Oil prices hit their highest level in nearly three months on Monday as a US plan to purge banks of toxic assets brightened the outlook for flagging energy demand.
US crude rose $US1.73 to settle at $US53.80 a barrel, having earlier climbed to $US54.05, its highest price since 1 December.
London Brent crude rose $US2.25 to $US53.47.
Dealers said the plan to unburden banks of toxic assets could brighten the outlook for global business and consumer energy demand, which has been shrinking for the first time in a quarter century.
An oil strike in Brazil encouraged crude's gains, dealers said. Workers at Brazilian energy company Petrobras began a five-day strike on Sunday in a protest over job cuts, pay and conditions, a union leader said. By Monday afternoon, one Brazilian oil platform had been shut as a result of the strike.
A similar strike in July in South America's second-largest oil producer had no material effect on production.
US crude oil has climbed from below $US33 last December due in part to aggressive supply cuts from the Organization of the Petroleum Exporting Countries.
However, prices remain almost $US100 below last summer's peak as the global economic crash erodes consumption.
