News that Spain had entered another recession renewed worries about the fragility of Europe's finances Monday and nudged stocks lower. The market ended its first losing month this year.
Disappointing economic reports and weak corporate earnings also weighed on stocks. The Standard & Poor's 500 index slipped 5.45 points to close at 1,397.91. For April, it was down 0.8 percent, its first month in the red since November.
The Spanish government said that the country's economy shrank in the first three months of the year, the second straight quarter of contraction.
The worry is that Spain's economy could be too big to rescue. It's twice as big as the combined economies of Greece, Portugal and Ireland, the three countries that have received bailout loans.
In the U.S., a drop in an index of Midwestern manufacturing and a slowdown in consumer spending last month added to worries that the economy is losing steam.
The Institute for Supply Management said its Chicago business barometer fell in April to the lowest level in more than two years. After weak readings for the New York and Philadelphia regions, the market reaction to the Chicago report could have been much worse, said Clark Yingst, chief market analyst at the brokerage Joseph Gunnar.
"It's very bad news in my opinion," Yingst said. "I'd have thought the market would come under more pressure than it has."
Weaker earnings reports from health insurer Humana and the owner of the New York Stock Exchange, NYSE Euronext, also hurt stock indexes.
The Dow Jones industrial average edged down 14.68 points to close at 13,213.63, but narrowly avoided its first monthly loss since September. The Dow finished April up less than two points.
The Nasdaq composite fell 22.84 points to 3,046.36. It posted a monthly loss of 1.5 percent.
Growing concerns about Spain knocked European markets lower on Monday. Spain's main stock index, the IBEX 35, sank 1.9 percent. France's CAC-40 lost 1.6 percent.
The dollar and U.S. Treasury prices edged up as investors parked money in low-risk assets.
Ratings agency Standard & Poor's downgraded Spain's government debt to just three notches above junk Friday. On Monday S&P lowered its rating for 11 Spanish banks, which are loaded with bad debt from a collapsed housing market.
Among stocks making big moves:
_ Barnes & Noble jumped 52 percent after Microsoft announced that it would invest $300 million to help Barnes & Noble compete with Amazon.com. The companies will create a subsidiary for Barnes & Noble's e-book and college textbook businesses. Microsoft also plans an application for Nook, Barnes & Noble's e-reader, on its Windows 8 tablets, which come out this fall. Microsoft's stock was flat.
_ Health insurer Humana fell 8 percent to after reporting a large drop in first-quarter profit as the company paid more in claims. The results fell short of Wall Street's expectations.
_ NYSE Euronext, owner of the New York Stock Exchange, lost 5 percent after reporting that its income plunged in the first three months of the year. Revenue from its trading business was weak, and the company abandoned a merger with the European exchange operator Deutsche Boerse.
_ Sunoco jumped 20 percent, the most of any stock in the S&P 500. The fuel-refining company agreed to be bought by Energy Transfer Partners, an operator of natural gas pipelines, for $5.3 billion.