UBS replaces CEO

Rohner had been in the role just over a year and a half, since being promoted in July 2007 from chief risk officer to head of the banking group. According to UBS, he told the bank's board in early January that he intended to retire, but neither Rohner nor the board saw fit to inform shareholders or the rest of the bank's staff until today.

Grübel was previously group chief executive at Credit Suisse until he stepped down in May 2007. He had worked at Credit Suisse since 1985, holding posts including head of global trading for the investment banking division and chief executive of the private bank.

Grübel said: "I am convinced that the Swiss financial centre requires the presence of more than one big global bank. The opportunity to lead UBS with its unique client franchise in wealth management, investment banking and asset management in these extraordinary times presents a fascinating, yet formidable challenge to me. Together with our 77,000 dedicated employees, I will do all I can to bring UBS back on a profitable, successful track."

The high-profile management change follows the bank's announcement earlier this month that it made a fourth quarter net loss of Sfr8.1 billion ($7 billion), bringing its full-year 2008 net losses to Sfr19.7 billion.

See also: UBS credit derivatives head departs
Q4 loss of Sfr8.1 billion for UBS