SINGAPORE (AP): Oil futures have hit an all-time high near US$121 a barrel in Asian trade on worries about threats to supply and a weakening of the U.S. dollar.

Light, sweet crude for June delivery rose to a record US$120.93 a barrel in electronic trading on the New York Mercantile Exchange on Tuesday. The contract later retreated to US$120.47 a barrel, up 50 cents from Monday's close.

Analysts say the surge in oil prices was partly driven by hopes that the U.S. economy will be spared a sharp downturn after the release of data showing an unexpected expansion in the U.S. service sector in April.

Supply outages or potential threats to supply in Iran, Nigeria and Iraq, and the greenback's decline, also supported prices.