Italy's Monte dei Paschi di Siena is seeking damages of at least 1.2 billion euros (1.03 billion pounds) from two former executives and investment banks Nomura <8604.T> and Deutsche Bank over derivative trades, a judicial source with direct knowledge of the matter told Reuters.

The Tuscan bank, Italy's third-biggest, suffered losses of around 730 million euros from a number of structured finance deals carried out under former Chairman Giuseppe Mussari and former Director General Antonio Vigni.

It said last week it was seeking damages from Vigni, Mussari, Nomura and Deutsche Bank over the two costliest trades, without giving further details.

The source said the bank was seeking "at least 700 million euros" from Vigni, Mussari and Nomura for a 2009 structured deal known as Alexandria.

In addition, it was seeking "at least 500 million euros" from the same two former executives and Deutsche Bank for a 2008 deal known as Santorini.

Monte dei Paschi, Nomura and Vigni's lawyer declined to comment. Deutsche Bank and Mussari's lawyer were not immediately available for comment.

(Reporting By Silvia Ognibene and Stefano Bernabei; Writing by Silvia Aloisi; editing by Elaine Hardcastle)