ROME (Reuters) - Former Italian Prime Minister Silvio Berlusconi hinted on Saturday that he may seek to run in spring elections, changing his mind again and deepening chaos in his center-right party.

A day before the center-left is due to hold primary elections to pick a candidate to lead their alliance in the national poll, the center-right is still unsure about whether to hold its own primary vote, which hinges on Berlusconi's plans.

Asked by reporters on Saturday whether he was considering "returning to the playing field", Berlusconi said, "I am thinking about it."

Italy will hold a parliamentary election in March next year to pick a government and new leader to take over from Mario Monti, who came to power a year ago when Berlusconi stepped aside at the height of the financial crisis.

After months of hinting that he may run and then backtracking, Berlusconi said at the end of October that he would not lead his People of Freedom (PDL) party in the elections.

The center-right has been preparing to hold its own primary vote on December 16 to choose a new leader, but PDL secretary Angelino Alfano said on Saturday that "would not make much sense" if Berlusconi decides to stand himself.

The PDL has been close to disintegration due to disputes over whether to stick with Monti's unpopular economic policies. The party has slumped in opinion polls to less than half its support in 2008 elections, and speculation has been growing that Berlusconi may form his own breakaway party.

(Reporting By Catherine Hornby; Editing by Myra MacDonald)