The Nasdaq rose 143.94, or 4 percent, to close at 3,774.03, and the Standard & Poor's 500 index edged up 3.93 to 1,464.92.
The Dow fell 57.40 to 10,888.10, led by AT&T, which spun off its wireless division. AT&T Wireless gained $2.31 to $31.81 by the 1 p.m. PT close of regular trading. More than 137 million shares changed hands.
Intel climbed $4.50 to $125.31, and Microsoft rose $1.81 to $69.81. Microsoft released details about a new version of its Office suite for Macintosh, dubbed Office 2001, which will feature integrated email and contact management software. Shares of Apple climbed $5.44 to $126.75.
The CNET tech index gained 86.07 to 3,049.76, boosted by MCI WorldCom and VeriSign.
Winners edged out losers, with 72 of the 99 stocks in the index rising and 27 falling.
Of the 18 sectors tracked, semiconductor equipment companies posted the sharpest gains, climbing 8 percent. Communications services were the only laggards, falling a slim 0.8 percent.
The initial public offering of Metawave Communications, a provider of antenna systems for cellular networks, was a large percentage gainer on the Nasdaq Stock Market. It jumped $4.56, or 50 percent, to $13.56. Volume topped 6.1 million shares.
Among members of the CNET tech index, MCI WorldCom and VeriSign posted strong gains.
MCI WorldCom rose $4.50, or 11 percent, to $45.38 on strong earnings. VeriSign rose $19.25, or 18 percent, to $126.28. Network Solutions, which will be bought by VeriSign, posted favorable earnings and rose $20.56, or 18 percent, to $135.94.
The Philadelphia semiconductor index rose 74.28, or 7 percent, to 1,135.12, led by chip equipment maker KLA-Tencor, which gained $7.25 to $70.94.
Six major airlines unveiled plans to start an Internet marketplace to handle about $32 billion in annual purchases, including fuel, engines and maintenance services.
EarthLink Network, a dial-up Internet service provider, said it plans to waive all setup costs for high-speed Net access to boost its broadband customer base. The company's shares rose 25 cents to $18.06.
Healtheon/WebMD founder Jim Clark said the Internet health care company will make money later this year. But analysts and even the company's chief executive have their doubts. Its shares rose $1.19 to $19.94.
Internet banker CheckFree Holdings rose $14.81, or 37 percent, to $54.38 after the company said it will buy Bank of America's online bill-payment service to gain access to the bank's 30 million customers.
Tomorrow, all eyes will be Western Digital and US West. Western posted earnings today after the markets closed, and US West will report tomorrow.