Transportation stocks were among the worst performers. Shares of CH Robinson Worldwide fell 9.7 percent to $60.50 and the stock was the biggest percentage loser on the Nasdaq 100 after the freight transport company posted a lower-than-expected adjusted quarterly profit.
Without a strong catalyst, the market could struggle to continue its rally, analysts said. The benchmark S&P 500 index has advanced 6 percent this year, reaching its highest since December 2007, while the Dow Jones industrial average has risen above 14,000 recently.
Bank of America-Merrill Lynch analysts see a near-term pullback likely, based on strong equity inflows at the start of the year, said Dan Suzuki, the bank's equity strategist in New York.
"The fact that we've gone since November without seeing one, from a timing perspective, it wouldn't be a surprise to see one now."
With fourth-quarter earnings nearing an end, the market will be losing one of its big supports, said Frank Lesh, a futures analyst and broker at FuturePath Trading LLC in Chicago. "That's one thing that's been holding the market up," he said.
Shares of Time Warner Inc jumped 4.1 percent to $52.01 after reporting higher fourth-quarter profit that beat Wall Street estimates, as growth in its cable networks offset declines in film, TV entertainment and publishing units.
The Dow Jones industrial average was up 7.22 points, or 0.05 percent, at 13,986.52. The Standard & Poor's 500 Index was up 0.83 points, or 0.05 percent, at 1,512.12. The Nasdaq Composite Index was down 3.10 points, or 0.10 percent, at 3,168.48.
Amazon.com shares, down 1.7 percent at $262.22, led the decline on the Nasdaq.
Also causing some strain on the market, investors have been speculating about leadership changes in Spain and Italy and watching for comments from European leaders, analysts said. European Central Bank policymakers are due to meet Thursday.
The Dow Jones Transportation average was down 0.2 percent after hitting another record high on Tuesday. The average is up 10.7 percent for the year so far and has made a series of new highs since mid-January.
According to Thomson Reuters data, of 301 companies in the S&P 500 that have reported earnings, 68.1 percent have exceeded analysts' expectations, above a 62 percent average since 1994 and 65 percent over the past four quarters. In terms of revenue, 65.8 percent of companies have topped forecasts.
Fourth-quarter earnings for S&P 500 companies are estimated to have risen 4.7 percent, according to the data, above a 1.9 percent forecast at the start of the earnings season.
Walt Disney Co's stock was up 0.4 percent at $54.52, after the company beat estimates for quarterly adjusted earnings and gave an optimistic outlook for the next few quarters.
Volume was roughly 6.5 billion shares traded on the New York Stock Exchange, the Nasdaq and the NYSE MKT, compared with the 2012 average daily closing volume of about 6.45 billion.
Advancers outpaced decliners on the NYSE by roughly 17 to 12 and on the Nasdaq by about 13 to 11.