Oswald Gruebel, the chief executive of UBS, said he will not take a bonus this year and said the Swiss bank had limited its investment banking proprietary trading operations, according to Reuters, citing a Sunday newspaper report.

Meanwhile, in a separate interview, Urs Rohner, vice chairman of UBS’s main rival, Credit Suisse, said banks with a global reach that combined private and investment banking had withstood the financial crisis best.

UBS's Mr Gruebel told the Swiss newspaper Sonntag that bank employees would have to be paid bonuses to prevent the best ones from leaving.

"Otherwise all the good people will leave UBS. Why should they stay," he was reported as saying.

"Of course I won't take a bonus. No, because the company's not making a profit,” he was quoted as saying.

The comments came after the world’s banking industry was digesting the potential global, as well as US, impact of recent proposals by US president Barack Obama to curb the size of his country’s banks and force them to shed proprietary trading arms and activities such as hedge funds. The proposals were designed, Mr Obama said, to limit the danger that future risk-taking by banks would hurt the entire financial system.

The issue of bonus payments to bank executives remains a thorny one as some of the banks to be awarding bonuses, such as Goldman Sachs, had received substantial aid from the taxpayer, although in Goldman’s case, it has been repaid in full.

UBS will publish fourth-quarter results on 9 February.