ROME, May 9 (Xinhua) -- The Italian Parliament held a second day of voting on Tuesday to elect a successor to the outgoing President Carlo Azeglio Ciampi, after the first ballot on Monday failed to elect Italy's 11th post-war head of state.

    Over 1,000 delegates, consisting of 630 MPs, 322 Senators and 58 representatives from Italy's 20 regions, convened in the Chamber of Deputies for the secret-ballot vote.

    The incoming government of Romano Prodi has nominated the ex-interior minister and life Senator Giorgio Napolitano for the presidency. If elected, Napolitano would be the first ex-Communist in Italy's highest institutional post.

    However the result of the first of the day's two voting rounds was almost certain to be inconclusive as the central-left and the center-right blocs had not yet agreed on a candidate.

    Prodi's center-left Union coalition said on Tuesday it would cast blank votes on the second round of balloting as it had a day earlier, noting it would use the tactic to force outgoing Premier Silvio Berlusconi's forces to back Napolitano, local reports said.

    The center left's strategy is to avoid writing Napolitano's name in ballots until it is sure he has a good chance of winning.

    "This signifies a strong support for Napolitano's candidacy," Prodi told reporters a few hours before the second vote. "Let's hope for an agreement in the not too distant future," he added.

    Reports said center-right lawmakers might be persuaded to back Napolitano in the third round of voting, however, the center-right coalition did not seem ready to compromise.

    Napolitano, who turns 81 next month, needs a two-thirds majority of 674 in any of the first three votes for the presidency. Afterwards a simple majority of 506 is enough.

    Before becoming a life Senator last year, Napolitano was head of international relations for the Democratic Left and interior minister in the 1996-2000 Prodi government.

    Under the Italian Constitution, the president is the impartial guarantor of the Constitution and the titular head of the Council of Magistrates, the judiciary's self-governing body.

Backgrounder: Italy's election of new president 

    ROME, May 9 (Xinhua) -- Italy's parliamentarians and representatives of the country's 20 regions gathered here on Tuesday to elect the country's new president.

    The current head of state, Carlo Azeglio Ciampi, 85, has turned down appeals to stay on for a second term, citing his age. His seven-year mandate expires on May 18.

    Following is an explanation of the election procedures and the role of the president.     

    WHO ELECTS THE PRESIDENT?

    The president is elected in a joint session by the 630 members of the Lower House of the parliament, the 322 members of the Senate (including seven life senators) plus 58 regional delegates. Each region appoints three delegates, two representing the majority parties and one the opposition parties. The exception is Valle d'Aosta which has only one delegate.     

    VOTING PROCEDURES

    The 1,010 "grand electors," gather in the Lower House to vote. The Lower House speaker presides over the secret voting with the Senate speaker at his side. By tradition, the senators vote first, followed by the deputies and then the regional delegates.

    Each voter is required to step into either of the two booths located under the speaker's rostrum and write out in full the name of his or her chosen candidate.

    It may take a number of ballots for a winner to emerge.

    Under the Constitution, a two-thirds majority of 674 votes is required for a candidate to be elected on the first, second or third ballots. After that, an absolute majority of 506 votes is required.

    The first round of voting was held on Monday and the other two rounds will be on Tuesday. If possible, the application of the absolute majority rule will begin on Wednesday.

    In theory, the incoming center-left government of Romano Prodi can count on 541 votes compared to 460 for the opposition led by outgoing Prime Minister Silvio Berlusconi.

    Ciampi was elected president in 1999 on a first ballot in an unusual show of unity, receiving 707 votes out of a possible 990. But it took 13 days to elect his predecessor Oscar Luigi Scalfaro in 1992 with 16 rounds of voting.

    Only two other presidents apart from Ciampi were elected in one bout of voting: Enrico De Nicola, Italy's first president who was elected in 1946; and Christian Democrat Francesco Cossiga, elected in 1985.

    The most ballots occurred in 1971 when it took 16 days and 23 rounds of voting to elect Christian Democrat Giovanni Leone as the head of state.     

    ROLE AND POWERS OF THE PRESIDENT

    Under Italy's 1948 Constitution, the president must be over 50 and serves a seven-year mandate. The Senate Speaker acts as deputy president.

    Regarded as the impartial guarantor of the Constitution, the president is meant to be above the party fray and represent national unity. He is the titular head of the Council of Magistrates (CSM), the judiciary's self-governing body, and the head of the armed forces.

    In practice, he has limited powers, holding no veto over legislation and playing no role in foreign policy. But it is his task to give the winner of Italy's elections the mandate to govern. He also has the power to dissolve parliament, after consultations with the Lower House and Senate speakers, except during the last six months of his term.

    The president must sign parliamentary bills into law. He can send laws back to parliament if he thinks they are unconstitutional or lacking the necessary financial cover. He may only do this once, after the parliament passes the law.

    The president is entitled to appoint five new life senators during his mandate. He ratifies international treaties on the authorization of the Lower House and has the power to grant pardons.

    Berlusconi's outgoing government passed a sweeping constitutional reform trimming the powers of the president and increasing those of the prime minister. The reforms will be put to a referendum in June since they did not gain two-thirds support in parliament. The center-left wants them overturned.     

    CANDIDATES

    The center-left's candidate is Giorgio Napolitano, an 80-year-old life senator and former Communist. Napolitano once served as interior minister and House Speaker. Berlusconi had rejected his candidacy, saying his membership of the former Italian Communist Party (PCI) made him unacceptable.

    Berlusconi had also rejected the center-left's original candidate, former prime minister Massimo D'Alema, on the same grounds. D'Alema, who served as the prime minister from 1998-2000, is currently the chairman of the Democratic Left, the largest center-left party.

    Berlusconi wanted to press for his own candidate, outgoing premiership secretary and seasoned political mediator Gianni Letta-- Berlusconi's close aide and former deputy chairman of the Berlusconi family holding company Fin invest.

    The center-right had presented a compromise list of four candidates: ex-Socialist prime minister Giuliano Amato, ex-prime minister Lamberto Dini, newly elected Senate Speaker Franco Marini, and former European anti-trust commissioner Mario Monti. Enditem