Former deputy prime minister Wong Kan Seng has joined United Overseas Bank as an independent, non-executive director.
Mr Wong, 70, was appointed alongside others as part of moves to increase the size of its board.
In an exchange filing on Thursday night, the bank said: "Increasing the board size would be beneficial to the bank, especially with a view to ensure that there is a pipeline of critical skills following the retirement of directors."
Its nominating committee had "mapped the skill sets and expertise" on the board against what it said was an ideal framework, to identify further skills required.
The appointments include Sats president and chief executive Alexander Hungate, 50, WongPartnership chairman Alvin Yeo Khirn Hai, 55, and Mr Michael Lien Jown Leam, 53, executive chairman of Wah Hin & Co - a private investment holding company - and grandson of the late banker and philanthropist Lien Ying Chow. Mr Lien had previously been a non-executive director from 2005 to 2009.