Brazil's top three retail groups [CBD, Wal-Mart, Carrefour] have decided to ban the purchase of beef originating in deforested areas of the Amazon, the country's supermarkets association (Abras) said on Friday…The decision…came after environmental group Greenpeace published a report showing that the beef industry is the largest single driver of Amazon deforestation…[the companies] will [also] demand documents from slaughterhouses related to the transit of the cattle…[and] intend to conduct an independent audit to assure that meat that they buy is not from deforested areas.