Italian President Giorgio Napolitano will step down in hours, Prime Minister Matteo Renzi said today, opening up a delicate political process to name a new head of state.

The 89-year-old Napolitano, who reluctantly agreed to a second term in 2013 after a deadlocked election threatened to leave Italy politically adrift, said last month he would resign soon because of age-related ailments.

"I would like us to salute Napolitano, a committed Europeanist who in these hours will leave his post ... having led Italy with intelligence and wisdom," Renzi said in a speech to the European Parliament to mark the close of the EU semester.