Global regulators have announced $US3.2 billion ($A3.46 billion) in fines against five major US and European banks over allegations of rigging in foreign exchange markets.
The hefty fines, announced in London, Washington and Zurich, follow a worldwide probe into the scandal surrounding the forex market.
British banks HSBC and Royal Bank of Scotland, US groups Citibank and JPMorgan Chase, and Swiss bank UBS have all been fined by Britain's Financial Conduct Authority and the US Commodity Futures Trading Commission, the pair said in a statement.
The FCA hit the five banking giants with a total penalty of STG1.1 billion ($A2 billion), while the CFTC has fined them $US1.4 billion ($A1.5 billion) over the same matter.
In addition, the Swiss Financial Market Supervisory Authority announced a $139-million settlement with UBS.
"The failings at these banks undermine confidence in the UK financial system and put its integrity at risk" Britain's FCA said in a statement.
British lender Barclays was not included in the settlements but the bank added separately that it continued to hold talks with regulators.
The FCA said that, between January 1, 2008 and October 15, 2013, it found that "ineffective controls" at the five banks allowed their foreign exchange traders "to put their banks' interests ahead of those of their clients, other market participants and the wider UK financial system".
It added that the banks "failed to manage obvious risks around confidentiality, conflicts of interest and trading conduct".
The total FCA fine is a record amount and eclipses the STG532 million ($A971 million) penalty it handed down to banks and brokers over the 2012 Libor interbank rate-rigging scandal.
The US CFTC announced in a separate statement that the five banks were being punished for "attempted manipulation of, and for aiding and abetting other banks' attempts to manipulate, global foreign exchange benchmark rates to benefit the positions of certain traders."
