Latest Kantar Worldpanel figures mark out Tesco as the worst performing retailer in the last quarter. Tesco's sales were down 4.5 per cent year on year in the 12 weeks to 14 September, according to the latest Kantar Worldpanel data. That widens the 3.8 per cent decline reported in the previous quarter and means its market share has now fallen to 28.8 per cent. The latest negative sales data comes just a day after Tesco admitted it had overstated its profits by £250m. The uncovering of the accounting error has led to four of its executives being suspended, with multichannel director Robin Terrell stepping up to lead the UK business as interim managing director. Tesco's share price was down 3.5 per cent to 195.77p at the time of writing, having already suffered a dramatic plunge yesterday (22 September) when the news first emerged about the profit overstatement, wiping more than £2bn from the company's market value.