Petrobras says on its website Monday that the head of its board of directors has already nominated a replacement for CEO Sergio Gabrielli.
The statement says Brazil's Energy Minister Maria Silva Foster was nominated to take the top spot in the oil company.
Her nomination must be approved by the board of directors when it meets Feb. 9.
It was not made clear when Gabrielli would leave.
Gabrielli is expected to enter politics in his home state of Bahia, in Brazil's northeast.
Under Gabrielli's watch, Petroleo Brasileiro SA has made massive discoveries off Brazil's southeastern coast, which likely hold more than 50 billion barrels of oil.
