Over the 12 weeks to October 4, according to the latest Worldpanel by Numerator grocery market share data, Asda sales slipped 0.5% year-on-year, leaving the grocer with 11.5% market share. At the end of August, the retailer trumpeted that it had returned to sales growth for the first time in more than two years, with Q2 total sales up 0.4% to £6.5bn.