The re-election of President Giorgio Napolitano provoked gratitude from the mainstream Italian parties and protests from followers of the anti-establishment 5-Star Movement (M5S), ANSA reported.

Most of the parties in parliament lobbied Napolitano to agree to serve a second term and end a situation of gridlock after five ballots failed to elect a successor to the 87-year-old because of rifts within the centre-left Democratic Party (PD), the biggest group in parliament. The deadlock was threatening to further complicate efforts to end the political impasse recession-hit Italy has endured since February's inconclusive general election.

Ex-premier Silvio Berlusconi, whose centre-right alliance came second in February, thanked Napolitano for his "spirit of sacrifice" and "personal generosity" for agreeing to serve a second term as Italy's head of state "in such a difficult, uncertain situation".

Outgoing PD leader Pier Luigi Bersani said the re-election was "excellent" and outgoing Premier Mario Monti expressed satisfaction too.

But there was tension outside Italy's Lower House of parliament, where a big crowd gathered after M5S leader Beppe Grillo urged "millions" to protest against the re-election.