An international consortium has won the rights to explore Brazil's biggest oilfield at an auction in Rio de Janeiro.
The consortium is led by the Brazilian state oil company Petrobras and two Chinese oil companies, and is backed by the firms Total and Shell.
The group made the only bid in the auction, offering the minimum share of the surplus production, the BBC reports.
Protesters clashed with security forces outside the hotel where the auction was being held on Monday.
Eleven companies had expressed interest in the Libra oilfield, but the Spanish Repsol pulled out on Monday, leaving the five winners as the only ones to present a bid.
Chinese state companies CNPC and CNOOC offered 10% each, while French oil giant Total and Anglo-Dutch Shell held another 20% stake each.
Despite the lack of other offers, Mines and Energy Minister Edison Lobao said he was "not one bit frustrated" by the contest having been won by the lowest possible bid.
Petrobras offered a 10% stake on top of the 30% it was already entitled to according to the auctioning rules.
The consortium secured the rights to explore the Libra's estimated 8 to 12 billion barrels of recoverable oil reserves for 35 years.