Rome, February 7 - Troubled lender Monte dei Paschi di Siena (MPS) bank's chief executive on Thursday said there are no more high-risk derivatives operations on the bank's books. During a conference call, Fabrizio Viola said that "in a commercial bank like MPS, finance must have a residual role and in any case it must be functional to the bank's (main) activities". Viola was referring to the derivatives scandal at MPS which has shaken Italy's third-largest lender and scared off investors. On Wednesday MPS said that total losses from failed high-risk derivatives operations at the 541-year-old bank reached 730 million euros. During the conference call Thursday Viola said there were no other derivatives operations like Santorini - the complex operation which led to part of the bank's huge losses - on the banks books.