LONDON - Regulators in Britain said on Monday that they had begun criminal proceedings against three former Barclays employees suspected in the manipulation of a global benchmark interest rate.
The Serious Fraud Office said that Peter C. Johnson and Jonathan J. Mathew, both former rate submitters at Barclays, and Stylianos Contogoulas, a former trader, will face charges that they conspired to manipulate the London interbank offered rate, or Libor. The three are to appear in Westminster Magistrates’ Court at a later date, possibly this month.
The fraud took place from June 2005 to August 2007, said the agency, which prosecutes financial crimes in Britain. It did not further detail its case.
Lawyers for Mr. Johnson and Mr. Mathew declined to comment on Monday. The law firm representing Mr. Contogoulas had no immediate comment when reached by telephone on Monday. Barclays also declined to comment.
The new criminal proceedings are the latest development in a broadening investigation into the manipulation of important interest rates.
Some of the world’s largest banks, including UBS, Barclays and Royal Bank of Scotland, have been caught up in the scandal and have agreed to pay billions of dollars to settle allegations with regulators in Britain, the United States and elsewhere.
Three people were already facing criminal charges in Britain. In December, Tom Hayes, a former derivatives trader at UBS and Citigroup, and two former traders at the brokerage firm RP Martin, Terry J. Farr and James A. Gilmour, pleaded not guilty in London.
The trial of Mr. Hayes, who was the first person to be charged criminally in Britain in the scandal last year, is expected to begin in Britain next year. He also faces criminal charges in the United States.
British prosecutors have previously said they have identified 22 individuals as potential co-conspirators in the matter.
On Monday, the antifraud office said its investigation was continuing and that the agency was collaborating with Britain’s Financial Conduct Authority and the United States Department of Justice, which had their own investigations.
To set Libor and other rates, banks submit the rates at which they would be prepared to lend money to one another, on an unsecured basis, in various currencies and varying maturities. Investigations in the past two years have found evidence that traders at the various banks benefited from falsely reported rates.
In December, antitrust regulators in the European Union agreed to settle with eight financial institutions over alleged collusion to manipulate Libor related to the Japanese yen and the euro interbank offered rate, or Euribor. Six of the institutions, including Deutsche Bank, agreed to pay a combined 1.7 billion euros, or about $2.33 billion.
JPMorgan Chase and Citigroup were the first American banks to be fined in the scandal as part of the European Union settlement.
Five financial institutions, including Barclays, UBS and R.B.S., have paid a combined $3 billion to settle with American and British regulators.
