Wall Street fell as disappointing earnings from companies including AT&T made investors cautious in a market trading near record highs.
Later on Wednesday, Apple and Facebook are scheduled to report their quarterly results.
In afternoon trading in New York, the Dow Jones Industrial Average slipped 0.11 percent, the Standard & Poor's 500 Index fell 0.18 percent, while the Nasdaq Composite Index dropped 0.74 percent.
In the Dow, declines in shares of AT&T and Verizon, down 3.5 percent and 1.1 percent respectively, outweighed gains in shares of Boeing and Travelers, up 2 percent and 1.4 percent respectively. AT&T shares suffered amid concern about the company's profit outlook.
"These next few days are the most important of the earnings season as some big bellwethers report," Heinz-Gerd Sonnenschein, an equity market strategist at Deutsche Postbank, told Bloomberg News. "Earnings have not been great this quarter. Expectations had already been brought down quite dramatically and profit growth is weak year-on-year. The S&P 500 is holding up, but investors will need more of a signal to start buying into the market."
It wasn't all disappointment. Boeing posted quarterly results and a full-year outlook that reassured investors.
"We think investors will be breathing a sigh of relief," on free cash flow, Rob Stallard, analyst at RBC Capital Markets, said in a note about the air plane maker, according to Reuters. "The actual result has turned out far better than some feared."
Markit Economics' preliminary US manufacturing index slipped to 55.4 in April from a final reading of 55.5 in March.
"Manufacturers reported a solid start to the second quarter, with output growing at its fastest pace for over three years," Chris Williamson, chief economist at Markit, said in a statement. "The survey bodes well for further robust economic growth in the second quarter."
The US housing market, however, showed signs of weakness. Sales of new homes posted a surprise drop, slumping 14.5 percent to a 384,000 annualised pace in March, the lowest level in eight months.
"The weak tone of this report is a bitter pill for those, including ourselves, who have been looking for signs of a spring thaw in the housing recovery," Millan Mulraine, deputy chief economist at TD Securities in New York, told Reuters.
In Europe, the Stoxx 600 Index finished the day with a 0.6 percent slide from the previous close. The UK's FTSE 100 edged 0.1 percent lower, Germany's DAX fell 0.6 percent and France's CAC 40 decreased 0.7 percent.
The Markit Eurozone PMI composite output index rose to 54.0 in April, up from 53.1 in March, the highest since May 2011.
"The euro zone has started the second quarter on a solid footing," Markit's Chris Williamson said in a statement. "A welcome quickening in the pace of growth of business activity in April means the region is expanding at the fastest rate for almost three years."