(ShareCast News) - Walmart-owned Asda has appointed Sainsbury's retail and operations director Roger Burnley as its new chief operating officer.Burnley, who will take up to a year of gardening leave, will take on the role at Asda next year.Chief executive Andy Clarke said: "These are times of unprecedented turbulence for our industry. While 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."Burnley's appointment comes just weeks after Asda reported its worst-ever quarterly performance, with sales from stores open for at least a year down 4.7% in the 11 weeks to June 30.Sainsbury's said in a statement that Burnley has left the company with immediate effect and the search for his successor is underway.