UBS, the world's largest wealth manager and Switzerland's largest bank, has delivered a series of strong results over recent years, booking its best annual profit since the global financial crisis in 2021 and its best first-quarter net profit in 15 years at the start of 2022.

The bank in February unveiled a new strategy focussed on using technology to help it increase revenue and reach more customers, while also continuing to bring costs down.

In the memo to employees, Chief Executive Ralph Hamers credited Zeinler with helping to develop that plan and UBS' future over the course of his tenure at the bank.

"Christian successfully led the development of our strategy on a page, including a set of clear actions behind each of the strategic imperatives we introduced last year," Chief Executive Ralph Hamers said in the memo. "This strategy was just reaffirmed by our Group Executive Board and Board of Directors and will continue to guide our strategic journey."

Zeinler will be replaced on an interim basis by Chief of Staff Marsha Yuan effective July 1, Hamers said.

A spokesperson for UBS confirmed that Zeinler planned to leave the bank to focus on owning and growing small- and medium-sized, primarily family-owned businesses outside the financial services industry.

Zeinler previously headed strategy for UBS' flagship wealth management division before assuming the group strategy role under Hamers in 2021.

Within wealth management, he was credited with devising a strategy which helped to increase pre-tax profits by nearly $2 billion, or half the $4.0 billion the division generated in 2020, Zeinler's last full-year in that role.

(Reporting by Brenna Hughes Neghaiwi; Editing by Emelia Sithole-Matarise)