NEW YORK (Reuters) - Oil gave back most of its gains to trade flat on Thursday as worries about high U.S. crude inventories offset early support from a gasoline rally and technical charts calling for higher prices.

An employee holds a gas pump to refill a car at a petrol station in central Seoul April 6, 2011. REUTERS/Lee Jae-Won

A two-week high in the dollar also weighed on crude despite a surge in share prices on Wall Street, which is normally supportive to oil.

Brent was down one penny at $47.84 a barrel by 1:42 p.m. EDT (1742 GMT). The global crude benchmark finished down 86 cents, or 1.8 percent, on Wednesday, hitting an October low of $47.50.

U.S. crude’s West Texas Intermediate (WTI) oil slipped 10 cents to $45.10. It settled down $1.09, or 2.4 percent, in the previous session, falling to a three-week low of $44.86.

Gasoline rose as much as 3 percent in early trade, pulling crude prices along, after Wednesday’s U.S. government data showed a 1.5 million-barrel decline in gasoline stockpiles last week, compared with a 858,000-barrel drop forecast in a Reuters poll.

Analysts had also cited technical support for Wednesday’s early gains, as Brent held above $46.

Oil eventually relinquished its gains as focus returned to last week’s big build in crude stockpiles - 8 million barrels - which was more than double that forecast by analysts in the Reuters poll.

The fourth weekly build in crude inventories came despite a pick-up in oil processing works during the autumn maintenance season for U.S. refineries.

“The high crude stock is the one factor weighing most on the market at the moment,” said Dave Thompson at Powerhouse, a commodities-focused brokerage in Washington.

Chris Jarvis of Maryland-based energy consultancy Caprock Risk Management concurred. “We have had 22 million barrels of oil put back in storage over the last four weeks, with the refinery maintenance season just halfway through. The fundamentals are just too heavy for the recent bullish technicals.”

Higher stockpiles aside, OPEC’s inability to get oil producers to agree to meaningful measures to boost prices will also weigh, traders said.

A meeting of oil experts from OPEC and non-member countries ended on Wednesday without any concrete price support measures despite discussing the risk low oil prices would have on investment in new supplies.

“There are no signs of any sort of production cuts, which would have to start from within OPEC,” said John Macaluso, trader in crude oil spreads at Tyche Capital Advisors in Laurel Hollow, New York.