UBS on Thursday said its highest-ranking executive in Asia is leaving, the latest in a string of high-profile departures from the Swiss bank.

Zurich-based UBS said Rory Tapner, chairman and chief executive of the bank's business in Asia-Pacific, will step down with immediate effect. UBS gave no further details for 50-year-old Tapner's departure, and a spokesman declined further comment. Tapner, a British citizen who had held the top Asia job at UBS for over five years, wasn't immediately available for comment.