Ex-citigroup, RP Martin workers held in Libor probe

A former Citigroup Inc. trader is among three people held in the first U.K. arrests as part of global probes into tampering with the London interbank offered rate, according to two people familiar with the matter.

Thomas Hayes, a former trader at UBSAG and Citigroup, was arrested by the Serious Fraud Office (SFO) and City of London Police today, said the people, who asked not to be identified citing the continuing investigation. The other two men arrested worked at brokerage firm RP Martin Holdings Ltd., according to one of the people and a third person familiar with the investigation, who also requested anonymity.

The three men, ranging in age from 33 to 47, are all British nationals living in the U.K. and were taken to a London police station for questioning, the SFO said in a statement.

Global authorities are investigating claims that more than a dozen banks altered submissions used to set benchmarks such as Libor to profit from bets on interest-rate derivatives or make the lenders’ finances appear healthier. Swiss lender UBS is expected to face a fine as early as this week that may surpass the record $466.6 million paid in June by Barclays Plc, the U.K.’s second-biggest bank, to settle claims it attempted to manipulate Libor.

The agency and police also searched three homes in Surrey and Essex. Arrests in the U.K. are made early in investigations, allowing people, who may not be charged, to be questioned under caution.

Hayes, a Tokyo-based trader for Citigroup, was previously dismissed for suspected involvement in the rate manipulation, two people familiar with the situation said earlier this year.

Jeff French, a spokesman for Citigroup in London, declined to comment or provide contact information for Hayes. A number for Hayes couldn’t immediately be located.

An RP Martin spokesman said the company doesn’t comment on employee matters. David Jones, an SFO spokesman, declined to comment beyond the statement. The City of London Police referred all calls to the SFO.

David Green, the director of the SFO, said in an interview last month the agency is considering levying conspiracy-to-defraud charges against individuals. Green said the agency is focusing on the most egregious attempts to manipulate Libor and other related rates. Investigations into firms, managers, traders and rate setters at lesser offenders will come later.

Libor, a benchmark for more than $300 trillion of financial products worldwide, is derived from a survey of banks conducted each day on behalf of the British Bankers’ Association in London. The rates help determine borrowing costs for everything from mortgages to student loans.