Switzerland's financial markets regulator is investigating several Swiss banks in connection with the possible manipulation of foreign exchange rates, it said on Friday.
Financial benchmarks have come under increased global scrutiny after the discovery that a key benchmark interest rate had been rigged.
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"FINMA is coordinating closely with authorities in other countries as multiple banks around the world are potentially implicated," the Swiss regulator said in a statement.
It said it would give no further details on the investigations or the banks potentially involved.
Britain's financial watchdog, the Financial Conduct Authority (FCA), said in June it was looking into a report that traders manipulated benchmark foreign exchange rates that are widely used by companies and funds.
A spokesman for the FCA declined to say whether it was working with FINMA on its probe.
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UBS and Credit Suisse declined to comment while a spokesman for Zuercher Kantonal Bank said the bank was currently not aware of a FINMA investigation.
Marc Buerki, CEO of Swissquote, said they were not part of the investigation.
To date, U.S. and British authorities have charged seven men and fined four financial firms about $2.7 billion in the investigation into the manipulation of the London interbank offered rate (Libor), used as a benchmark for more than $300 trillion of financial products.
Britain's leading prosecutor, the Serious Fraud Office (SFO), said on Thursday it was poised to charge more individuals in connection with the Libor scandal.
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