"The marketplace is a little too sanguine, and expectation levels might have to be tempered going forward," said Stephen Massocca, president of Pacific Growth Equities.

The Dow Jones industrial average closed down 69.93, or 0.7 percent, at 9,721.79, for a three-day loss of 91 points.

The Standard & Poor's 500 index fell 10.75, or 1 percent, to 1,039.32, and the Nasdaq composite index declined 37.78, or 1.9 percent, to 1,912.36. For the week, the Dow rose 0.5 percent, the Nasdaq lost 0.2 percent and the S&P edged up 0.1 percent.

Poor earnings reports from several companies late Thursday, including Sun Microsystems Inc. and DoubleClick Inc., weighed down technology shares in yesterday's trading.

EBay Inc. reported a 69 percent surge in profits, but analysts said the online auction house's period of rapid growth may be fading. EBay's shares fell $2.64 to $54.86 on the Nasdaq Stock Market.

Sun fell 7 cents at $3.56 in heavy trading on the Nasdaq after reporting a wider-than-expected loss. The computer maker continues to struggle with weak demand and questions about its strategy.

DoubleClick plunged $2.98 to $9.26 after the online advertising company gave an outlook for its fourth quarter performance that missed Wall Street's estimates.

In one encouraging economic indicator, the Commerce Department reported that residential construction rose in September from the previous month.