US economic data and warnings from the US Fed that tough times are not over led Wall Street to its worst day since the 1987 stock market crash, wiping out earlier optimism fueled by government steps to avert a financial meltdown. Japan's Nikkei index dived 9.55 percent in early trade.

US crude for November delivery fell US$1.56, or about 2 percent, to US$72.98 a barrel by 9:54pm EDT. The front-month contract has lost nearly a third in value in three weeks, the steepest such decline since it began trading in 1983. London Brent crude fell US$1.30 to US$69.50.

Crude now stands more than 50 percent off its July peak above US$147, and analysts have scaled back global demand growth estimates after a recent slew of gloomy data that has overshadowed OPEC's talk of possible production cuts and a hurricane that is disrupting Caribbean refining operations.

US retail gasoline demand last week fell more than 9 percent year-on-year for a second straight week as consumer spending slowed.