LONDON/FRANKFURT Dec 16 ,(Reuters) - Former UBS trader Kweku Adoboli has switched legal teams ahead of his court appearance next week on rogue trading charges.

London law firm Bark & Co, which specializes in fraud cases, said Friday it was now representing Adoboli, who is accused of unauthorized trading which the Swiss bank says cost it some $2.3 billion.

Kingsley Napley, which had until now been representing Adoboli, confirmed it was no longer working on the case. A spokeswoman would not say why Adoboli had parted company with the law firm.

Adoboli faces two charges of fraud and two of false accounting in a case that has shaken the investment banking world, after the losses surfaced in September.

He has yet to enter a plea, but is expected to do so on Dec. 20, when he is due in court.

He was remanded in custody again following his last court appearance in November.

UBS declined to comment.

The British-educated son of a retired United Nations official from Ghana, Adoboli worked as a director of exchange traded funds (ETFs) at UBS.

At an earlier hearing, his lawyer had said Adoboli was "sorry beyond words for what had happened."

Bark & Co, a specialist in complex fraud and tax compliance, has been acting for Asil Nadir, a British businessman facing multi-million pound fraud charges after the collapse of his Polly Peck fruit-to-electronics group.

Adoboli's former legal advisers Kingsley Napley has also advised Nick Leeson, whose $1.4 billion derivatives losses triggered the 1995 collapse of Britain's Barings Bank.

The rogue trading losses uncovered at UBS this year were a big blow to the Swiss bank, which had been trying to bolster its investment banking franchise.

Chief Executive Oswald Gruebel resigned in the wake of the scandal, and has since been replaced by Sergio Ermotti.

Several high level equities bankers have also resigned and a number of employees may still face disciplinary action.

The news of Adoboli's new legal team came as a separate case against a UBS employee was settled.

Jaspreet Singh Ahuja, a former client adviser for UBS, was banned and fined 150,000 pounds ($232,200) by Britain's Financial Services Authority (FSA) for "failing to act with integrity" in allowing a client to break Indian law.

(Reporting by Sarah White and Edward Taylor; additional reporting by Michael Holden, Philip Baillie and Emma Thomasson)

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