No documents were seized at UBS's offices in Wednesday's search, which was part of a probe into suspected tax evasion by UBS clients.

"The investigation of the German authorities is not related to a criminal or civil proceeding against UBS," the bank said.

The statement expands on Wednesday's comment, when UBS said there were no investigative proceedings against any employees of its Frankfurt unit.

In 2014, UBS paid about 300 million euros (264.17 million pounds) to settle claims by the authorities in Germany's western city of Bochum that it helped wealthy Germans dodge taxes.

(Reporting by Joshua Franklin; Editing by Edmund Blair)