By David Enrich and Jenny Strasburg (The Wall Street Journal)
LONDON—British fraud prosecutors next week are expected to publicly name roughly two dozen traders and brokers who they believe were involved in a scheme to manipulate benchmark interest rates, according to people familiar with the plans.

Lawyers representing the U.K.’s Serious Fraud Office are due to appear in a London courtroom Monday for a hearing about their criminal-fraud cases against a former bank trader and two former brokers. At that hearing, the lawyers plan to publicly identify other traders and brokers who allegedly conspired with the defendants to rig the London interbank offered rate, or Libor, these people say.
The planned naming of the alleged co-conspirators—who have not been charged—will dramatically expand the roster of individuals, currently confined to a small handful, who have been publicly linked to the Libor scandal. Among those expected to be named Monday are multiple individuals who currently or until recently worked as traders or brokers in the financial industry.
At Monday’s hearing, former UBS AG UBS +1.15% and Citigroup Inc. C -0.12% trader Tom Hayes is expected to plead not guilty to eight counts of criminal fraud related to his alleged efforts to manipulate benchmark interest rates, according to people familiar with his plans. Two former brokers at R.P. Martin Holdings Ltd., Terry Farr and James Gilmour, charged with similar offenses, are also due to enter pleas. Their lawyers didn’t respond to requests for comment.
Lawyers representing the SFO are planning to present a list of the three defendants’ alleged co-conspirators. Inclusion on the list doesn’t represent a formal accusation of wrongdoing and doesn’t mean the individuals will be charged with crimes. Prosecutors are still finalizing their plans for Monday’s hearing, and it is possible the list of identified individuals will change, say people familiar with the process. Lawyers for some individuals have lobbied the SFO not to publicly name their clients, but those requests don’t appear to have been successful, one lawyer said.
The individuals or their lawyers, and representatives of their past or present employers, either declined to comment on the record, didn’t respond to requests for comment, or couldn’t be reached for comment.
A number of Mr. Hayes’s former colleagues from UBS and Citigroup are expected to be identified as alleged co-conspirators. Michael Pieri, Mr. Hayes’s former boss at UBS in Tokyo, is one of the highest-ranking executives. Mr. Pieri was fired by UBS and currently lives in Australia, according to people familiar with the matter.
Mr. Hayes’s former assistant trader at UBS, Mirhat Alykulov, is also expected to be on the list of co-conspirators. Mr. Alykulov, a Kazakhstan native who currently works for a Tokyo brokerage firm, has been cooperating with U.S. investigators, according to people familiar with the case. In 2011, he phoned Mr. Hayes from the Washington headquarters of the Federal Bureau of Investigation, part of an effort to help U.S. prosecutors build a case against Mr. Hayes, these people said.
British prosecutors believe that Messrs. Pieri and Alykulov helped Mr. Hayes with his alleged attempts to rig Libor by asking their UBS colleagues and others to tinker with Libor data to benefit their trading positions, according to people familiar with the matter.
Christopher Cecere, who was Mr. Hayes’s boss at Citigroup in Tokyo, is also likely to be named, these people say. Mr. Cecere, who resigned from Citigroup in 2010 at the same time that Mr. Hayes was fired, left the Geneva office of hedge fund Brevan Howard in June, according to people familiar with his departure. The reasons for his departure from Brevan aren’t clear.
A handful of traders at major banks are likely to be named for allegedly working with Messrs. Hayes and Farr to manipulate rates. They include Luke Madden, a former HSBC Holdings HSBA.LN -1.14% PLC trader in London; Paul Glands, who used to work for J.P. Morgan Chase & Co. and currently is at Toronto-Dominion Bank’s London investment-banking unit; and Paul Robson, a former London-based trader at Dutch lender Rabobank, these people say.
A number of past and present brokers are also likely to be named at Monday’s court hearing.
Prosecutors are likely to identify a number of former ICAP IAP.LN +0.49% PLC brokers, according to the people familiar with the plans. ICAP last month settled U.S. and British Libor-rigging allegations, agreeing to pay about $87 million and admitting wrongdoing. At the time, the U.S. Justice Department filed criminal charges against three former ICAP brokers for allegedly helping to manipulate rates. Their lawyers haven’t commented.
Two brokers who have worked at London-based interdealer broker Tullett Prebon PLC also are likely to be named in court because prosecutors believe they helped Mr. Hayes manipulate rates, say the people familiar with the matter. Mark Jones left Tullett in 2011 and now works at BGC Partners, according to people familiar with his situation. Noel Cryan left Tullett in the past few weeks, according to an employee on Tullett’s brokerage floor.