New York Stock Exchange building in Wall Street in NYC

U.S. stocks ended at their lows for the year Friday, with the Dow Jones Industrial Average tumbling more than 400 points in three days, in a week dominated by concern over a slowdown in the economy.

The Dow ended down 191.24 points, or 1.9%, to 10,087.51, posting its biggest one-day decline since March 2003.

An already uneasy market began the biggest one-day selloff since May 19, 2003, after the Federal Reserve reported drops in manufacturing and other industrial production, and a Labor Department report showed higher oil costs driving up import prices.

The selloff was bolstered by lower-than-expected profits from IBM Corp., which led to fears that technology spending would be substantially worse than expected this year. Strong earnings from General Electric Co. and Citigroup Inc. were overlooked, but analysts said earnings would nonetheless be a key factor in overcoming the recent slump.

Trading volume on the New York Stock Exchange totaled one-point-nine (b) billion shares. Volume on the Nasdaq Market came to one-point-seven (b) billion shares.

A cautious forecast from Apple Computer unsettled investors, who are growing uneasy about the economy despite signs of continued improvement in the labor market.

The Labor Department reported that the number of Americans seeking unemployment benefits for the first time fell by ten-thousand last week, a second straight week of improvement.