Amazon has appointed Asda’s general counsel and company secretary Alex Simpson, who advised Asda on its unsuccessful merger bid with Sainsbury’s.

Simpson, who has been at Asda for over eight years and acted as the grocer’s general counsel and company secretary since 2013, will step down from his role at the retailer on September 12.

During his time at the grocer Simpson was tasked with drawing up and offering legal advice on Sainsbury’s and Asda’s proposed merger, which went on to be blocked by the Competition and Markets Authority.

Simpson’s appointment will strengthen Amazon’s ties to the UK grocery market as it works to gain market share with its Amazon Fresh online offering, Whole Foods acquisition and the much-speculated UK launch of its check-out-free Amazon Go store format.

An email sent to Asda staff by boss Roger Burnley and seen by The Telegraph said: “I am writing to let you know that Alex Simpson, our general counsel and company secretary, has decided the time is right for him to leave us and take on a new role.

“Alex joined us almost 10 years ago and has been part of the exec team since 2013, during which time he has built and successfully led teams of lawyers and colleagues, managing some of the very complex legal challenges that we have faced.

“As general counsel, Alex has been a strong and inclusive leader and has built a professional and very capable legal team.

“He has also provided us, and Walmart, with impeccable legal judgment, a strong knowledge of the business and uncompromising integrity.”

Burnley told staff a search for Simpson’s replacement was under way.