The Commission handed JPMorgan a 61.7-million-euro fine for rigging the Swiss franc Libor benchmark interest rate between March 2008 and July 2009. It was also fined 10.5 million euros for participating in a cartel on Swiss franc interest rate derivatives.

UBS' penalty in the derivatives cartel came to 12.7 million euros and that of Credit Suisse was 9.2 million euros. Royal Bank of Scotland alerted the Commission about both cartels and escaped total fines of 115 million euros.

The penalties are the latest by the European Commission, which along with authorities around the world, has handed down billions of euros in fines against top banks for rate-rigging, breaking trade sanctions and other misbehaviour.

"Acting against financial cartels is one of our top priorities, given the importance of a healthy, transparent, well-functioning financial sector for the entire economy," European Competition Commissioner Joaquin Almunia said.

The EU competition watchdog said the banks in the interest rate derivatives cartel agreed to collectively fix a pricing element which should have been determined by the market, between May and September 2007 with the aim of preventing rivals from competing on the same terms.

All the banks admitted wrongdoing in return for a 10 percent reduction in their fines.

The Commission slapped a record 1.7-billion-euro fine on six financial institutions last December for rigging two financial benchmarks.

(Reporting by Foo Yun Chee; editing by Barbara Lewis and Susan Thomas)

By Foo Yun Chee