US STOCKS-Wall St extends losses, Nasdaq falls 3 pct

(Updates prices)

NEW YORK, Sept 4 (Reuters) - U.S. stocks plummeted on Thursday, with the Nasdaq slumping more than 3 percent, as investors grew anxious over more signs of weakness in the U.S. labor market and sluggish growth overseas.

The market sagged from the opening bell after data showed an unexpected jump in the number of filings for jobless benefits while a report by ADP Employer Services showed private employers cut 33,000 jobs in August.

Selling grew more fierce as the day went on, accelerating when Terex Corp (TEX.N: Quote, Profile, Research, Stock Buzz), a U.S. maker of construction and mining equipment, cut its 2008 sales and profit forecast, citing weak demand in Western Europe and North America. Shares fell 20 percent to $37.46.

Traders also said the S&P 500 index's break below a key technical level added to selling pressure.

The Dow Jones industrial average .DJI was down 306.87 points, or 2.66 percent, at 11,226.01. The Standard & Poor's 500 Index .SPX was down 33.39 points, or 2.62 percent, at 1,241.59. The Nasdaq Composite Index .IXIC was down 63.77 points, or 2.73 percent, at 2,269.96. (Editing by Kenneth Barry)