EU antitrust regulator imposed a fine totalling $390 million over rigging forex spot trading of G10 currencies.
EU antitrust regulators have fined Barclays, Credit Suisse, HSBC and NatWest a total of $390 million (344 million euros) for rigging the foreign exchange spot trading market.
HSBC's fine was the largest with $197.5 million, followed by Credit Suisse at $94.4 million, Barclays at $61,5 million and RBS at $36.8 million.
The EU competition regulator said on Thursday the cartel had focused on forex spot trading of G10 currencies.
The traders involved exchanged sensitive information and trading plans and occasionally coordinated their trading strategies via the chatroom on whether and when to sell or buy the currencies in their portfolios, the Commission said.
"Today we complete our sixth cartel investigation in the financial sector since 2013 and conclude the third leg of our investigation into the foreign exchange spot trading market," EU antitrust chief Margrethe Vestager said.
UBS, on the other hand, avoided a $106 million fine as it had alerted the European Commission about the cartel, which was set up via a chatroom known as "Sterling Lads".
"This is a legacy matter where UBS was the first bank to disclose potential misconduct and we are pleased the matter is resolved." UBS said.
Barclays, HSBC and RBS admitted wrongdoing in return for a cut in the penalty. RBS is now known as NatWest following a rebranding last year.
Credit Suisse, Barclays and HSBC declined to comment while NatWest said the misconduct took place in a single chatroom and involved a former employee about a decade ago and that its culture and controls have changed fundamentally during the past ten years.