NEW YORK (AP) -- Financial regulators in Singapore have asked Citigroup (NYSE:C) to turn over documents related to information that the lender has submitted to the British banking authority that sets some global interest rates.

The request from the Monetary Authority of Singapore is one of several that Citigroup has received from regulators in the U.S. and overseas, the bank said in a regulatory filing Tuesday.

The move comes amid growing scrutiny over the possible manipulation of an interest rate known as LIBOR, which is short for London Interbank Offered Rate.

The rate is used to set the interest rates on trillions of dollars in contracts around the world, including mortgages and credit cards. It is a self-policing system and relies on information that global banks provide to the British banking authority.

In August the attorneys general of New York and Connecticut issued subpoenas to Citigroup and six other banks over possible manipulation of the LIBOR.

U.S. and British regulators have already fined Barclays (NYSE:BCS), based in the U.K., $453 million for submitting false information between 2005 and 2009 to keep the interest rate low.

In its filing Citigroup said it is cooperating with the inquiries and investigations.

Shares of Citigroup, based in New York, rose $1.08, or 2.9 percent, to $38.40 in afternoon trading.

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