Swiss bank UBS has raised its estimated losses due to unauthorised trading to $US2.3 billion from an initial $US2 billion.
London trader Kweku Adoboli, 31, was charged with fraud and false accounting at a court in London on Friday. He was arrested early on Thursday and has been remanded in custody until 22 September.
According to the charges, the fraud took place between January - September this year.
In a brief statement issued on Sunday, UBS said:
''The loss resulted from unauthorised speculative trading in various S&P 500, DAX, and EuroStoxx index futures over the last three months.
"The loss arising from this matter is $US2.3 billion. As previously stated, no client positions were affected.''
UBS lost £35 billion in the 2007-08 banking crisis and had to be bailed out by the Swiss government in 2008.
In February 2009, the bank announced that it had lost nearly $US17 billion in 2008.
The BBC reports UBS operates in all of the major financial centres worldwide, with offices in over 50 countries. It has 65,000 employees worldwide. The bank was founded 150 years ago.