A court sitting in London said Philippe Moryoussef, a former Barclays derivatives trader has been found guilty of conspiracy to defraud by dishonestly manipulating Euribor.
Euribor is the Euro interbank offered rate.
Philippe Moryoussef who was tried in absentia was found to have committed the offense between January 2005 and December 2009 after an 11-week trial.
According to Reuters News, the jury at Southwark Crown Court acquitted Achim Kraemer, a Deutsche Bank manager still employed by the bank.
The jury were unable to reach a verdict on the other three traders on trial.