Peter Staude will retire as CEO of JSE-listed Tongaat Hulett, with effect from October 31.
He worked for the company for 40 years and served as CEO for the past 16 years.
An interim CEO will be appointed while a recruitment process for a permanent successor is under way.
Staude has agreed to serve as an adviser to the company following his retirement.
Meanwhile, Tongaat on Monday also announced that Murray Munro will step down as CFO and executive director, effective August 7.
He will remain an employee of the company and will return after an extended medical leave of absence.
Senior finance executive Rob Aitken will serve as acting CFO.