UBS AG asked a U.S. court on Thursday not to proceed with a high-profile tax evasion case brought against it by the U.S. Internal Revenue Service, saying the case would violate Switzerland's strict bank secrecy laws.

The petition should be denied, Switzerland's largest bank said in a filing to a federal court in Florida.

U.S. tax authorities are pursuing a civil lawsuit against UBS seeking to access the data of 52,000 Americans it says are hiding about $14.8 billion in assets in Swiss bank accounts.

Despite the clear historical record, the IRS now asks this Court to force a Swiss financial institution and its employees, over the express objection of the Swiss Government, to violate Swiss law by producing a massive quantity of confidential account information located exclusively in Switzerland, UBS said in its filing.

The IRS asks this Court to enforce against UBS a broad civil summons seeking information on many thousands of client accounts located exclusively in Switzerland, even though compliance would compel UBS employees to commit crimes in Switzerland, the bank added in its written argument.

(Reporting by Tom Brown and Jim Loney; Editing by Pascal Fletcher, Phil Berlowitz)