Sainsbury's retail and operations director Roger Burnley is joining rival Asda as chief operating officer.

It has been reported that the move makes Mr Burnley one of the likely candidates to succeed current Asda chief executive Andy Clarke should he decide to step down.

He has already worked alongside Mr Clarke at both Asda and Matalan in the past.

With the main supermarket giants all struggling to contend with the rapid rise of the discount supermarkets, and Asda having recently posted its worst-ever quarterly sales figures, Mr Clarke acknowledged that Mr Burnley is joining at a tricky time.

"These are times of unprecedented turbulence for our industry," he said.

"Whilst we are not immune from the effects of this, we are fortunate to be part of a healthy, sustainable business with a clear strategy for success.

"Adding Roger to Asda's Executive team further strengthens the board which, I believe, is now one of the most experienced and capable in the industry. I am looking forward to working with him again, this time as my deputy."

A Sainsbury's spokesman confirmed Mr Burnley's immediate departure and said the search for a replacement was under way.

Sainsbury's chief executive Mike Coupe said: "I would like to thank Roger for his significant contribution to Sainsbury's over the last decade. During his time at Sainsbury's Roger has helped shape several areas of our business.

"He leaves Sainsbury's retail and operations teams in excellent shape, along with our best wishes for the future."