Singapore - Ho Ching, the chief executive officer of Singapore's state investment company Temasek Holdings (Pte) Ltd, will step down and be replaced by Charles W Goodyear, the former boss of the global resources company BHP Billiton, Temasek announced Friday.

Goodyear, a 51 year old US-citizen, was to succeed Ho on October 1, 2009, the company said. He already joined the Temasek board and will assume the position of CEO-designate on March 1.

Ho, the wife of Singapore's Prime Minister Lee Hsien Loong, has been CEO of Temasek since January 2004.

The company did not give any reason for her departure. The Board, including Ho, had been addressing succession planning annually since early 2005, Temasek Holdings said in a statement.

Temasek Holdings holds and manages a diversified portfolio worth 185 billion Singapore dollars (123 billion US dollars). (dpa)