The Serious Fraud Office has begun criminal proceedings against Noel Cryan, a former employee at Tullett Prebon Group, in connection with the manipulation of LIBOR.

The Serious Fraud Office has begun criminal proceedings against Noel Cryan, a former employee at Tullett Prebon Group, in connection with the manipulation of LIBOR.

It is alleged he conspired to defraud between 1 February 2009 and 3 December 2009, the SFO said in a statement.

He becomes the thirteenth person in the UK to face charges from the SFO in its investigation over the manipulation of LIBOR.

In a statement, Tullett Prebon noted the announcement by the SFO that it has issued criminal proceedings against Cryan.

“Tullett Prebon continues to cooperate fully with the FCA and other regulators and government agencies in connection with their enquiries,” the statement said.

On 3 October, a senior banker from a leading UK bank became the first person in the UK to be convicted of rigging the LIBOR rate.

The man and the bank cannot be named for legal reasons.

The SFO's investigation began in July 2012 after it emerged that a number of banks were manipulating the LIBOR rate for their own benefit.

So far, seven banks and brokerages have been fined by UK and US authorities in the LIBOR-rigging investigation, paying more than $3 billion.

The SFO has charged 11 other individuals who are currently awaiting trial and the investigation into others continues.

In July, partly state-owned Lloyds Banking Group was fined $370 million by UK and US authorities for the manipulation of LIBOR and other benchmark failings, while Rabobank agreed to pay more than $1 billion in criminal and civil penalties for its role in manipulating the benchmark in October last year.

Meanwhile, two years ago, Barclays was fined $450 million by US and UK regulators for trying to manipulate LIBOR, which led to the resignations of Barclays' chief executive Bob Diamond and chairman Marcus Agius in the UK.

Last month, Lloyds Banking Group dismissed eight staff following a major investigation into LIBOR rigging, saving around £3 million ($4.82 million) in unpaid bonuses as a result.

At the end of last year, the European Union also levied a record fine of €1.7 billion ($2.16 billion) on six European and US banks, including Deutsche Bank, Societe Generale, Royal Bank of Scotland, and Citigroup.

LIBOR is based on the interest rates leading banks charge when loaning money to other banks overnight, which is supposed to represent the cost of a bank's lending activities.