ROME (Reuters) - The Italian stock market fell and state borrowing costs rose on Tuesday as investors took fright at political deadlock after a stunning election that saw a comedian's protest party lead the poll and no group secure a clear majority in parliament.
"The winner is: Ingovernability" ran the headline in Rome newspaper Il Messaggero, reflecting the stalemate the country would have to confront in the next few weeks as sworn enemies would be forced to work together to form a government.
In a sign of where that might lead, former prime minister Silvio Berlusconi indicated his center-right might be open to a grand coalition with the center-left bloc of Pier Luigi Bersani, which will have a majority in the lower house thanks to a premium of seats given to the largest bloc in the chamber.
Results in the upper house, the Senate, where seats are awarded on a region-by-region basis, indicated the center-left would end up with about 119 seats, compared with 117 for the center-right. But 158 are needed for a majority to govern.
Any coalition administration that may be formed must have a working majority in both houses in order to pass legislation.
Comedian Beppe Grillo's anti-establishment 5-Star Movement won the most votes of any single party, taking 25 percent. He shows no immediate inclination to cooperate with other groups.
Despite talk of a new election, the main established parties seem likely to try to avoid that, fearing even more humiliation.
World financial markets reacted nervously to the prospect of a stalemate in the euro zone's third largest economy with memories still fresh of the crisis that took the 17-member currency bloc to the brink of collapse in 2011.
In a clear sign of worry at the top over what effect the elections could have on the economy, Prime Minister Mario Monti, whose austerity policies were repudiated by voters, called a meeting with the governor of the central bank, the economy minister and the European affairs minister for later on Tuesday.
Other governments in the euro zone sounded uneasy. Allies of German Chancellor Angela Merkel made no secret of disappointment at Monti's debacle and urged Rome to continue with economic reforms Berlin sees as vital to stabilizing the common currency.
France's Socialist finance minister also expressed "worry" at the prospect of legislative deadlock in Italy but said that Italians had rejected austerity and hoped Bersani's center-left could form a stable government to help foster growth in Europe.
INSTABILITY
Fabio Fois, an economist at Barclays bank, said: "Political instability is likely to prevail in the near term and slow the implementation of much needed structural reforms unless a grand coalition among center-left, center-right and center is formed."
Berlusconi, a media magnate whose campaigning all but wiped out Bersani's once commanding opinion poll lead, hinted in a telephone call to a morning television show that he would be open to a deal with the center-left - but not with Monti, the technocrat summoned to replace him in a crisis 15 months ago.
"Italy must be governed," Berlusconi said, adding that he "must reflect" on a possible deal with the center-left. "Everyone must be prepared to make sacrifices," he said of the groups which now have a share of the legislature.
The Milan bourse was down more than four percent and the premium Italy pays over Germany to borrow on 10-year widened to a yield spread of 338.7 basis points, the highest since December 10.
At an auction of six-month Treasury bills, the government's borrowing costs shot up by more than two thirds. Investors demanded a yield of 1.237 percent, the highest since October and compared to just 0.730 percent in a similar sale a month ago.
Berlusconi, who was forced from office in November 2011 as borrowing costs approached levels investors feared would become unsustainable, said he was "not worried" about market reaction to the election and played down the significance of the spread.
The poor showing by Monti's centrist bloc reflected a weariness with austerity that was exploited by both Berlusconi and Grillo; only with the help of center-left allies did Bersani beat 5-Star, by just 125,000 votes, to control the lower house.
The worries immediately went beyond Italy's borders.
"What is crucial now is that a stable functioning government can be built as swiftly as possible," said German Foreign Minister Guido Westerwelle. "This is not only in the interests of Italy but in the interests of all Europe."
The euro skidded to an almost seven-week low against the dollar in Asia on fears about the euro zone's debt crisis. It fell as far as $1.3042, its lowest since January 10.
"NON-PARTY" SURGES TO THE TOP
Commentators said all Grillo's adversaries underestimated the appeal of a grassroots movement that called itself a "non-party", particularly its allure among young Italians who find themselves without jobs and the prospect of a decent future.
The 5-star Movement's 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 'non-party' has become the largest party in the country," said Massimo Giannini, commentator for Rome newspaper La Repubblica, of Grillo, who mixes fierce attacks on corruption with policies ranging from clean energy to free Internet.
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.
RECESSION
"It's a classic result. Typically Italian," said Roberta Federica, a 36-year-old office worker in Rome. "It means the country is not united. It is an expression of a country that does not work. I knew this would happen."
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 of many European countries that it would not produce a government strong enough to implement effective reforms.
A long recession and growing disillusionment with mainstream parties fed a bitter public mood that saw more than half of Italian voters back parties that rejected the austerity policies pursued by Monti with the backing of Italy's European partners.
Monti suffered a major setback. His centrist grouping won only 10.6 percent and two of his key centrist allies, Pier Ferdinando Casini and lower house speaker Gianfranco Fini, both of parliamentarians for decades, were booted out.
"It's not that surprising if you consider how much people were let down by politics in its traditional forms," Monti said.
Berlusconi's campaign, mixing sweeping tax cut pledges with relentless attacks on Monti and Merkel, echoed many of the themes pushed by Grillo and underlined the increasingly angry mood of the Italian electorate.
Even if the next government turns away from the tax hikes and spending cuts brought in by Monti, it will struggle to revive an economy that has scarcely grown in two decades.
Monti was widely credited with tightening Italy's public finances and restoring its international credibility after the scandal-plagued Berlusconi, who is currently on trial for having sex with an under-age prostitute.
But Monti struggled to pass the kind of structural reforms needed to improve competitiveness and lay the foundations for a return to economic growth, and a weak center-left government may not find it any easier.
(Additional reporting by Barry Moody, Gavin Jones, Catherine Hornby, Lisa Jucca, Steven Jewkes, Steve Scherer and Naomi O'Leary; Writing by Philip Pullella; Editing by Alastair Macdonald)