Six defendants, including ex-Deutsche Bank trader Christian Bittar, pleaded not guilty to accusations of conspiring to manipulate a key interest-rate benchmark while working at the German lender and Barclays in a London court.

Bittar, one-time colleague Achim Kraemer, and ex-Barclays employees Philippe Moryoussef, Colin Bermingham, Carlo Palombo and Sisse Bohart all denied the charges on Tuesday.

They’re accused of conspiring with other bank employees between 1 January, 2005, and 31 December, 2009, to "procure or make submissions" in relation to the euro interbank offered rate, known as Euribor, that were false.

The six are among 11 traders charged in the case and are scheduled to stand trial in September. They are the first to face charges globally in relation to Euribor, the euro counterpart of the London interbank offered rate, or Libor.

A number of individuals have faced prosecution over Libor rigging. The other five defendants in the Euribor case worked at Deutsche Bank and Societe Generale and live in Germany and France. The Serious Fraud Office issued warrants for their arrest last year.