Four Frankfurt-based traders have won a case for wrongful dismissal against Deutsche Bank, which had accused them of violating company policy by inappropriately communicating with other traders at the bank.

"The termination was out of proportion," presiding judge Annika Gey told a Frankfurt labour court today.

Deutsche Bank had in February suspended five traders suspected of inappropriate conduct following an internal investigation into possible manipulation of the Europe Interbank Offered Rate (Euribor). Four of them - Ardalan G, Kai-Uwe K, Markus K, and Joerg V, whose full names are not being made public for legal reasons - appealed against their dismissal.

The traders worked in the money markets team at Deutsche Bank and were responsible for submitting the bank’s estimates for the Euribor and Swiss franc inter-bank offered rate to an international inter-bank lending poll.

According to judge Gey, Germany's flagship lender fired them in late February after it found chatroom and e-mail messages that showed inappropriate communications between them and other traders at the bank.

Deutsche Bank had argued that the traders who submitted estimates for inter-bank lending rates should have done so “totally objectively”. The traders, in suing Deutsche Bank, said they were not aware of a ban prohibiting them from talking to other trading desks about inter-bank lending matter.

Their lawyer, Peter Roelz, told the court that Deutsche Bank was aware of informal communication between derivatives and money market traders. Judge Gey said she found that there were no guidelines for interaction between those who submit the Euribor rates and traders on other teams.

Mr Roelz said he was satisfied with the court’s ruling, while Deutsche Bank’s lawyer said he would wait for the written judgment before deciding whether to lodge an appeal.