Laura Wade-Gery has been appointed as executive director of multi-channel and ecommerce at Marks & Spencer.
The move indicates chief executive March Bolland's commitment to growing online sales.
The appointment comes two full years before the group's current contract with Amazon expires, and new e-tailing software can be developed for the retailer.
Wade-Gery currently heads both tesco.com and Tesco Direct and does not have a fixed date to start her new role.
Bolland said: "I am delighted that Laura is joining the executive team. Her appointment is in line with the plans we announced last November to grow our multi-channel ecommerce business both in the UK and internationally. Laura brings a wealth of relevant experience to M&S and we are all very much looking forward to working with her."