BRASILIA (Reuters) - Brazil's federal police on Friday raided the headquarters of Latin America's largest independent investment bank, Banco BTG Pactual SA (SA:BPAC3), and the addresses of its founder Andre Esteves, federal prosecutors said in a statement.
Maria das Gracas Foster, former chief executive of Brazil's state-controlled oil company Petroleo Brasileiro SA (SA:PETR4) was also a target, the statement said. The raids were related to the sale of stakes in African oilfields to BTG Pactual, it said.
BTG Pactual did not immediately comment on the matter.
Shares of the bank sank 15% in premarket trading.
Prosecutors are investigating whether Petrobras, as the state-run company is known, sold stakes in Nigerian oilfields to BTG in 2013 for a value lower than the initial assessments by other financial institutions.
"In the beginning of the sale process, the assets were valued between $5.6 billion and $8.4 billion. But in the end, BTG Pactual paid $1.5 billion for a 50% stake," the statement said. It also mentioned potential bribes related to the acquisition of oil rigs.
Petrobras sold its 50% stake in Petrobras Oil and Gas BV, known as Petroafrica, to Vitol SA last year. BTG kept its stake.
Founder Andre Esteves last month asked the central bank to allow him to take back a key stake in the bank's controlling partnership after he was acquitted on different corruption charges.