UPDATE 1-Caisse de depot CEO Richard Guay to step down

TORONTO, Jan 5 (Reuters) - Richard Guay, the head of Canada’s biggest pension-fund manager, Caisse de depot et placement du Quebec [CDPDA.UL], is stepping down and becoming a strategic adviser, after being away on medical leave.

Guay will resign effective Jan. 7. He was appointed president and chief executive on Sept. 5, 2008, and has been with the Caisse since 1995.

He was said to be suffering from exhaustion and went on leave on his doctor’s advice in mid-November. The medical leave was extended in December and was to finish on Monday.

Fernand Perreault will become president and CEO of the institutional money manager for a period of six months, ending July 7. Perreault was leading the Caisse’s executive committee and co-ordinating operations until Guay was due to return.

The board will recruit a new president and CEO at the appropriate time, the Caisse said in a statement. (Reporting by Ka Yan Ng; editing by Rob Wilson)