Italian Premier Silvio Berlusconi said on Saturday the he will submit his resignation to President Carlo Azeglio Ciampi on Tuesday, Italian News Agency ANSA reported.

Berlusconi, who has not yet called Prodi to concede defeat in political election, said he would see Ciampi immediately after a cabinet meeting convened on Tuesday.

Italian center-left candidates Franco Marini and Fausto Bertinotti were elected Senate and Lower House Speakers on Saturday, clearing the way for the formation of a center-left government led by former European Commission president Romano Prodi.

Marini, a senator with the centrist Daisy party was elected on the fourth ballot, garnering 165 votes against the 156 votes cast by the center right for former premier Giulio Andreotti, a life senator.

But the center left's failure to get Marini elected on Friday highlighted the fragility of Prodi's hold on the Upper House as well as looming problems with coalition unity.

At least four senators initially broke rank, failing to back Marini in the first day of voting in the 322-seat house.

Prodi, who won a wafer-thin victory over outgoing premier Silvio Berlusconi in Italy's April 9 and 10 general election, had been hoping for a first-round election for Marini.

Marini's election, at the end of two controversial days of voting, was greeted by a long round of applause led by his 87-year-old opponent.

"I'm very, very, very happy. We've settled down now," said a jubilant premier-elect Prodi, whose Union coalition holds a two-seat majority in the Senate.

The Union needed the support of at least four of Italy's seven life senators and one independent from abroad to get Marini elected.

Earlier on Saturday, veteran Communist Fausto Bertinotti was elected House Speaker with an absolute majority of 337 votes. The Union has a 64-seat majority in the 630-seat chamber and Bertinotti 's election had not been in doubt, despite numerous votes for Democratic Left Chairman Massimo D'Alema.

Bertinotti - leader of the Communist Refoundation Party - was also elected on the fourth ballot, when a two-third majority was no longer required.

Both Marini and Bertinotti, former trade union leaders, pledged impartiality, saying in their acceptance speeches they would work to represent both coalitions' interests fairly.

But despite the upbeat climate in the center left, most political commentators agreed that the difficulty surrounding

Marini's election showed that the incoming government will need to close ranks if it hopes to survive in the Senate.

Italian newspaper "Corriere della Sera" (Evening's post) editorialist Paolo Franchi warned that the mishap over Marini's election was a sort of wake-up call for the coalition.

Under the Italian constitution, it is the president's job to formally appoint a new government. Ciampi's term ends on May 18 and the 85-year-old president has made it clear that he would like his successor - who will be chosen by the parliament in voting on May 11 and 12 - to name the new premier.

(Xinhua News Agency April 30, 2006)