Asda has chosen Roger Burnley, the supermarket's chief operating officer, as its new chief executive.
Burnley will take over from current chief executive Sean Clarke on 1 January next year.
He returned to the business in 2016 after working in a variety of roles for Sainsbury's from 2006 onwards.
Clarke said he was "taking some time out" but that he would remain connected to the Walmart-owned grocer.
Burnley said: "Asda is a great business and we've started to realise its potential again. Sean's focus on serving customers and simplifying the business has established a firm foundation on which we can build.
"Since I returned to Asda last year, I have been encouraged by the passion and professionalism of our colleagues and look forward to leading this terrific team."
Dave Cheesewright, chief executive of Walmart, said: “Roger was purposefully brought back to Asda to partner with Sean ahead of the transition to Roger taking up the position of CEO. He and Sean have worked as a great team and I’m really confident in Roger’s ability to continue building upon our returning momentum."