Sir Francis Mackay will step down as chairman of Compass Group in February 2006.
Today's announcement comes as shareholders this week repeated calls for changes at the top of the world's largest contract caterer.
Their concern follows two profit warnings in seven months.
A city analyst said: "In a way it's what some of the shareholders wanted but it's still some time off. It's not a knee-jerk reaction to the criticism."
He added that chief executive Mike Bailey's position was now less secure due to the move. "The two of them were very close," he said.
A spokeswoman for Compass said: "Sir Francis has been chairman of Compass Group since 1999. Since the start of the year the board has been discussing an orderly succession process."
Mackay leaves his £546,000-a-year post with a pension package that was worth £14.9m in September 2004.
The group will announce its interim financial results on 18 May.