Italy faced political deadlock on Tuesday after a stunning election that saw the anti-establishment 5-Star Movement of comic Beppe Grillo become the strongest party in the country but left no group with a clear majority in parliament.
The center-left coalition led by Pier Luigi Bersani won the lower house by around 125,000 votes and claimed the most seats in the Senate but was short of the majority in the upper house that it would need to govern.
Bersani claimed victory but said it was obvious that Italy was in "a very delicate situation". Party officials said the center-left would try to form a government but it was unclear what its options would be.
Neither Grillo, a comedian-turned-politician who previously ruled out any alliance with another party, nor Silvio Berlusconi's center-right bloc, which threatened to challenge the close tally, showed any immediate willingness to negotiate.
(Read More: Italy Election Forecasts Point to Political Gridlock)
World financial markets reacted nervously to the prospect of a government stalemate in the euro zone's third-largest economy with memories still fresh of the financial crisis that took the 17-member currency bloc to the brink of collapse in 2011.
Italy's borrowing costs have come down in recent months, helped by the promise of European Central Bank support but the election result confirmed fears that it would not produce a government strong enough to implement effective reforms.
Grillo's surge in the final weeks of the campaign threw the race open, with hundreds of thousands turning up at his rallies to hear him lay into targets ranging from corrupt politicians and bankers to German Chancellor Angela Merkel.
In just three years, his 5-Star Movement, heavily backed by a frustrated generation of young Italians increasingly shut out from permanent full-time jobs, has grown from a marginal group to one of the most talked about political forces in Europe.
Its score of 25.5 percent in the lower house was just ahead of the 25.4 percent for Bersani's Democratic Party, which ran in a coalition with the leftist SEL party and it won almost 8.7 million votes overall, more than any other single party.
"The 5-Star Movement is the real winner of the election," said SEL leader Nichi Vendola, who said that his coalition would have to deal with Grillo, who mixes fierce attacks on corruption with policies ranging from clean energy to free Internet.