Updated from 3:29 p.m. EDT

The major averages closed at their lowest levels since April, as blue-chips and tech stocks were scorched by bad news from tech companies.


Dow Jones Industrial Average broke below the 10,000 level around midday and finished down 171.32 points, or 1.7%, to 9919.58. The last time the Dow closed below 10,000 was April 9. The

Nasdaq dropped 51.56 points, or 2.8%, to 1791.61, and the

S&P 500 was down 20 to 1129.

Sun Microsystems

(SUNW) - Get Report

was crushed, falling $2.36, or 17.6%, to $11.07 after the Unix systems maker said it probably won't be profitable in the fiscal first quarter. Earlier in the session, Sun hit a 52-week low of $10.40.

AOL Time Warner


lost $2.50, or 6.5%, to $36.


(GLW) - Get Report

slid $2.55, or 17.5%, to $12.05 after the company disclosed plans to cut 1,000 jobs from its fiber unit and temporarily shut down operations at plants in North Carolina. The company also offered a gloomy outlook for overall fiber market growth.


(MSFT) - Get Report

was under pressure after the European Commission expanded an investigation of the software giant. The stock fell 5.5% to $56.94.



was the most active stock on the

New York Stock Exchange, where it traded down 50 cents, or 7%, to $6.67. Mobile phone maker


(NOK) - Get Report

fell 83 cents, or 5.2%, to $15.30.

Looking at the major sectors, chips and Internet stocks took a pounding today, while biotech has sold off after trading higher for much of the day. In Treasuries, the 10-year note was down 9/32 to 101 17/32, yielding 4.804%.

Overseas, European stocks were lower. Telecom stocks fell following the Corning news, and the markets dropped after digesting the European Central Bank's decision to cut rates by a quarter of a percentage point. In London, the FTSE 100 fell 85 points, or 1.6%, at 5333. Japan's Nikkei 225 closed down 41 points, or 0.4%, to 10,939 as concerns over bad loans linger. Hong Kong's Hang Seng climbed 73 points, or 0.7%, to 11,316.