Gains accelerated after a weekly U.S. government report showed just a small build in crude stocks and a fall in gasoline inventories even though crude imports into the country were at the highest weekly level ever.

U.S. light crude rose $1.21 to $43.05 a barrel - topping peaks hit in early June and the highest price since the New York Mercantile Exchange launched the contract in 1983. London Brent crude rose $1.06 a barrel to $39.60 a barrel, its highest level since October 1990, ahead of the first Gulf War.

Prices jumped after a company source said Russian bailiffs told YUKOS' four production units, which together pump 1.7 million barrels a day of oil, to halt sales of property - including oil.

YUKOS said it had not complied with the order and was continuing to operate while it sought clarification of what chief executive Steven Theede called a "misinterpretation".

YUKOS has said it faces imminent bankruptcy as courts seek to enforce a $3.4 billion tax debt for 2000.

The company pumps around a fifth of crude supply in Russia - the world's second biggest oil exporter behind Saudi Arabia after five years of rapid production growth.

STRETCHED TO THE LIMIT

The lack of a supply cushion in the event of an attack against the Middle East oil infrastructure has encouraged heavy buying from big money speculative funds.

If the YUKOS turmoil prevents Russian production from meeting forecasts for further growth, the global oil supply system will be even more pressed to meet rising demand, analysts say.

OPEC has already jacked up production to 30 million barrels per day - the highest level since 1979 - to meet breakneck consumption growth in China and the United States.

Saudi Arabia has led the supply increase, eager to stop prices rising to a level that would hurt world economic growth and stunt fuel demand.

Allowing for inflation, prices are about half those during the oil price shock that followed the 1979 Iranian revolution. Crude averaged $80 a barrel during 1980 when adjusted for inflation to 2003 prices, according to oil major BP.

OPEC President Purnomo Yusgiantoro of Indonesia said that the cartel was doing its best to get prices down. "We are very sincere about pushing the price to be stable below $30 per barrel," he told Reuters.

Venezuela's oil minister said OPEC had little spare capacity to help lower prices. "Most of the countries are near their production limits," Rafael Ramirez told Reuters.

Higher OPEC production helped push U.S. oil imports to the highest level ever last week at 11.3 million bpd, the U.S. Energy Information Administration said in its weekly report.

The high imports helped push crude stocks up 1.2 million barrels last week to 300.5 million barrels, around average for the time of year.

Refiners have struggled to turn ample crude supplies into higher refined product inventories, underpinning oil's price strength.

Gasoline stocks fell 700,000 barrels to 207.7 million barrels even though gasoline imports rolled in at the second highest weekly level ever, the EIA said.