While second-quarter earnings in the financial and technology sectors came in above estimates, stocks moved in and out of negative territory for much of the day, partly because of options expirations tomorrow.

In addition, investors were increasingly concerned about third- and fourth-quarter profit outlooks, as well as a number of economic and political issues, analysts said.

"It's extremely frustrating. Earnings are good, fundamentals are good, but all these other worries — terrorism, oil prices, interest rates, the election — are keeping people on the sidelines," said Richard A. Dickson, senior market strategist at Lowry's Research Reports.

"I think the great earnings we have here were baked into the market last year. Now we're waiting for some other reason to go up or down."

According to preliminary calculations, the Dow Jones industrial average fell 45.64, or 0.4 percent, to 10,163.16.

Broader stock indicators were modestly lower. The Standard & Poor's 500 index was down 4.78, or 0.4 percent, at 1,106.69, and the Nasdaq composite index slipped 2.17, or 0.1 percent, to 1,912.71.

The producer price index dropped 0.3 percent in June, according to the Labor Department — a sign that inflation might not be as serious an issue as some had feared. Economists had expected a slight rise. And the Commerce Department said inventories rose 0.4 percent in May, while sales climbed 0.7 percent, signs that businesses are increasing their investments and that consumers are rewarding their efforts.

Jobs, however, continue to be an area of concern. First-time jobless claims rose by 40,000 for the week to 349,000. The Labor Department blamed seasonal adjustments at the nation's automakers for the increase.

With good and bad news in equal measure, most investors chose to wait out the session in advance of IBM Corp.'s earnings, which came out after the close. IBM, which beat estimates by 4 cents per share, was down 11 cents at $84.02 for the day, but rose 64 cents to $84.66 in after-hours trading.

"I think some people are looking to IBM, but there are plenty who are just waiting, period," said Matt Kelmon, portfolio manager of the Kelmoore Strategy Funds. "Nobody's worried that the market's about to cave, but there's no catalyst for the upside either."