Steve Rowe will step down as chief executive of Marks & Spencer in May after six years in the job.
Mr Rowe, who joined M&S at the age of 15 before rising through the ranks, will step down after the food and clothing retailer reports annual results on May 25.
After a turbulent tenure in one of the most high profile jobs in British business he will exit as hopes are rising that one of the country's most elusive turnarounds could finally materialise after more than a decade of false dawns.
M&S said current joint chief operating officers, Stuart Machin and Katie Bickerstaffe, will take over Rowe's responsibilities in an unconventional structure.
Mr Machin will become CEO and will take on responsibility for day-to-day leadership of the business and the executive committee.
He will continue to have oversight of his current portfolio of responsibilities, which includes the leadership of M&S's food business, as well as operations, property, store development and technology.
He will take on responsibility for human resources and corporate communications.
Ms Bickerstaffe will become Co-CEO with a particular focus on driving M&S' strategy of selling across multiple platforms.
She will retain her existing portfolio including responsibility for clothing & home, MS2, international and financial services.
Both Mr Machin and Ms Bickerstaffe will join M&S's PLC board on May 25.
The retailer, which is chaired by Archie Norman, has also promoted chief financial officer Eoin Tonge to chief strategy & finance officer. It said he will play an enhanced role in leading the future development of the business.
Rowe will cease full-time employment after M&S's annual shareholders' meeting on July 5 but remain an adviser for up to a year.
Shares in M&S were down 1% at 1507 GMT.