LONDON (AFP) — World oil prices have climbed slightly in slow trading, but dealers said they remained under pressure from high stockpiles and forecasts of warmer weather in the United States.

In New York, a barrel of light sweet crude for January delivery rose by 45 cents to 59.69 dollars in electronic trading at 11:15 GMT.

In London, Brent North Sea crude contracts for January delivery climbed 53 cents to 59.33 dollars.

The market in the United States remained closed Friday for a second day because of the Thanksgiving holiday, which tended to cause sharper movements.

"The market is a little lackluster. It seems to be under a little bit of pressure still as there's no shortage of wet barrels around, that's for sure," said Robert Laughlin, a broker at Man Financial.

"I think for the time being the sentiment is that generally we're looking to have another little test on the downside towards 55 dollars," he said Friday.

Prices have also been under pressure since the U.S. Energy Information Administration (EIA) reported that crude oil stocks rose by 5.1 million barrels last week to total 341.1 million -- well above average levels.

The market expected a gain of around 600,000 barrels.

The surprise hike in gasoline stockpiles also eased prices as millions of Americans took to the road for the long Thansgiving weekend.

On Thursday, prices weakened further as better weather in Alaska allowed tankers to resume loading oil at the Valdez export terminal, which had been closed since Monday.

The bad weather had cut flow through Trans Alaska Pipeline by up to 35 percent.

"Further weakness yesterday came from news that the Trans Alaska Pipeline is now running at half of the normal 800,000 bpd throughput thanks to improving weather conditions," according to Sucden analyst Michael Davies.

Temperatures in the northeastern United States, which consumes the most heating oil in the world, are expected to be above normal until December 4, but they could drop afterward, forecasters there said.

"Despite the bearish sentiment on the market at the moment, the risks to the upside remain from cold weather and also from the potential for another OPEC supply cut when the group meets again next month," Davies said.

The Organization of Petroleum Exporting Countries, which exports 40 percent of the world's crude, pledged to cut output by 1.2 million barrels per day starting November 1 in a bid to shore up prices, which have shed nearly 20 dollars since August.

However, until now the market has been skeptical about how seriously the cartel will implement the decision, with most analysts expecting a reduction of only about 600,000 barrels a day.