The Swiss bank will fight a costly conviction in France, further prolonging an eight-year legal quagmire.

Zurich-based UBS lodged an appeal to French criminal court ruling which upheld its guilty conviction over tax offenses and money laundering, it said in a statement on Monday.

«This enables UBS AG to thoroughly assess the verdict of the Court of Appeal and to determine next steps in the best interest of its stakeholders,» the bank said in a press release. Last week's ruling lowered UBS' fine to 3.75 billion euros ($4.2 billion), plus damages of 800 million euros.

Protecting Other Areas

It had already ponied up a 1 billion «caution,» or corporate bail. France represents the largest chunk of litigation or regulatory problems that UBS still has outstanding. 

UBS' appetite for a fight is likely a bid to protect other parts of its business: a conviction on the French charges may lead clients in U.S. public pensions or major institutional clients in Asia to reconsider their business with UBS.