SINGAPORE ? Oil prices were mixed in Asian trade Wednesday ahead of a closely watched report on energy demand in the United States, the world's biggest energy consumer.

New York's main contract, light sweet crude for April delivery, dropped four cents to $81.45 a barrel.

London's Brent North Sea crude for April delivery turned higher and was up four cents to $79.95 a barrel in afternoon trade.

Analysts said trading was volatile as investors waited for signs of firmer demand in the United States after an industry report showed a surprise build-up of crude stocks indicating weaker demand.

The American Petroleum Institute (API) said Tuesday crude stockpiles for the week ended March 5 rose 6.5 million barrels. Analysts polled by Platts had anticipated an increase of 2.1 million barrels.

"The API reported quite bearish results yesterday. The crude build-up was larger than expected," said Serene Lim, a Singapore-based oil analyst with ANZ bank.

She said the focus would now be on a report by the US Department of Energy on oil inventories to be released later Wednesday for indications on energy demand in the United States.

"The market currently lacks direction and has been moving in a narrow range between $80 and $82," said Ken Hasegawa, manager for energy risk at Newedge Japan brokerage in Tokyo.

Crude prices had also been under pressure by a stronger greenback, which makes dollar-priced oil more expensive, analysts said.

The dollar was steady in Asia on Wednesday as traders looked ahead to upcoming US economic data, while keeping a close watch on Europe's public debt woes.

The euro was almost flat at $1.3599 in Tokyo afternoon trade, compared with 1.3598 in New York late Tuesday, and at 122.49 yen against 122.35. The dollar edged up to 90.07 yen from 89.96.