The bank named interim head Sergio Ermotti as new its chief executive and announced former Bundesbank president Axel Weber will succeed Kaspar Villiger as board chairman from May 2012, a year earlier than planned.
Ermotti, 51, has been acting head of UBS since the departure of Oswald Grübel in September in the wake of a rogue trading scandal.
It was another blow to the bank, which has been struggling to rebuild its reputation after the financial and economic crises when it lost colossal sums and was forced to turn to the state for a rescue package.
In 2008 and 2009, the bank was also embroiled in a serious tax evasion spat with the United States.
Villiger welcomed the new appointments which he said would bring "essential stability and clarity" to UBS.
"It will enable the bank to master the many current economic challenges and regulatory changes facing it, and will ensure its success over the long term for clients, shareholders and employees," the chairman said in a statement.
At a press conference Villiger, who has headed the board since 2009, said the bank had rid itself of the toxic assets which led to its near collapse, had resolved the US tax dispute and was now making "a generation change."
Ermotti, formerly of Merrill Lynch and Unicredit, said the institution had made "an important step" in ensuring the bank's success.
UBS will unveil its new strategy at its investors day in New York on Thursday which Ermotti said would involve a "focused, less complex and less capital-intensive investment bank," without giving further detail.
Thursday may also see a job cuts announcement. UBS already revealed in August it was to axe 3,500 posts, of which 45 percent were in investment banking, due to market volatility and the strong Swiss franc.
"The era of the Grübel/Villiger 'clean-up team' will come to an end at the next annual general meeting," analysts at Wegelin said.
At the end of October UBS posted a third-quarter net profit of 1.018 billion francs ($1.16 billion) despite taking a massive hit after London trader Kweku Adoboli was arrested over a trading scandal.