Instead, Koh will take Michael Fam's place as the chairman of Singapore Airlines.
The telco released a statement yesterday announcing that it has put up SingTel director and NatSteel Ltd president Ang Kong Hua to assume the chairmanship, subject to his re-election to the board.
Koh first became chairman of Singapore's largest telco in October 1986. It was then a statutary board. He continued in that capacity as the company was corporatized, and past its listing in 1993.
Under his chairmanship, the company has gone regional. Over the past decade, the SingTel Group has made investments in more than 20 countries, which are now worth S$5.5 billion.
Koh still serves as chairman of Internet Technology Group Ltd and Omni Industries Ltd, and sits on the boards of other companies. He is chairman of the Nanyang Technological University Council, a member of the Securities Industry Council and a director of the Singapore International Foundation, as well as the Institute of Policy Studies.
Koh's nominated replacement, Ang, has been with NatSteel since 1975. He was appointed a non-executive director of SingTel in May. Prior to NatSteel, Ang had been with the Economic Development Board and the Development Bank of Singapore. He is also chairman of the Securities Industry Council and a member of the Singapore Labour Foundation Board.