U.S. crude prices fall sharply as inventory grows

TOKYO (Reuters) - U.S. oil futures tumbled more than 3 percent on Thursday to a one-week low around $50 a barrel after data showed a surprisingly sharp build in U.S. crude inventories.

U.S. crude for March delivery fell to a session low of $50.23 a barrel, down almost $2 from Wednesday's settlement. The contract was trading down $1.51 at $50.63 by 7.06 p.m. ET, after settling down $1.39 on Wednesday.

London Brent crude for April delivery was yet to trade, after settling $2 lower at $60.53 a barrel.

U.S. crude stocks rose by 14.3 million barrels last week, data by industry group the American Petroleum Institute showed after Wednesday's settlement, compared with analyst expectations of an increase of 3.2 million barrels. [API/S]

If the build is confirmed by closely watched U.S. Energy Information Administration data due at 11.00 a.m. ET, it will be the largest weekly growth since EIA data became available in 1982.

The market selloff accelerated on Wednesday afternoon following a fire and explosion at a gasoline processing unit in a refinery owned by Exxon Mobil in Torrance, California, near Los Angeles.

Despite the rally in crude prices over the past month from last month's multiple-year low on the back of fighting in the Middle East and a decline in U.S. rig counts, worries over a supply glut and sluggish demand again seemed to be taking center-stage, analysts said.

Crude imports by Japan, the world's fourth-biggest buyer, fell 7.2 percent last month from a year earlier, data showed on Thursday.

Trading was quiet in Asian hours as markets in China, Singapore and some other nations are closed for the Lunar New Year holidays.

(Reporting by Osamu Tsukimori; Editing by Joseph Radford)