A rogue trader who carried out the UK's largest ever fraud, losing £1.4 billion in bad deals which nearly brought down a major international bank, was jailed for seven years today.

At one point during his run of losses, former rising star City trader Kweku Adoboli, 32, stood to run up losses of 12 billion US dollars (£7.5 billion) for employer UBS.

City of London Police, which investigated his activities after he confessed his losses in an email to colleagues, said he was one of the most sophisticated fraudsters the force had come across.

Adoboli was accused of exceeding his multi million-pound trading limits and failing to hedge trades, faking records to cover his tracks at the Swiss bank's London office.

He admitted the losses but claimed that he was pressured by staff to take risks, culminating in bad deals which wiped £2.8 billion off the bank's share value when they were discovered.

The Ghanaian-born former public schoolboy was sentenced after a trial that lasted more than nine weeks at Southwark Crown Court in London.

The jury convicted him unanimously of one count of fraud linked to the £1.4 billion loss.

He was found guilty of a second fraud charge by majority verdict but cleared of four remaining charges of false accounting after the jury deliberated for 16-and-a-half hours across five days.

Jailing him, trial judge Mr Justice Keith told Adoboli: "There is a strong streak of the gambler in you. You were arrogant to think the bank's rules for traders did not apply to you."

Adoboli wiped away tears as he sat in the dock during the sentencing.

Mr Justice Keith told him: "Whatever the verdict of the jury you would forever have been known as the man responsible for the largest trading loss in British banking history."

He added: "Your fall from grace as a result of these convictions is spectacular.

"The fact is you are profoundly unselfconscious of your own failings."

He sentenced Adoboli to seven years for a charge of fraud by abuse of position relating to the £1.4 billion loss and four years for the other, to be served concurrently.

He will serve half in prison before being released on licence, the judge added.

UBS said in a statement: "We are glad that the criminal proceedings have reached a conclusion and thank the police and the UK authorities for their professional handling of this case. We have no further comment."

Andrew Penhale, deputy head of fraud at the Crown Prosecution Service (CPS), told reporters outside the court: "Behind all the technical financial jargon in this case, the question for the jury was whether Kweku Adoboli had acted dishonestly, in causing a loss to the bank of 2.3 billion US dollars.

"He did so, by breaking the rules, covering up and lying. In any business context, his actions amounted to fraud, pure and simple.

"The amount of money involved was staggering, impacting hugely on the bank but also on their employees, shareholders and investors. This was not a victimless crime.

"The CPS Central Fraud Division are pleased to have brought this case so quickly to conclusion, with the trial opening one year to the day after the case was reported to City of London Police.

"This is a tribute to the hard work and dedication of the whole prosecution team.

"People who commit fraud, in any walk of life, should know that the scale and technicality of a case is no barrier to bringing it to justice. At the heart of any complex fraud is a simple notion of dishonesty which is something that we can all understand."