The European Commission said Wednesday it levied a record fine of 1.71 billion euros ($2.3 billion) on five major global banks and a London-based broker for allegedly colluding to set interbank Euribor, Libor and Tibor interest rates.

The financial institutions hit with the penalties were Deutsche Bank, Societe Generale, Royal Bank of Scotland, JPMorgan, Citigroup, and broker RP Martin Holdings, Competition Commissioner Joaquin Almunia told a press conference.

Barclays and UBS, which had already been slapped with fines by U.S. and British regulators, avoided additional penalties by revealing the existence of the cartels in the market for derivative products, financial agreements whose value is derived from the level of an underlying asset, index or benchmark interest rate.

Seven banks allegedly participated in illegal cartels to manipulate the Euro Interbank Offered Rate, or Euribor.

Four of them - Barclays, Deutsche Bank, RBS and Societe Generale - settled with the EC.

HSBC, Credit Agricole and JPMorgan are contesting the allegations.

UBS, RBS, Deutsche Bank, JPMorgan, Citigroup and RP Martin settled a case for collusion in the Yen interest rate derivatives sector, including discussions between traders on certain Yen-denominated London Interbank Offered Rate, or Libor, submissions and one infringement related to certain future Euroyen Tokyo Interbank Offered Rate, or Tibor, submissions.

The fines amounted to the largest combined penalty handed down by European antitrust regulators.

"What is shocking about the Libor and Euribor scandals is not only the manipulation of benchmarks, which is being tackled by financial regulators worldwide, but also the collusion between banks who are supposed to be competing with each other," Almunia was quoted as saying in an EC press release.

Wednesday's decision "sends a clear message that the Commission is determined to fight and sanction these cartels in the financial sector," the competition commissioner added. EFE