UBS trader Kweku Adoboli faced a new fraud charge when he made a brief court appearance in London on Thursday for a hearing over alleged unauthorized trading which the Swiss bank has said cost it $2.3 billion.

Adoboli, already accused of fraud amounting to more than $1.5 billion, has now also been charged with fraud dating between October 2008 and December 2010, which prosecutors said related to reckless and inappropriate trades.

Wearing a grey suit, the 31-year-old bowed to the public gallery when he entered a packed courtroom at the City of London magistrates court.

Adoboli acknowledged several acquaintances in the public gallery and spoke in a confident voice to confirm his name and address, but made no other statement.

Lawyer Patrick Gibbs said Adoboli was sorry beyond words for what had happened. He did not enter a plea and was remanded in custody until a further hearing next month.

He stands now appalled at the scale of the consequences of his disastrous miscalculations, Gibbs said.

Adoboli, the British-educated son of a retired United Nations official from Ghana, was arrested last week.

The case has prompted criticism of the bank's control mechanism and its business model embracing wealth management and investment banking.

(Reporting by Michael Holden; Editing by David Hulmes)