BRUSSELS (AP) — European Union regulators on Wednesday fined banks JPMorgan Chase, HSBC and Credit Agricole a combined $520 million for colluding to manipulate the price of financial products linked to interest rates.

EU antitrust Commissioner Margrethe Vestager said the banks illegally exchanged sensitive information and colluded to make big profits in the market on the specialized financial products.

JPMorgan Chase was fined 337 million euros, France's Credit Agricole 114 million euros and London-based HSBC 33 million euros.

Three years ago, the antitrust regulators levied about a billion euros in penalties from Barclays, Deutsche Bank, RBS and Societe Generale as part of the same case, which covers manipulation of financial contracts linked to a benchmark interest rate called Euribor in the period 2005-2008. Those banks chose to settle, while Wednesday's decision sought to punish the three holdouts.

"This sends a clear message that banks, like all companies, have to respect EU competition rules," said Vestager. "Financial markets need to be competitive."

Credit Agricole said it "is convinced it did not commit an infraction against competition law" and said it would appeal. HSBC said it believes it "did not participate in an anti-competitive cartel" and is considering its legal options.

Vestager said the financial products, which companies use to manage interest rate uncertainty, were traded globally on money markets worth trillions of dollars. The market's manipulation reaped huge profits for the banks, she said.

"If this market is rigged it will benefit only a few and this is exactly what the seven banks did."

She said they exchanged confidential information about trade and strategy in chatrooms and the like to send rates high or low to meet their needs. "The Euribor rate on a specific date can make a huge difference to the cash flow in a bank."

She said the chatrooms were replete with "vulgar language" as the banking officials developed their own vocabulary to drive the collusion between the seven banks and stem fair competition. "It is a very closed community with a very free language, so to speak," she said.

With Wednesday's decisions, the Commission has imposed fines of some 2 billion euros in six cases over the past three years in the sector, she said.