UBS said the board had also decided to propose former Bundesbank boss Axel Weber to succeed Kaspar Villiger as chairman at the annual general meeting in May, a year earlier than originally planned.
It also said the board had decided on the bank's future strategy, to be presented at an investor day in New York on Thursday.
This strategy will be centered on our leading wealth management businesses and our position as the strongest universal bank in Switzerland, Ermotti said in a statement.
A focused, less complex and less capital-intensive Investment Bank and our asset management business are also key elements for growing our wealth management franchise.
The appointment represents a rapid ascent for Ermotti, a former UniCredit deputy boss who joined UBS in April. Ermotti's most urgent priority is to restore trust following the trading scandal and to scale back the investment bank amid a glut of new capital rules for riskier activities.
(Reporting by Katharina Bart)