Asia, brushing off news of increasing U.S. crude supplies, as traders took heart from rallies in global stock markets as an indication of overall investor optimism.

But others cautioned that oil prices wouldn't go much higher because the outlook for the global economy remains murky.

Benchmark crude for April delivery rose 71 cents to $48.85 a barrel by midday in Singapore on the New York Mercantile Exchange. Prices rose fell $1.02 on Wednesday to settle at $48.14.

Wall Street advanced Wednesday for the sixth time in seven days, buoyed by news the U.S. Federal Reserve plans to buy $1.25 trillion of government bonds and mortgage-backed securities.

The purchases are designed to help revive the housing market and drive down borrowing costs for everything from mortgages to credit cards.

Since the rally began last week, the Dow Jones industrial average has jumped 14.4 percent.

Asian stock markets, which have also risen steadily since last week, were mixed Thursday.

Still, some analysts doubt oil demand from developed countries, which is still reeling from a financial crisis and severe recession, can justify sustained trading above $50 a barrel.

"There is still plenty of uncertainty about the U.S. economy," said Gerard Burg, minerals and energy economist with National Australia Bank in Melbourne.

"Demand remains broadly weak. It's likely we'll see a pull back."

Oil is up despite signs that U.S. crude supplies are rising.

The Energy Information Agency reported crude inventories rose 1.94 million barrels for the week ended March 13.

The 353.3 million barrels of crude is the highest reported level in U.S. inventories since June 29, 2007.

Gasoline stocks surged by 3.2 million barrels, surprising analysts who had expected a draw down of 2.1 million barrels.

"We've seen a steady increase in U.S. oil inventories for the last six months," Burg said.

"There's very little on the supply side to indicate a push higher in prices."

In other Nymex trading, gasoline for April delivery rose 1.73 cents to $1.38 a gallon, while heating oil gained 2.64 cents to $1.29 a gallon.

Natural gas for April delivery was steady at $3.69 per 1,000 cubic feet.

In London, Brent prices rose 94 cents to $48.60 on the ICE Futures exchange. - AP

Earlier report

Oil prices fall on new US inventory report NEW YORK: Oil prices slumped Wednesday on a government report showing that U.S. crude and gasoline inventories are bulging with surplus supply. Benchmark crude for April delivery fell $1.02 to settle at $48.14 a barrel on the New York Mercantile Exchange. The Nymex April contract will expire Friday. The Energy Information Agency reported crude inventories rose 1.94 million barrels for the week ended March 13, in line with analysts surveyed by Platts, the energy information arm of McGraw-Hill Cos. The 353.3 million barrels of crude is the highest reported level in U.S. inventories since June 29, 2007. Gasoline stocks surged by 3.2 million barrels, surprising analysts who had expected a draw down of 2.1 million barrels in gasoline. Andrew Lipow, president of Lipow Oil Associates, said the build in gas inventories comes as refiners put units back online after a number of unscheduled maintenance problems around the country. "Those interruptions affected operations for various refineries, but they've returned to service," Lipow said. Prices have recently been bolstered by renewed optimism in stock markets, which some oil traders use as a barometer of overall investor sentiment. Still, months of massive layoffs, falling consumer demand and weak corporate profits have left some traders wary that the drop in crude demand reached a bottom. "We're seeing a bit of a sell-off after such a strong run-up" in oil prices, said Michael Lynch, president of Strategic Energy & Economic Research. The Commerce Department said Wednesday the deficit in the broadest measure of U.S. trade fell sharply in 2008 for the second consecutive year. Economists expect imports to shrink even more as the recession cuts into consumer buying power. The global recession is also cutting into U.S. exports. The World Bank said plunging exports continue to harm China's economy and cut its forecast of China's 2009 growth from 7.5 percent to 6.5 percent. Still, World Bank economists said they were confident in Beijing's ability to expand the world's third-largest economy despite the global turmoil. "We see China as a relative bright spot in a rather gloomy global economic picture," said David Dollar, the bank's country director for China. In Britain, the country's unemployment rate rose to its highest level in 12 years. The Office for National Statistics said more than 2 million people claimed unemployment benefits in January. Meanwhile, OPEC has been slashing production in hopes of drawing down a global surplus of crude. With oil trading well below OPEC's comfort level, the national budgets of some member countries are under strain. "Harmfully low prices are creating a damaging ripple effect, with diminished oil sector investments threatening the availability of much-needed future supplies," Saudi Arabian oil minister Ali al-Naimi said. On Wednesday, Iranian Oil Minister Gholam Hossein Nozari said that a plunge in crude prices has forced his country to pull money from other parts of its budget to support the oil industry. Nozari, who spoke at an OPEC meeting in Vienna, told The Associated Press that while some fields were still profitable at current prices, production at others had to be subsidized to maintain output at over 4 million barrels a day. Falling oil prices also forced Iranian President Mahmoud Ahmadinejad to propose an unpopular tax hike and plans to scrap costly state subsidies for fuel, water and electricity. The Organization of Petroleum Exporting Countries decided last week against shutting down production more than the previously announced cut of 4.2 million barrels per day.Instead, leaders said they'll rein in wayward members of the 12-nation group and make sure everyone is cutting as much as promised. Crude imports actually rose by 59,000 barrels compared with the previous week, according to the EIA. In other Nymex trading, gasoline for April delivery tumbled 5.81 cents to settle at $1.3657 a gallon, while heating oil dropped 1.07 cents to settle at $1.240 a gallon. Natural gas for April delivery fell 9.2 cents to $3.72 per 1,000 cubic