Stocks fell sharply yesterday, deepening a late August rout and burying the Dow Jones industrial average below 10,000 for the first time since April 9th, as fresh pessimism from Sun Microsystems and others magnified fears about the weak economy and profits.

The Dow tumbled 171.32 points, or 1.70 percent, to 9,919.58, according to the latest data. Year-to-date, the Dow is down 8 percent.

The technology-heavy Nasdaq composite index fell 51.50 points, or 2.79 percent, to 1,791.67, a level unseen since April 9th. The benchmark Standard & Poor's 500 index fell 19.53 points, or 1.7 percent, to 1,129.03, also the lowest finish since April 9th.

So far this year, the Nasdaq is down 27.5 percent and the S&P 500 down 14.5 percent.

Sun Microsystems said late Wednesday it stands to lose money this quarter after Japanese and European sales failed to meet expectations amid sluggish economic growth. Sun, the most heavily traded on Nasdaq, fell $2.26 to $11.07. Earlier, the shares fell to $10.40, the lowest since late December, 1998.