Former UBS chairman Marcel Ospel and two other directors have waived bonuses worth a total of SFr33 million ($27.8 million).
Two-thirds was due to Ospel, with the remainder going to former vice-president Stephan Haeringer and former finance chief Marco Suter, confirmed a spokesman for the three on Tuesday.
A bank statement said the three men were reacting to their roles in the decisions that have cost UBS more than $40 billion in writedowns and losses over the past year.
The centre-right Radical Party and Christian Democratic Party, as well as the rightwing Swiss People's Party said on Tuesday evening that the paybacks were a long overdue step toward accountability and rebuilding trust.
Earlier this month former chief executive Peter Wuffli said he would not take SFr12 million owed to him after he stepped down in 2007.
That move followed months of mounting pressure from shareholders, the public, banking regulators and government ministers. This intensified in October when the Swiss National Bank bailed out UBS with a SFr6 billion cash injection and agreed to cover toxic assets.
Ospel, who quit Switzerland's largest bank in April, has been the target of a Swiss media campaign demanding that he repay his sizeable paycheck.
Under his chairmanship UBS carried out the aggressive risk-taking strategy in the United States that nearly brought the bank to its knees when the credit crisis hit.
"I hope that my action will help to resolve a situation that was inconceivable to me until a short time ago," Ospel said in a statement.
The announcement came days after UBS, which is struggling to recover from the subprime crisis and has been criticised for its pay structure, announced a more transparent pay system.
Last week it announced it would no longer pay bonuses based on short-term goals after a public outcry against the "culture of greed".
From 2009, bonuses will be held back and forfeited if long-term results are not reached. Board members have waived bonuses this year after UBS racked up $44 billion of subprime mortgage losses.
"The move to forfeit the remuneration is entirely voluntary and should in no way be construed as an admission of guilt in a legal sense," the bank statement said on Tuesday.
A UBS spokesman thanked the former executives and said the bank welcomes their decision, which could spur more people to come forward.
"We will see if others will follow the example," said Rebecca Garcia of UBS.
Shares in the bank rose 8.35 per cent on Tuesday to close at SFr14.93.
swissinfo with agencies
UBS endured a tough 2007 and things seem to have hardly improved in 2008, mainly as a result of the US subprime mortgage crisis.
In July 2007, chief executive Peter Wuffli stepped down following the collapse of the bank's hedge fund Dillon Read Capital Management.
In October 2007, UBS said it would cut 1,500 jobs in its investment banking arm, including that of its head Huw Jenkins. Chief financial officer, Clive Standish, left at the same time.
UBS has written down about $43 billion as a result of the subprime mortgage market collapse. Chairman Marcel Ospel stepped down in April.
The Swiss Federal Banking Commission recently reached the same conclusions as UBS as to how the downturn came about. Based on internal investigations at the bank, the commission found management lapses and "insufficient identification of pertinent risks".
According to the office, UBS didn't know until August 2007 the exact nature of the risks in the subprime realm. Bankers had too much confidence in risk measurement mechanisms, which, retrospectively, is "a serious lack on the part of the bank".
UBS was this year also investigated for allegedly helping US citizens evade taxes, following a confession from a former employee. The case led to UBS stating it would stop offshore banking activities in the US.
Clients have withdrawn tens of billions of Swiss francs in assets from UBS since mid-September.