NEW YORK: Oil prices slid on Wednesday after official data revealed an unexpected rise in crude stockpiles in the United States, the world's biggest energy consumer, traders said.

New York's main oil futures contract, light sweet crude for August delivery, slumped 2.45 dollars to close at 134.55 dollars per barrel.

In London, Brent North Sea crude for August slid 2.13 dollars to settle at 134.33 dollars.

After a slight opening retreat, oil prices plunged as low as 132 dollars following the release of the US Department of Energy's weekly snapshot on energy reserves.

While gasoline reserves, under particular scrutiny as the summer holiday "driving season" gets underway, decline a notch, it was the crude oil reserves that drew the market's notice.

After five consecutive weeks of declines, and analysts' consensus forecast of a drop of 1.1 million barrels in the week ended June 20, crude stockpiles climbed by 800,000 barrels to 301.8 million.

The market shrugged off the Federal Reserve's widely anticipated decision to hold its key interest rate unchanged at 2.0 percent.

Oil prices have almost doubled over the past year after striking record highs of close to 140 dollars last week.

As investors worried about geopolitical tensions that could affect supply, the Anglo-Dutch oil giant Shell reassured the market about its situation in Nigeria.

Shell said on Tuesday that it had resumed operations in the Bonga offshore oilfield that had been halted after an attack by militants last week cut output by 200,000 barrels a day.

Militants also blew up a key Nigerian supply pipeline run by Chevron late last week.

Adding to market jitters was Saudi Arabia's announcement on Wednesday that it has arrested 701 Islamists in the past six months on suspicion of plotting attacks on oil installations.

Saudi Arabia, the world's largest exporter, agreed at the weekend to raise its daily output by more than 200,000 barrels to 9.7 million.

However, OPEC president Chakib Khelil and other oil producers are opposed to higher output, blaming rocketing prices on speculative buying by funds.

Consuming nations, led by the United States and Britain, want the Organisation of the Petroleum Exporting Countries to pump more oil to ease tight supplies and sky-high prices that are fuelling inflation and dampening economic growth.

The OPEC cartel produces about 40 percent of the world's crude. - AFP/de