At around 0140 GMT on Wednesday, the price of London's Brent North Sea crude for June delivery struck 74.97 dollars per barrel.

That was identical to the all-time high forged late Tuesday as supply fears lingered over Iran, the world's fourth-biggest crude producer.

Later Wednesday, the contract climbed by 14 cents from the previous day's close to stand at 74.78 dollars per barrel.

Meanwhile New York's main contract, light sweet crude for delivery in June, rose 11 cents to 74.72 dollars per barrel in electronic deals before the market's official opening on Wednesday.

New York crude is near its all-time high of 75.35 dollars a barrel, reached on April 21, as concerns remain over Iran, Nigeria and Bolivia's decision to nationalize its gas and oil industry, dealers said.

"Oil prices are back within touching distance of 75 dollars per barrel as tight fundamentals and concerns over Iran and Nigeria look likely to bring another test" of the barrier, Barclays Capital analyst Kevin Norrish said.

UN Security Council powers readied for talks Wednesday over Iran's nuclear programme, after envoys from the top five UN powers demanded a "firm" response to its refusal to halt uranium enrichment.

Washington and Europe fear Iran is trying to develop nuclear weapons under cover of a stated drive for atomic energy, and want to invoke Chapter 7 of the UN Charter -- language that would open the way for sanctions and possibly even force as a way to freeze its activities.

Market watchers fear that Iran could retaliate against such action by slashing crude exports.

Iran currently exports about half of its daily output totalling four million barrels, and the country is the second-biggest member of the Organization of Petroleum Exporting Countries.

Meanwhile, OPEC's daily "basket" price, based on crude prices from the cartel's 11 member countries, has hit a historic high point of 68.4 dollars (54.3 euros) per barrel, OPEC data showed on Wednesday.

The OPEC basket traditionally gives a value below other key oil prices, such as London Brent crude.

Later on Wednesday, the US Department of Energy publishes its weekly report on energy stockpiles in the United States.

All eyes will be on the level of gasoline or petrol reserves, ahead of the start of the peak-demand US driving season which starts at the end of May.

"Gasoline remains the key number for the market to focus on, with a smaller than expected fall likely to lead the market lower," said analysts at the Sucden brokerage.

London analysts are predicting a drop in gasoline stocks of between 300,000 and 650,000 barrels during the week to April 28.

The reading will be crucial for the oil market because demand for motor fuel hits a peak during the so-called driving season, when many Americans take to their cars for vacations.

Sliding US gasoline supplies have been a key driver of recent record oil prices.

Crude futures have also been supported by rebel attacks on Nigeria's foreign-owned oil and gas industry in the southern Niger Delta. The attacks have cut Nigeria's total exports of 2.6-million-barrels per day by about a quarter.