The disclosure yesterday from WorldCom, the embattled telecommunications company, that it was investigating further accounting irregularities provided the latest impetus for investors to dump shares in disgust, particularly in the technology sector.

According to preliminary calculations, the Nasdaq composite index fell 45.95, or 3.3 percent, to close at 1,357.85, after falling 4.1 percent yesterday. It was the lowest close for the index since May 19, 1997.

Market watchers described the declines as an emotional response to a seemingly relentless string of disclosures of questionable bookkeeping in recent months that have badly shaken confidence in the stock market.

"It seems like an acceleration of bad news these days," said Brian Bruce, director of global investments at PanAgora Asset Management in Boston. "People are just focusing on every bit of bad news that comes out now. This is clearly the flip side of the bubble mentality – people are looking for the next bad thing."

The Dow Jones industrial fell 102.04, or 1.1 percent, to 9,007.75. The S&P 500 was down 20.56, or 2.1 percent, at 948.09, dropping below its post-Sept. 11 low and at its lowest close since it reached 936.46 on Dec. 26, 1997.

Stock indicators have been on an almost uninterrupted slide since the middle of May as a wave of disclosures about questionable accounting practices at several major U.S. firms badly damaged investor sentiment, which was already shaken by the collapse of energy giant Enron.

Investors said the market is still testing how badly confidence in U.S. companies has been damaged by accounting problems at Global Crossing and the cable TV company Adelphia Communications and the arrest of the former CEO of ImClone Systems.

"I think it runs deeper than most people are willing to admit," said Alan Ackerman, executive vice president at Fahnestock & Co. "The question is whether we have a crisis of confidence or a contraction of confidence. Judging from the fact that the market is hardly acting as a magnet for money right now, I think it's fair to say that it could trade lower still."

The bad news about corporate accounting continued to mount as the French newspaper Le Monde reported that Vivendi Universal sought to pad its 2001 records by $1.47 billion related to its sale of its stake in the pay-television company BSkyB. The company said it followed appropriate accounting rules.

The report came as the embattled chairman of Vivendi Universal, Jean-Marie Messier, was forced out by his board. Messier had angered shareholders with a two-year buying binge that assembled a large but debt-ridden conglomerate comprising both media and water utility assets.

Investors were also eager to trim their exposure ahead of the long Independence Day weekend. U.S. financial markets will be closed on Thursday and operate on an abbreviated schedule on Friday.

Declining issues outnumbered advancing ones by a 3-to-1 ratio on the New York Stock Exchange, where volume came to 1.7 billion shares, above the pace of 1.2 billion shares at the same time yesterday.

The Russell 2000 index was off 14.89, or 3.3 percent, at 432.84.