $120 a barrel Monday after a weekend refinery strike closed a pipeline system that delivers a third of Britain's North Sea oil to refineries in the UK. The shutdown comes amid supply outages in Nigeria that have helped to support oil against a strengthening dollar. Light, sweet crude for June delivery rose to a record $119.93 a barrel in electronic trading on the New York Mercantile Exchange. The contract eased back to $119.04 a barrel by afternoon in Europe, up 52 cents from Friday's close of US$118.52. Brent crude futures rose 65 cents to $116.99 a barrel on the ICE Futures exchange in London.