Supermarket giant Walmart has entered into an agreement to sell UK grocery chain Asda to Issa Brothers and TDR Capital for £6.8 billion ($9.1 billion). The acquisition will return the chain to UK ownership following its acquisition by Walmart for £6.7 billion ($8.9 billion) in 1999. According to sources, the new owners joined together to acquire an equal ownership stake in Asda, and they intend to invest more than £1 billion ($1.3 billion) …