The head of Italian defence firm Leonardo, Alessandro Profumo, was sentenced to six years in prison on Thursday for fraud related to when he headed the troubled lender Banca Monte dei Paschi di Siena (BMPS).

The court found Profumo guilty of market rigging and false accounting at BMPS in the first half of 2015, fined him 2.5 million euros ($3.1 million), and prohibited him from managing a company for two years.

The bank's former director-general Fabrizio Viola was sentenced to the same penalties, while BMPS itself was fined 800,000 euros.

Both men, who were additionally barred from public office for five years and from heading a company for two years, remain free pending an appeal.

Sources from their defence team told financial wire agency Radiocor the verdict would likely not have repercussions on Profumo's continued stewardship of Leonardo, given it is not final.

"We shall read carefully the reasons (for the verdict) and shall appeal the sentence which we find to be erroneous," said Adriano Raffaelli, representing Profumo and Viola.

"We are convinced our clients acted correctly," said Raffaelli.

Leonardo in a statement expressed its "full confidence in the actions of Profumo and wishes for his continuation in the role".

The former chairman of the bank's board of auditors, Paolo Salvadori, was sentenced to three-and-a-half years in jail for false communication.

The charges concerned irregularities in how two derivatives products called Alexandria and Santorini were registered in the bank's accounts.

The court found the statute of limitations had passed concerning charges relating to BMPS' 2012 financial results, and found no wrongdoing for 2013 and 2014.

Founded in Siena in 1472, BMPS ran into trouble during the eurozone debt crisis. 

Despite an EU-approved bailout of 5.4 billion euros of public money that made the Italian state its majority shareholder and heavy restructuring efforts, it has struggled to turn the corner from its troubles.