Maria Elisabetta Casellati, a confidante of former prime minister Silvio Berlusconi and incumbent president of the Senate, received the most votes: 382 of the 1009 parliamentarians and regional representatives backed her.

However, she was far off the absolute majority of 505 votes required to become Italy's first female president.

The Lega of former interior minister Matteo Salvini and Berlusconi's Forza Italia were among the parties that had leant their support to Casellati prior to the ballot.

As anger among the public grew over the protracted elections, the parties decided in the morning to hold two votes a day from now on.

A sixth round is scheduled to begin at 5pm on Friday.

In the fifth round, 406 representatives abstained from voting.

Of the 530 votes cast, 46 went to the incumbent President Sergio Mattarella.

However, he is not thought to be seeking a second term in office.

Votes also went to Prime Minister Mario Draghi and Justice Minister Marta Cartabia.

The president's seven-year term is mostly filled with ceremonial matters.

The job at times can wield big power, including by halting legislation, dissolving parliament and thus initiating new elections, and approving or preventing the appointment of ministers.

Australian Associated Press