The price freeze by Asda, which trails market leader Tesco TSCO.L and No. By James Davey LONDON, June 13 (Reuters) - Asda, Britain's third largest supermarket group, has frozen the prices of over 500 products until the end of August, it said on Tuesday, adding to signs that a surge in food inflation is set to abate and even reverse in the coming months. The move follows recent steps by grocers to cut the prices of items that have seen the sharpest rises, such as milk, butter, bread, pasta and vegetable oil.