Fortnum & Mason managing director Stuart Gates has resigned, citing health reasons.
Finance director Les Collins and operations director Cathy O'Neill will split Gates's duties until a replacement is found.
Gates' departure comes at an important juncture in the 300-year-old retailer's history, because last month it outlined major international expansion plans.
The first phase was the formation of Fortnum & Mason Japan (FMJ), with Japanese department store Mitsukoshi. Gates, along with Collins, was due to sit on the FMJ board, but the venture will be unaffected by his departure.
Profitability at the Piccadilly store was dented last year by the restructuring of its international business in preparation for the new overseas retail model. Fortnums believes the retail approach will be easier to control than the previous wholesale model.
Sales at the Piccadilly store are running 8 per cent ahead in the financial year to July.