Italy's parliamentary elections have ended in stalemate and the possibility of a hung parliament.
With all domestic votes counted, Pier Luigi Bersani's centre-left bloc won the lower house vote but has failed to secure a majority in the Senate.
News of the results led to a sharp fall on Italian financial markets.
Mr Berlusconi conceded the lower house vote but control of both houses is needed to govern. A protest movement led by comedian Beppe Grillo won 25%.