A former City trader has been jailed for 14 years after becoming the first person to be convicted by a jury of rigging Libor rates in a scandal that rocked financial markets.Tom Hayes, 35, a former senior trader at UBS and Citigroup, was convicted on all eight counts of conspiracy to defraud in a landmark case for the Serious Fraud Office following a multi-million pound investigation into manipulation of benchmark interest rates.

He originally indicated he could plead guilty only to change his plea after he was sure he no longer faced the threat of extradition to the United States. If extradited to the US he could have been handed a much longer sentence.

Mr Justice Cook, the judge leading the trial, said in a pre-trial hearing in October that Hayes was “a gambler by nature” adding the evidence against him made it an “open and shut case”.

Speaking at the sentencing hearing this afternoon he said: “What this case has shown is the absence of that integrity which ought to characterise banking.

“You, as a regulated banker, succumbed to temptation in an unregulated activity because you could.”

The guilty verdicts follow a nine-week trial during which Hayes denied he had successfully moved Yen borrowing rates, despite reams of electronic messages, telephone call records, and even 82 hours of interviews with the SFO in which he admitted he had actively sought to rig Libor for several years.

The highly-paid ex-trader orchestrated a scheme to interfere with the rate in order to boost his own six-figure earnings, London’s Southwark Crown Court heard.

In an audio clip he said “influencing” Libor was “commonplace” and admitted he was a “serial offender”.

A husband and father-of-one who had superhero bedding and shunned pints in City pubs in favour of hot chocolate seemed like an unlikely villain at times during the trial. A maths graduate with mild autism, he claimed he was no “ringmaster” in a scandal and more “Rain Man” to colleagues – a reference to the film of the same name starring Dustin Hoffman as an awkward maths genius who suffers from the disorder.

But behind his unassuming outward demeanor lay a “greedy” man motivated by money who was at the heart of a massive financial fraud, the court heard. Prosecutors said he would “cajole”, “bribe” and “beg” brokers to manipulate the London interbank offered rate, better known as Libor.

The former Yen derivatives trader denied eight counts of conspiracy to defraud covering a period from 2006 to 2010, when he worked for Switzerland’s UBS and America’s Citigroup.

But a jury of seven men and five women found Hayes, of Fleet, Hampshire, guilty of all eight counts.

UBS moved quickly to distance itself from its former employee saying it was committed to, “upholding a culture of doing the right thing.” In a statement released shortly after the verdicts it added: “UBS was not a party to this case […] It was a matter between the SFO (Britain’s Serious Fraud Office) and Mr Hayes and UBS has no comment.”

Citigroup said it had no comment.

Hayes stared straight ahead emotionless as the verdicts were read out. His wife and parents sat with their heads bowed as they heard the verdicts.

The case marks the first successful conviction in the UK following a multi-million pound investigation over several years into market manipulation that had already seen banks, including Barclays, Lloyds and Royal Bank of Scotland, pay out billions in fines to regulators in this country and the US.