Italy's lawmakers failed to elect a new president on Monday as a split between Romano Prodi's left and Silvio Berlusconi's right produced a stalemate in the first round of voting for the next head of state.

Montecitorio Hall during the vote for the new head of state at the Italian Parliament, in Rome, May 8, 2006. [Reuters]

No candidate secured the two-thirds majority required to elect the president in the first three rounds of voting.

"We need to proceed to a second round of voting," lower house speaker Fausto Bertinotti said.

The inconclusive vote means that Italy's 1,010 "grand electors" will convene again on Tuesday to try to elect a president but voting could go on until Wednesday and beyond if Italy's divided political class fails to agree on a name.

Although Italy's president has a largely ceremonial role, finding a replacement for Carlo Azeglio Ciampi, whose seven-year term expires this month, comes at a crucial moment as Prodi can not take office until the new leader gives him a formal mandate.

Prodi tried but failed to persuade the center right -- which he narrowly beat in April's election -- to vote for his candidate, 80-year-old life senator Giorgio Napolitano, of the Democrats of the Left (DS), the biggest party in his bloc.

But shortly before the lawmakers went into booths in parliament to cast their secret ballots, Berlusconi said his center-right bloc would vote for his close aide Gianni Letta.

Letta got the most votes in the election with 369, but 438 ballots were left blank. The two-thirds majority is 674 votes.

Earlier in the day, as it became clear that Napolitano would not secure a two-thirds majority, Prodi told center-left lawmakers to post blank ballots rather than write the candidate's name which would have tainted him with defeat.

Several lawmakers made mischievous or protest votes, writing names of notable prisoners, a famous singer and even Berlusconi himself.

Prodi said the center left had decided on the blank ballot tactic while it waited for more signals from the center right on the possibility of agreeing on a candidate in the second or third rounds which will take place on Tuesday.

But when asked if the election would succeed on Tuesday, Berlusconi told reporters: "I don't think that's possible."

By the fourth round, which would happen on Wednesday if the stalemate continues, a simple majority is sufficient, meaning Prodi may be able to push his candidate through against the opposition's wishes.

But that would only increase the bitterness between the two camps and could make it harder for Prodi to carry through his policy program once in government.

Whether Napolitano, a former interior minister and parliamentary speaker, remains the center left's candidate is uncertain.

Members of DS, the biggest party in Prodi's coalition, initially wanted its chairman, the 57-year-old former prime minister Massimo D'Alema, elected to the country's top job, but he was rejected by the center right as being too partisan.

Some analysts have suggested that Prodi only put forward Napolitano as a kind of "stalking horse," intending to revert to proposing D'Alema if Napolitano does not get broad backing.

On Sunday, Berlusconi's allies put forward four names they would like to see as candidates, none of them from the DS: former prime ministers Giuliano Amato and Lamberto Dini, former European Commissioner Mario Monti and Senate speaker Franco Marini.

Whereas outgoing President Ciampi enjoys cross-party support and was elected in the first round seven years ago, it took 13 days to elect his predecessor in 1992.