US retail giant Walmart has agreed to sell its British supermarket chain Asda to two UK firms for £6.8 billion ($8.7 billion, 7.4 billion euros), they announced Friday. The Issa brothers, who run petrol stations and food outlets, have joined private equity firm TDR Capital to purchase Asda, which last year regulators blocked from merging with British supermarket group Sainsbury's. bcp/rfj/rl