Villiger was quoted by the daily Swiss newspaper NZZ in its Saturday edition, reports carrying a translation of his remarks as saying.

"We would like to remain an integrated bank, which sucessfully acts globally out of Switzerland," Villiger is quoted as saying, adding that the company's investment bank is "a necessary service."

He said UBS aims to reach a pre-tax profit of about SFr15 billion (around $15.93 billion) in three to five years.

Villiger said pressure on the country's banking secrecy has prompted German clients with lower assets to move their funds out of UBS, but he added that "surprisingly many pay their taxes and stay with UBS," the report said.

In a separate report by Bloomberg, Government of Singapore Investment Corp, the biggest investor in UBS – and Citigroup - plans to hold on to its stakes in the banks for “many years” and will only consider selling if there are attractive offers.

“We look to continue to hold on to our stakes in UBS and Citigroup for many years to come,” Tony Tan, deputy chairman of the Singapore sovereign wealth fund, said in an interview at Davos, Switzerland, where he attended the annual World Economic Forum conference. "But one never says never; if someone offers an extremely high price, of course we’ll look at the possibility.”

GIC bought stakes in New York-based Citigroup and UBS, Switzerland’s biggest bank, three years ago.