By Antonella Cinelli and Silvia Aloisi
ROME/SIENA (Reuters) - There was no evidence that Nomura <8604.T> made wrongful or disproportionate gains from its contentious "Alexandria" derivative deal with Italian bank Monte dei Paschi
The "Alexandria" deal is one of three trades at the heart of a criminal probe at Banca Monte dei Paschi di Siena, which booked losses of 730 million euros in 2012 after saying details of the complex derivatives deals had only just come to light.
But Judge Ugo Bellini on Friday rejected an order issued by prosecutors in Siena wanting to seize around 1.8 billion euros ($2.3 billion) of assets from Nomura <8604.T> as part of the probe.
In a document explaining his decision, the judge challenged a number of allegations made by the prosecutors, including one that Nomura had reaped abnormal gains from the "Alexandria" contract which it entered into with Monte Paschi in 2009.
"One cannot at this stage fail to observe the lack of any objective element to consider unjustified or disproportionate economic benefits for Nomura stemming from the overall transaction with Monte dei Paschi," he said in the document, reviewed by Reuters.
The Siena prosecutors plan to appeal against his ruling, according to judicial sources.
The seizure order, issued on April 15, was aimed at preventing Monte Paschi from putting up more cash with Nomura to meet the collateral requirements of the "Alexandria" trade.
The magistrates alleged Japan's largest broker colluded with former managers of Monte Paschi, the world's oldest bank, to conceal losses and set up huge hidden bets on Italian government bonds that helped drive the Italian bank close to collapse.
The prosecutors and current management at the Siena-based bank also allege that Nomura earned some 88 million euros in "hidden" fees from the deal.
Nomura says it has done nothing wrong and will defend itself vigorously against any allegation of wrongdoing.
The prosecutors said that as of April 5 the Tuscan bank had deposited 1.87 billion euros with Nomura as collateral under the deal.
Any additional payments due, temporarily frozen by the seizure order, have now resumed, a judicial source told Reuters.
Assets worth 140 million euros that had already been seized from the Japanese bank were released under the judge's latest ruling.
(Editing by Greg Mahlich)