Brazil's oil company, Petrobras, is at the heart of the electoral debate as the candidates propose different approaches for its future management. After 12 years of the Worker's Party (PT) in office, Petrobras' market value increased six-fold and PT candidate Dilma Roussef says she will continue using the oil revenue for education and health. The main opposition candidate, Marina Silva, said that the country should not keep increasing its dependence on oil revenue. teleSUR