Kweku Adoboli worked as a trader for the Swiss Bank UBS in the global synthetic equities division in London [EPA]

The former UBS trader accused of unauthorised deals that cost the Swiss bank $2.3bn pleaded not guilty to four fraud and false accounting charges in a London court.

Kweku Adoboli, 31, the British-educated son of a retired United Nations official from Ghana, was arrested and charged in September in connection with one of the world's biggest cases of alleged "rogue trading".

The losses shook the Swiss bank, leading to the resignation of former chief executive Oswald Gruebel and a shake-up of its investment arm to cut its exposure to risk.

The trial is expected to shed light on the bank's management, traders and risk controls.

Adoboli, who faces a maximum 10-year jail sentence if found guilty, spoke only to confirm his name and reply "not guilty" to all the charges when they were read out to him at a packed Southwark Crown Court.

Judge Alistair McCreath remanded Adoboli in custody and set the start of the trial for September 3.

"An earlier trial would be simply not possible," he said.

At his last hearing on December 20, Adoboli's lawyers said he had changed legal teams because he was unhappy with the advice he had received.

That meant he had been unable to enter a meaningful plea, his new defence lawyer Paul Garlick told the court at the time.

Adoboli worked for UBS's global synthetic equities division in the City of London financial district, buying and selling funds which track different types of stocks or commodities such as precious metals.

He was arrested at the bank's offices on September 15.

UBS chief executive Sergio Ermotti said in November that the bank was committed to "addressing the causes" of the incident.

The bank said last September that unauthorised trading in its investment division lost the bank $2.3bn, rocking an industry already trying to cope with the euro zone debt crisis and a global slowdown.

The Swiss bank came close to collapse during the 2008 financial crisis because of its exposure to bad loans in the mortgage market. It cut thousands of jobs and received a state bailout.

The bank's recovery was then threatened by uncertainty over a deal between Switzerland and the US government designed to clamp down on tax evasion.