Trading houses Vitol, Glencore and Trafigura are caught in the crossfire between Russian oil producers and Western buyers.
Vitol Mining News
Prosecutors said the companies bribed employees at Petrobras, as the Brazilian state oil company is known, to the tune of $15.3 million between 2009 and 2014.
Bids for Optimum are expected to be finalized by the end of November, with due diligence starting on Monday.
Greece has shortlisted Anglo-Swiss Glencore and Swiss Vitol to submit a binding bid for a majority stake in the country's biggest oil refiner Hellenic Petroleum