New York's main oil contract, light sweet crude for delivery in May, plunged by 3.34 dollars to 99.20 dollars per barrel. The April contract expired on Wednesday after plummeting by 4.94 dollars.

Elsewhere on Thursday, London's Brent North Sea crude for May fell 2.30 dollars to 98.42 dollars per barrel.

'Crude fell below 100 dollars a barrel as fears of a US recession, its impact on the rest of the world, and on oil demand growth continue to dominate headlines,' said Sucden analyst Michael Davies on Thursday.

'Oil futures have fallen around 10 per cent now since the 111.80-dollar record high hit on Monday.'

This week has been a remarkable rollercoaster ride for the oil market.

Prices scaled historic heights on Monday as they were energised by the weak dollar and as investors sought a safer refuge for their cash than volatile world stock markets.

New York crude hit a record 111.80 dollars and Brent oil struck an historic 107.97 dollars on the back of the plunging US dollar, which hit a lifetime low against the euro.

The weak US currency encourages demand for dollar-priced commodities because they become cheaper for buyers using stronger currencies.

But oil prices closed sharply lower on Monday as traders feared that rising financial markets turmoil could damage the outlook for oil.

On Tuesday, crude surged by more than three dollars after the US Federal Reserve slashed US interest rates, stoking expectations of strong energy demand in key consumer the United States.

In a fresh twist on Wednesday, prices spiralled lower after a US government energy report signalled softening demand in the world?s biggest economy.

The US Energy Information Administration (EIA) said crude stocks rose by just 200,000 barrels to 311.8 million barrels in the week ended March 14, about average for this time of the year. Markets were expecting stocks to rise by around 2.3 million barrels.

The EIA also reported unexpectedly large declines in both US gasoline and distillate supplies.

The market also plunged because traders remained concerned about worsening credit conditions the world over which are threatening to derail global economic growth.

'Once again, market headlines are featuring concerns about the impact of the ongoing subprime crisis on the US economy and its impact on US oil demand growth,' added Mr Davies.

'These fears were highlighted by weaker demand numbers for distillates and gasoline in the weekly EIA report.' -- AFP