The Italian president began talks with political leaders Thursday to discuss forming a new government after the resignation of Premier Romano Prodi's nine-month-old administration.

Prodi stepped down Wednesday evening after an embarrassing parliamentary defeat of his government's proposed foreign policy program, including its plan to keep Italian troops in Afghanistan. He is staying on in a caretaker role.

The consultations at the presidential palace are aimed at determining which political leaders, if any, might be able to muster enough support for a parliamentary majority and thus avoid a new election.

President Giorgio Napolitano might ask Prodi or another leader from his coalition to form a new center-left government. He also could ask an institutional figure above the political fray to form a government, possibly with broad support from both coalitions, or he could call elections.

Napolitano started by meeting with Senate speaker Franco Marini, who is considered a possible leader for an institutional government. The speaker of the lower house of parliament, party leaders and former presidents were to follow in the talks, expected to continue through Friday.

Many observers say that Napolitano would be unlikely to call elections so far ahead of the next scheduled vote in 2011. Many political leaders also want to change the current proportional representation system that is seen as encouraging small parties and leading to instability.

The premier's aides did not rule out the possibility that Napolitano would ask Prodi to form another government, and from first discussions among some allies, support for another Prodi government seemed to be building.

"Prodi is willing to stay if, and only if, he will receive guarantees of full support from all coalition parties," said the premier's spokesman, Silvio Sircana.

But with a Senate he cannot fully control and a diverse coalition, any new Prodi government supported by the same forces would be dogged by instability. To avert the risk, some center-left party leaders were looking to centrist lawmakers who have left the conservative bloc led by former Premier Silvio Berlusconi.

"Giving Prodi a new mandate is the obvious way to go, but it is an insidious one. It's necessary to avoid the same mistakes and contradictions that have led to this downfall," said Stefano Folli, a leading analyst.

Prodi's resignation after the closest election in Italy's postwar history raised fears that the years of "revolving-doors" governments were back. Italy has had relative political stability in the past decade, with Berlusconi remaining in power five years despite some Cabinet shuffles.

Berlusconi wants early elections or a broad coalition government.

"I don't think there are any senators in this parliament willing to jump onto a sinking ship," he said.

On Wednesday, the government lost a motion in the Senate supporting the government's foreign policy, including maintaining a military presence in Afghanistan, by just two votes. The vote was not binding, but it signaled that Prodi did not muster command of the upper chamber on key policies, leading the premier to resign.