Shareholders of the world's oldest bank have approved a plan needed to get a state bailout amid revelations that it concealed loss-making risky trades.
Italy's Banca Monte dei Paschi di Siena and regulators are investigating the trades.
The Bank of Italy defended its role in supervising Italian banks, denying knowledge of the trades.
Banca Monte needs 3.9bn euros (£3.3bn, $5.2bn) in government aid to meet European banking rules.
The Tuscan bank, founded in 1472, confirmed this week that the three trades - named Alexandria, Santorini and Nota Italia - would be investigated in full to "precisely assess the impact of the transactions and consequently adopt any measures needed, including a retrospective restatement of their accounting representation".
Reports have suggested the trades could lead to another 720m euros of losses.
This has raised the prospect of further losses, and the trades are being investigated by regulators. Banca Monte plans to report on its internal investigation into the trades by mid-February.
Italian Prime Minister Mario Monti has offered to recall parliament to discuss the growing scandal and President Giorgio Napolitano said that he had full faith in the country's central bank.
BBC News - Banca Monte dei Paschi trades probed in Italy
