Bittar's plea had been subject to reporting restrictions, but these were lifted on Thursday. Five co-defendants will still face a jury at London's Southwark Crown Court from April 9. They are charged with one count of conspiracy to defraud.

"It would not be right to make comment prior to the trial of the remaining defendants and prior to Mr Bittar's sentencing," said David Savell of Locke Lord, who is representing Bittar.

Deutsche Bank declined to comment.

It will be the fifth time the SFO prosecutes former traders on charges relating to benchmark rate manipulation. Five men have been jailed and eight acquitted to date in a near six-year criminal investigation that underscores the complexity of bringing white collar crime cases.

Euribor, the euro interbank offered rate, is the Brussels-based equivalent of London-based Libor. Four other men and one woman have pleaded not guilty to one count of conspiracy to defraud by manipulating Euribor between 2005 and 2009.

The SFO originally planned to charge 11 Deutsche Bank, Barclays and Societe Generale traders in the case. But five men from Germany and France did not attend a London court hearing to be formally charged in 2016 and they have not been subsequently extradited.

Bittar, once one of Deutsche Bank's most profitable bankers, worked in London as a senior trader in interest rate-based derivatives before moving to Singapore in 2010. He left the bank in 2011.

A separate case against him by Britain's markets watchdog, the Financial Conduct Authority (FCA), has been put on hold pending the criminal proceedings.

Designed to estimate the costs at which banks will lend to each other, benchmark rates such as Libor and Euribor are central cogs in the global financial system and a benchmark for interest rates on an estimated $450 trillion (322.9 trillion) of financial contracts, from derivatives to student loans.

Since a global investigation into benchmark rigging was sparked by U.S. regulators in 2008, financial institutions have paid around $9.0 billion to settle regulatory allegations of rate rigging and around 30 individuals have been charged.

Deutsche Bank was fined $2.5 billion by U.S. and British authorities in 2015 as part of that investigation.

(Additional reporting by Arno Schuetze in Frankfurt; Editing by Mark Potter)

By Kirstin Ridley

Stocks treated in this article : Société Générale, Deutsche Bank, Barclays