Ex-UBS trader charged in U.K. LIBOR manipulation probe

Tom Hayes, the former UBS and Citigroup derivatives trader, was charged as part of the U.K.'s investigation into manipulation of the London interbank offered rate.

Mr. Hayes was charged with eight counts of conspiracy to defraud Tuesday, according to a statement from the U.K. Serious Fraud Office. He will appear at a London court on Thursday, said David Jones, an SFO spokesman.

Mr. Hayes, a British national who worked in Tokyo, was arrested in the U.K. probe on Dec. 11 and charged by the U.S. Justice Department the following day, along with one of his former co-workers from UBS. The U.S. charge was made public on Dec. 19, the same day UBS was fined $1.5 billion by U.S., British and Swiss regulators for trying to rig LIBOR and similar benchmarks.

Two employees of the brokerage RP Martin Holdings Ltd. were arrested by City of London police in the same probe. Mr. Hayes has been charged in the U.S. with wire fraud and antitrust violations.

Mr. Hayes joined UBS in 2006 and worked at the Swiss lender until 2009, when he joined Citigroup. He was dismissed by Citigroup less than a year later for involvement in suspected rate-rigging, a person with knowledge of the matter said in October. He worked at Edinburgh-based RBS from 2001 to 2003.

Mr. Hayes' London lawyer, Lydia Jonson, didn't immediately respond to a phone message and e-mail requesting comment.

Global regulators have fined UBS, Barclays and Royal Bank of Scotland Group about $2.5 billion in the past year for distorting LIBOR and similar benchmarks. At least a dozen firms remain under investigation around the world.

Last week, Singapore's monetary authority censured 20 banks for attempting to fix interest rate levels and ordered them to set aside as much as $9.6 billion.

More than $300 trillion of loans, financial products and contracts are linked to LIBOR. Regulators are looking at how derivative traders and bankers who submitted interest-rate data colluded to ensure benchmarks benefited their own trades, and whether lenders low-balled submissions in 2008 to hide their true cost of borrowing.