Wall Street declined amid early indications that the outcome of Italian elections calls into question the European Union's ability to lift itself from the sovereign debt crisis and recession.
Polls indicate that the vote in Italy, the euro-zone's third-largest economy, may have left the country with a split parliament. As Pier Luigi Bersani's centre-left coalition won control of the lower house, former prime minister Silvio Berlusconi's party looked set to take the senate, which might jeopardise austerity efforts.
"What we don't want to hear is a renewed fear about a euro-zone fracture," Art Hogan, managing director of Lazard Capital Markets in New York, told Reuters.
In afternoon trading in New York, the Dow Jones Industrial Average fell 0.14 per cent and the Standard & Poor's 500 Index slid 0.29 per cent. The Nasdaq Composite Index gained 0.15 per cent.
Europe's Stoxx 600 Index ended the session with a decline of nearly 0.1 per cent, though the region's national benchmark indexes advanced as markets earlier welcomed Bersani's lower house victory on initial exit poll results.