Prime Minister Lee Hsien Loong paid a glowing tribute to outgoing Temasek Holdings chairman S Dhanabalan who is stepping down after 17 years of chairing the Singapore investment firm.

In a personal letter addressed to Mr Dhanabalan, a former Cabinet minister, Mr Lee thanked him for playing a key role in reshaping Temasek's investment strategy, from one focusing mainly on Singapore to one that harnesses the twin engines of growth in Singapore and Asia.

Mr Dhanabalan was also praised for steering the company through the 1997-1998 Asian Financial Crisis as well as the recent global financial crisis.

Mr Lee highlighted Mr Dhanabalan's achievements in instilling a forward-looking culture in the firm and for personally mentoring many officers who have gone on to hold senior leadership positions.

"You have been an exemplary chairman. You provided strong leadership and steady support to the board and management. Temasek has grown into a Singapore icon, distinguishing itself as an active investor, a forward-looking institution and a trusted steward," said Mr Lee.

He added: "On a personal note, I would like to thank you for your signal contributions to Singapore. For half a century, you have served with distinction in the public service, political office and now Temasek. Throughout your career, you upheld the highest standards of integrity and probity, and demonstrated commitment, thoughtfulness and resilience. You are an exemplar to your successors and an inspiration to all Singaporeans."