(Adds comment from Petrobras CEO, details of signing bonuses)
By Alexandra Alper and Marta Nogueira
RIO DE JANEIRO, June 7 (Reuters) - Norway's Equinor ASA led oil majors grabbing pre-salt blocks in Brazil on Thursday, snapping up stakes in some of the world's most alluring offshore geology despite fresh concerns about political meddling in the country's energy sector.
A consortium of Equinor, Exxon Mobil Corp and Petroleos de Portugal made Thursday's most aggressive play, offering more than three times the minimum bid for the Uirapuru block in the Santos Basin off the coast of Rio de Janeiro.
That meant partnering with Brazil's state-run oil company Petroleo Brasileiro SA, or Petrobras, which joined all three winning consortia in the round.
Brazil's cash-strapped government collected 3.15 billion reais ($800 million) in fixed signing bonuses at the auction.
The world's leading oil producers have been spending top dollar to lock up access to Brazil's coveted offshore, seeking to replenish depleted reserves as oil prices rise. Billions of barrels of oil are in the Brazilian pre-salt, beneath a thick layer of salt under the ocean floor.
Unexpected changes to diesel pricing in Brazil last month raised questions about renewed political interference at Petrobras and triggered the surprise exit of Chief Executive Officer Pedro Parente, who had turned the company around.
Yet Thursday's auction, including winning bids from Chevron Corp, BP Plc and Royal Dutch Shell Plc, underscored enduring appetite for Brazil's offshore despite any meddling in Petrobras' downstream business.
"We didn't really make a connection with the fuel prices and the bidding rounds. It is quite an independent process," said Anders Opedal, country manager for Equinor, which changed its name from Statoil last month.
Ivan Monteiro, speaking as Petrobras CEO for the first time since being appointed on Friday, said the company would keep seeking to boost its exploration portfolio.
Petrobras, Equinor, Exxon and Petroleos de Portugal won the Uirapuru block by offering the government 75.49 percent of oil after covering costs - well above the 22.18 percent minimum bid.
The Uirapuru block is near the North Carcara area, which the same consortium clinched in an October round. Opedal said it was too soon to say if the blocks would be developed jointly.
Equinor also won rights to develop the Dois Irmaos block of the Campos Basin, along with BP and Petrobras.
Exxon, one of the few oil majors without stakes in Brazil's world class pre-salt geology until late last year, has stakes in 25 Brazilian blocks after Thursday's win.
$1 = 3.9323 reais Reporting by Alexandra Alper and Marta Nogueira; Additional reporting by Rodrigo Viga Gaier; Writing by Brad Haynes; Editing by David Gregorio and Cynthia Osterman