Stocks ended mixed in New York after technology shares rallied from a deep slump in the final hour, pulling broad market indexes up with them.

On Wall Street, the Dow Jones industrial average dropped 21.73 - or by 0.2 per cent - to 9,275.88. The blue-chip index swung widely, rising as much as 40 points and shedding as much as 86 before trimming its losses in the final 30 minutes.

Broader stock indexes, which are more heavily stocked by technology shares, were lower for most of the day but popped into positive territory late in the session.

Computer stocks dropped after 3Com Corporation, which sells Internet data, voice and video systems, said late on Tuesday that third-quarter operating earnings would be far below analysts' expectations because of an "unexpected slowdown" in sales to businesses in the United States and Latin America.

3Com's statement followed similar warnings of soft computer sales from Compaq Computer and Micron Electronics, a unit of Micron Technology.