Sir Anthony Bamford is to stand down as the managing director of industrial digger manufacturer JCB.
JCB employs more than 5,000 people worldwide
Sir Anthony, who took over the role from his father Joseph Cyril Bamford in 1975, will continue as the Staffordshire-based company's chairman.
The firm's chief executive, John Patterson, will assume the role of MD.
JCB is the world's fifth-largest construction equipment manufacturer and employs more than 5,000 people at 13 factories throughout the world.
Sir Anthony said: "This change in responsibilities is recognition of the excellent job John Patterson has done in leading the team that has taken the company where it is today.
"It also better reflects changes in the internal management structure with the formation of a new group executive.
"However, I will still continue to be actively involved in the business on a day-to-day basis."
Mr Patterson, who joined JCB as a service engineer in 1971 before rising through the ranks, will start his new role in December.