Stocks tumble as Dow plunges below 9,000 for first time since 2003

— -- Stocks plunged in the final hour of trading Thursday, sending the Dow Jones industrial average down more than 675 points, or more than 7%, to its lowest level in five years after a major credit ratings agency said it was considering cutting its rating on General Motors

It was the seventh straight session of losses as investors worried recent moves by authorities worldwide to thaw frozen credit markets might not be enough to avert a global recession.

The Dow Jones industrial average, hurt by a steep decline in shares of GM, dropped 678.91 points, or 7.3%, to 8579.19. The blue chips hadn't closed below the 9,000 level since the June 30, 2003.

Much of the pain, again, came from stocks in the financial industries, ranging from mortgage finance and insurance companies. The result was a 75.02 point decline, or 7.6%, in the Standard & Poor's 500 to 909.92.

The Nasdaq composite dropped 95.21, or 5.5%, to 1645.12.

The Russell 2000 index of smaller companies fell 47.37, or 8.67%, to 499.20.

The declines came on the anniversary of the closing highs of the Dow and the S&P. The Dow has lost 5,585 points, or 39%, since closing at 14,198 a year ago. The S&P 500, meanwhile, is off 655 points, or 42%, since recording its high of 1,565.15.

Thursday's sell-off came as Standard & Poor's Ratings Services put GM and its finance affiliate GMAC under review to see if its rating should be cut. GM has been struggling with weak car sales in North America.

The action means there is a 50% chance that S&P will lower GM's and GMAC's ratings in the next three months.

S&P also put Ford Motor on credit watch negative. The ratings agency said that GM and Ford have adequate liquidity now, but that could change in 2009.

GM led the Dow lower, falling $2.15, or 31%, to $4.76, while Ford fell 58 cents, or 22%, to $2.08.

"The story is getting to be like that movie Groundhog Day," said Arthur Hogan, chief market analyst at Jefferies & Co. He pointed to the still-frozen credit markets, and Libor, the bank-to-bank lending rate that remains stubbornly high despite the Fed's recent rate cut.