Oil prices drifted sideways on Wednesday ahead of an expected build in US crude and gasoline stocks that could soothe summer supply concerns for the world's biggest energy consumer.
US light crude dipped two cents to $34.95 a barrel, while London's Brent crude lost 15 cents at $31.20, after jumping 66 cents overnight on a gasoline-led rally.
"I see the short-term trend to the downside," said a broker based in London.
"I think the US data will be bearish and we'll see a lot of fund-liquidation on the back of it, but the market is a little nervous in case today's numbers are not as bearish as expected."
US crude stocks have risen sharply recently, adding more than 13 million barrels in the last fortnight prior to April 2 due to increased imports, especially from Saudi Arabia.
A Reuters survey of 10 analysts on Tuesday forecast crude inventories would rise by an average two million barrels in the week to April 2. But the poll was split with four of the participants forecasting a fall in stock levels and some industry analysts now unsure whether the rising trend would continue.
A poll of eight analysts on Monday called for a draw of half million barrels and a New York broker said on Wednesday: "There is some speculation of a small draw in crude."
The US government's Energy Information Administration (EIA) will release its weekly report on oil inventories on Wednesday.
On Tuesday survey estimated gasoline inventories would rise by 1.43 million barrels, extending the 1.4-million-barrel increase reported by the EIA last week.
As concerns over a summer driving season supply crunch lingered, the market grew increasingly restless over the US government's resolve to implement some states' requests for a waiver to requirements for cleaner-burning fuel.