The Nasdaq fell 106.25 to close at 3,538.71, and the Standard & Poor's 500 index dropped 10.59 to 1,437.21.
The Dow inched up 7.54 to 10,777.28, led by General Motors and Coca-Cola.
Sellers cut a swath of red across the technology industry. Of the 18 sectors tracked, none gained. Server hardware makers and e-tailers posted the sharpest drops, falling 6 percent and 5 percent, respectively. PC hardware makers were the smallest losers, dropping a relatively modest 1 percent.
At the end of regular trading, Intel was up 75 cents at $123.94. Microsoft dropped $1.50 to $66.19.
The government responded to Microsoft's remedy proposal for its antitrust suit, saying the proposal to keep the company intact while accepting restrictions on its business practices would not prevent Microsoft from abusing its monopoly.
The initial public offering of New Focus, a fiber-optic equipment maker, was the biggest percentage gainer on the Nasdaq Stock Market. The shares jumped $31, or 151 percent, to $51. Volume topped 11.4 million shares.
The CNET tech index lost 74.47 to 2,631.22, dragged lower by shares of WorldCom and Sun Microsystems. Losers edged out winners, with 81 of the 99 stocks in the index falling, 16 rising and two remaining unchanged.
WorldCom fell $2.44 to $39.56 on a volume of 38.6 million shares, making it the second-most-actively traded company on the Nasdaq. A Justice Department panel recommended that the company's merger with Sprint be blocked, which may point to a growing trend of antitrust regulation.
Internet equipment maker Sun fell $5.44 to $80.88, while Parametric Technology, a maker of chip design software, fell $1.22, or 12 percent, to $9.34.
Shares of Lycos got a breather as investors scooped up its shares on positive earnings news, reversing the stock's recent decline during the past few days.
The Internet portal rose $4.72, or 8 percent, to $62.31 as investors continue to mull the company's merger with Terra Networks. Investors were not as kind to Terra, which crawled up 13 cents to $47.13.
The Philadelphia semiconductor index fell 25.32 to 1,002.41, led by chipmaker Altera, which lost $5.56 to $84.06.
ADC Telecommunications beat analysts' earnings expectations, but the stock fell $1.88 to $60.44. The company said its CEO will retire by the end of next year.