Stocks dropped Wednesday as investors took some profits amid deepening concerns about Corporate America's near-term health.

The blue-chip Dow Jones industrial average fell 66.84 points, or 0.68 percent, to 9,834.54, down for the second session after clambering into bull-market territory on Monday. A bull market is defined as a gain of at least 20 percent from a recent low.

The technology-packed Nasdaq Composite Index slipped 5.53 points, or 0.29 percent, to 1,874.98. The broader Standard & Poor's 500 Index shed 5.64 points, or 0.49 percent, to 1,137.02.

"The market has been levitating -- you could pass a hoop over it and see there's not a lot of fundamental support," said Jeffrey Kleintop, chief investment strategist for PNC Advisors, who said his firm has sold bonds but is holding cash instead of buying stocks. "Jobless claims were down and that's a good sign, but we're still a long way from seeing the bottom in earnings for corporations."

Even bullish economic indicators, which showed a dwindling number of Americans lining up for first-time unemployment benefits and a bouncing U.S. consumer sentiment, couldn't overcome fears that a recovery is still some way off.

Strength in biotechnology stocks, lifted by a positive outlook from Amgen Inc., also helped stem the market's decline somehow. But marquee technology names like Microsoft Corp. kept major market gauges stuck in negative ground.

Trading lightened in late afternoon, with many market participants taking off before the Thanksgiving holiday on Thursday. The bond market closed early in what is typically one of the lowest volume weeks of the year.

Amgen, the world's No. 1 biotechnology company, projected sales of new anemia and arthritis products will bump its 2002 earnings growth rate up to 20 percent or slightly higher, compared with an expected 10 percent to 12 percent this year. Amgen jumped $4.07 to $61.98.

A decline in Microsoft dragged on benchmark stock indexes after the world's largest software maker said it will take about $375 million in charges to settle antitrust lawsuits and investment firm Salomon Smith Barney cut its rating on the company's stock, saying the share price is too high relative to the company's sales and earnings. Microsoft fell $1.37 to $64.03.

Enron Corp. , the most actively traded stock on the New York Stock Exchange for a second straight session, tumbled $1.98 to $5.01 amid worries the energy giant may not stay afloat long enough to be rescued through a proposed takeover by Dynegy Inc..

In mid-afternoon, the company said it secured the rest of its $1 billion credit line and reaffirmed its agreement to be taken over by Dynegy. But shares remained lower after the announcement.

"The latest spate of economic news has all been incrementally positive," said Erik Gustafson, portfolio manager at Stein, Roe & Farnham. "Those all serve to support and buttress this market. But the statistics are not so overwhelming that they can outdo traders' desires to take some profits."

The S&P 500 has climbed more than 17 percent since plunging to a three-year low on Sept. 21, while the Nasdaq Composite has rallied almost 32 percent, bolstered by hopes for improvement in corporate profits and the economy next year, as well as by U.S. progress in the war in Afghanistan.

The gains mean stocks have become expensive relative to earnings, some say. Companies in the S&P 500 are selling at 22.9 times next year's earnings, according to First Call. That's the highest ratio since 1991, excluding the high-flying days of 1999 to 2000, the firm said.

There were a few bright spots amid the latest earnings news. Amgen, the world's No. 1 biotechnology company, projected sales of new anemia and arthritis products will bump its 2002 earnings growth rate up to 20 percent or slightly higher, compared with an expected 10 percent to 12 percent this year. Amgen rose $4.07 to $61.98.

Other biotech shares surged, including Biogen Inc., which gained 87 cents to $56.74, and drugmaker Merck & Co. , which advanced $1.44 to $65.58.

Chiron Corp. slumped $4.50 to $45.59 after saying a late-stage clinical trial of a drug designed to treat the deadly blood infection sepsis proved ineffective in a clinical trial.

A decline in Microsoft dragged on benchmark stock indexes after the world's largest software maker said it will take about $375 million in charges to settle antitrust lawsuits and investment firm Salomon Smith Barney cut its rating on the company's stock, saying shares are too pricey relative to the company's sales and earnings. Microsoft fell $1.35 to $64.05.

"We were busy until 11 (a.m.) and then people started heading out the door," said Tom Schrader, head of listed trading for Legg Mason Wood Walker Inc.

About 1 billion shares changed hands on the New York Stock Exchange, while 1.5 billion traded on Nasdaq. Three shares fell for every two that gained on the NYSE, while advancers and decliners were even on the Nasdaq.

The Russell 2000 index, which tracks smaller company stocks, fell 1.59, or 0.4 percent, to 452.31. 

Overseas, markets were mixed Wednesday. Japan's Nikkei stock average finished up 0.8 percent. In Europe, Britain's FT-SE 100 rose 0.3 percent, while France's CAC-40 fell 0.8 percent and Germany's DAX index declined 0.2 percent.

Reuters and the Associated Press contributed to this report.