Rose will be succeeded as chief executive on May 1 by Marc Bolland, former CEO of Morrisons, but will remain as a part-time non-executive chairman.
The company has said his latest possible departure date from this role will be after the annual shareholders’ meeting in July 2011.
However, speaking at a conference in London today, Rose said he would probably go “a bit earlier” adding “I’ve done this job now longer than the Second World War lasted. I am going to go at the appropriate time.”
Rose added the retailer’s board had not yet started the formal search for a new chairman, and would not say if he would take a pay cut when he moves to the part-time chairman role.
He predicted that Bolland would take M&S into new product areas and services, which could include telecoms.