Rome, Dec 9 (IANS): Italian President Sergio Mattarella and party leaders have started talks over how to form a transitional government after Prime Minister Matteo Renzi resigned on Wednesday.

Renzi's resignation followed defeat in the December 3 referendum on constitutional reform law, Xinhua news agency reported.

The talks which started on Thursday are expected to end by Saturday, according to the President's office.

Mattarella has asked the Renzi government to remain in charge of day-to-day business while he launches consultations with the country's main political forces in an effort to lead the country out of the impasse to form the interim government.

In a brief address on Wednesday to the executive of his centre-left Democratic Party, Renzi said the future holds two alternatives -- either a broad coalition government to steer the country through the end of the current legislature in 2018 or early elections as soon as the Constitutional Court pronounces itself on "Italicum" electoral law.