LONDON — Tom Hayes, the former UBS and Citigroup trader, conspired with employees of at least five other banks and three interdealer brokers over a four-year period to manipulate Yen Libor rates, prosecutors said Thursday.
Hayes appeared at a London criminal court for the first time Thursday, and prosecutors laid out the charges against him. The 33-year-old was charged with working with employees at JPMorgan Chase, Royal Bank of Scotland Group, HSBC Holdings, Rabobank Groep, and Deutsche Bank, as well as Tullett Prebon, ICAP, and RP Martin Holdings, Britain’s Serious Fraud Office read out in documents Thursday.
The charges come almost a year after Barclays became the first of three banks fined as part of global regulators’ probes into the London interbank offered rate and other benchmarks. Hayes has also been charged by the Justice Department, which is running a parallel criminal investigation.
Hayes tried to manipulate rates ‘‘with the intention that the economic interests of others would be prejudiced and/or to make personal gain for themselves or another,’’ British prosecutors said in the indictment.
Hayes faces eight counts of conspiracy to defraud, four covering the period from Aug. 8, 2006, to Dec. 3, 2009, while he worked at UBS, and the other four from Dec. 1, 2009, to Sept. 7, 2010, when he was at Citigroup.
In the courtroom, Hayes spoke only to say his name, his address in Surrey, England, and date of birth. His lawyer, Lydia Jonson, declined to comment on a plea.
Judge Quentin Purdy transferred Hayes’s case from Westminster Magistrates Court to a higher criminal court. He is scheduled to appear at Southwark Crown Court on July 4. Charges haven’t been filed in Britain against anyone else in the investigation related to the manipulation of Libor.
Hayes was granted a continuation of his bail conditions, which include a ban from traveling outside Britain and from contacting other suspects in the case. A lawyer for the SFO asked that the names not be read out in open court.
ICAP said in a statement that it has cooperated with the SFO probe.
‘‘We understand several other individuals have been referred to in the charges against Hayes, including unnamed employees of one of ICAP’s Global Broking subsidiaries,’’ ICAP said. ‘‘However, no ICAP company has been charged.’’
Spokespeople from nine other banks involved in the case declined to comment.
Hayes, a Briton who worked in Tokyo, was arrested along with two RP Martin employees Dec. 11 in a British probe. Hayes was charged June 18 with after he answered police bail in central London.
Hayes worked at Swiss lender UBS from 2006 to 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.
The SFO said June 18 that their probe into rate-rigging is continuing.