Royal Bank of Scotland is among 20 banks to have been criticised by regulators in Singapore for attempting to manipulating key borrowing and currency rates.
The Monetary Authority of Singapore (MAS) said a total of 133 traders across banks such as Barclays, BNP Paribas and RBS “engaged in several attempts to inappropriately influence benchmarks”, although there was no conclusive evidence that they had been successful.
None of the banks have been fined, but ING, RBS and UBS have each been ordered to set aside between £510 million and £611m in additional reserves for a year. Barclays has been told to set aside between £204m and £306m.
The MAS, which is to make rate-rigging a criminal offence, said the groups caught up in its probe will also have to give quarterly updates on the steps they are taking to “address their deficiencies”.
Of the 133 traders found to have acted inappropriately, about three quarters had either been fired or resigned. The remainder will be subject to disciplinary action, including forfeiting their bonuses.
RBS has already been fined £390m by regulators in the UK and US for its part in rigging the London interbank offered rate (Libor), while Barclays paid a £290m penalty.
A spokesman for RBS, which is searching for a new chief executive following this week’s resignation of Stephen Hester, said the group “has co-operated fully with MAS on its review of benchmark submissions and will comply with any required regulatory, capital and remedial measures”.