A former Barclays trader has been convicted of rigging a key euro benchmark borrowing rate known as Euribor.
Philippe Moryoussef has been found guilty of conspiracy to defraud by manipulating rates between 2005 and 2009.
The jury at Southwark Crown court has acquitted another defendant, Achim Kraemer, 51, who is still working for Deutsche Bank.
Christian Bittar, a former senior trader at Deutsche Bank, pleaded guilty in the 11-week trial began.
The determination of the penalty Moryoussef and Bittar is expected at the end of next week.
However, Moryoussef left the UK for France after Bittar guilty plea was made public. Therefore, it is difficult to know if or when he will serve time in jail.
His Paris-based lawyer, Francis De Casto said that his client was under the protection of French law, and would refer the case to the European Court of Human Rights.
The jury failed to reach a verdict on three other former Barclays co-defendants: Colin Bermingham, Carlo Palombo and Sisse Bohart.Review proceedings of the decision
During the trial, the accused have denied any dishonesty and said that they believed that they had done nothing wrong.
Criminal proceedings were instituted against six as a result of a Serious fraud Office (SFO) investigation into alleged manipulation of Euribor.
Based in Brussels the rates used to set trillions of dollars of financial contracts. It is a cousin of the BRITISH Libor is the average interest rate at which eurozone banks lend to each other.
The SFO has said that it would decide within seven days whether to ask for a new trial of three other accused.
A former Société Générale banker and four other Deutsche Bank employees have also been accused of conspiracy, but the united KINGDOM has been unable to get them extradited by France and Germany.
Although the authorities have fined major banks and brokerages around $9bn and charged about 30 people over rate rigging allegations, the SFO charge has been the first to focus on the Euribor.