Machin will continue in his role as managing director of food but also take oversight responsibility for operations, property, store development and IT.
In addition, Bickerstaffe will give oversight to the data, services, clothing and home and international businesses.
Three years ago, Steve Rowe, CEO of M&S, set out the need to “face the facts” about the challenges facing the retail group and a “three-phase transformation programme”, which began with “Fixing the Basics”.
Since then, there have been “far reaching changes” in how the business is organised, its people and culture, the shape of the store estate, use of technology, and improvements in product and value to broaden appeal.
As a result, the business is now moving on from the “Fixing the Basics” phase to reinvest in the brand and restore growth. In line with the announcement, the group also revealed that Eoin Tonge will take on strategy and transformation planning as part of his remit as CFO.
Sacha Berendji moves from his current operations role to focus on “Future Stores” and accelerate the development of the “10X digital stores, store renewal, store rotation and IT”.
Richard Price and Paul Friston will remain as managing directors of clothing and home and international respectively.
The executive committee will also continue to operate as the business’s central decision-making body with its membership is unchanged.
Rowe said: “Over the last three years we have built a great team of people at M&S and covered a lot of ground.
“Now we need to move into the next phase, and that means accelerating the pace of change, and Stuart and Katie will bring even more impetus to our core businesses. With that I will, with Eoin’s support, be better able to concentrate on building the M&S of the future and our path to growth.”