UPDATE 1-Petrobras to sell stake in Africa unit to Vitol-led group for $1.5 bln

SAO PAULO, Oct 31 (Reuters) – Brazil’s Petroleo Brasileiro SA will sell its 50 percent stake in a Nigerian oil and gas exploration venture to a consortium led by top oil trader Vitol for $1.53 billion, the latest step in the state-controlled oil company’s debt reduction drive, according to a securities filing on Wednesday. Go…