The authorities have been investigating the bank’s role in encouraging its wealthy French customers to open accounts outside the country to evade taxes. The parent company in Switzerland is also being investigated.
The €1.1bn in bail was imposed on UBS in July and was ordered to pay by 30 September. The bank appealed against it in a court saying that the amount was ‘unprecedented and unwarranted’.
UBS plans to appeal the decision in the supreme court in addition to taking it up at the European Court of Human Rights.
"UBS is very disappointed at the decision which fails to take into account the arguments put forward at the hearing.
"We continue to believe that this is a highly politicized process that from the beginning of the investigation has not followed elementary facets of the rule of law," the bank said in a statement.
In July, UBS agreed to pay €300m to settle similar charges in Germany. It was fined €10m last year by French banking regulator and paid $780m to the US authorities in 2009 on money laundering charges.
The court ruling comes at a time when French President Francois Hollande has begun cracking down on tax evaders after one his ministers was found to be holding an undeclared overseas bank account for two decades.
