Japanese bank Nomura <8604.T> is seeking to establish British jurisdiction for its dispute with Monte dei Paschi di Siena over risky derivatives trades, a source close to the matter said on Monday.
Nomura began proceedings in Britain's High Court on March 1, the same day that Italy's scandal-hit Monte dei Paschi filed a damages claim in a Florence court, the source said, speaking on condition of anonymity.
The source added that Nomura is asking the court to declare that the "contracts are valid", a move aimed at ensuring that any legal dispute will be settled in London rather than Italy.
Both Nomura and Monte dei Paschi declined to comment.
The Italian bank, which is at the centre of a probe into alleged corruption and fraud, is seeking at least 700 million euros (610 million pounds) in damages from Nomura and two former Monte dei Paschi executives, a judicial source told Reuters last week.
Monte dei Paschi, the world's oldest bank and Italy's third-biggest, is also seeking damages of at least 500 million euros from Deutsche Bank and the same former managers over a separate derivatives deal.
Italian prosecutors say that the derivative trades with Nomura and Deutsche Bank were not fully disclosed to regulators by former Monte dei Paschi executives as they sought to conceal losses.
The bank in February put total losses from those two deals and one other at 730 million euros relative to its 2012 net assets.
(Reporting By Silvia Aloisi; Editing by David Goodman)