Troubled Italian bank Monte dei Paschi di Siena is seeking damages from two former executives and investment banks Nomura <8604.T> and Deutsche Bank over derivatives trades losses.
The Tuscan bank, Italy's third-biggest, suffered losses of around 730 million euros ($954 million) from a number of structured finance deals carried out under former Chairman Giuseppe Mussari and former Director General Antonio Vigni.
The two most problematic trades are a restructuring of notes called Alexandria, which was carried out with Nomura in 2009, and the restructuring of a vehicle known as Santorini carried out with Deutsche Bank at the end of 2008.
Monte dei Paschi said it had launched the legal action with the civil court in the Tuscan city of Florence on Friday.
The world's oldest bank, Monte dei Paschi has been at the centre of a financial and political storm that has raised questions about the role of banking supervisors and also local politicians in the run-up to elections last week.
The bank aid on Thursday it had received a four billion euro state bailout needed to boost its capital base.
Mussari and Vigni have already been placed under investigation by prosectuors examining the bank's affairs.
($1 = 0.7649 euros)
(Reporting By Lisa Jucca; editing by Keith Weir)