The European Commission said yesterday it had sent legal warnings to banks in Germany and the Netherlands, alleging they broke European Union antitrust rules by operating a cartel setting fees for euro area currencies.

"The Commission's investigation, based on surprise inspections at a number of banks and on replies to questionnaires sent to most eurozone banks, has shown that banks and national associations may have colluded to keep the commissions at a high level or to control their decrease," the Commission said in a statement.

The warnings follow similar "statements of objection" sent to 110 banks and banking federations last month.

Statements of objection are legal warnings setting out the Commission's allegations and giving the companies targeted time to defend themselves. The German and Dutch banks have until the beginning of November to respond.

Some 32 warnings were sent, to banks, their subsidiaries and national federations.