Qatar Holding, the investment arm of the state’s sovereign fund, is in advanced talks to buy a 49% stake in Brazilian billionaire Eike Batista’s gold company AUX for about $2bn, three banking sources said. Batista, Brazil’s richest man, said in June that he expected to sell the AUX stake, which owns gold mining rights in Colombia, for about $2bn by September. The gold firm, created in 2010, is part of Batista’s EBX holding company.