By Jeff Fick, Paul Kiernan and Luciana Magalhaes

RIO DE JANEIRO--Brazil sold the rights Monday to develop a huge oil field to a consortium of five companies in a boost to the government's state-heavy strategy for developing its newfound oil wealth.

The sole bidder at the auction was a consortium made up of many flavors. It included two private-sector firms, Royal Dutch Shell PLC and Total SA; two Asian state-owned companies, CNOOC Ltd. and China National Petroleum Corp.; and Brazil's state-owned Petroleo Brasileiro SA, or Petrobras, which, as determined by new legislation, will lead the consortium's operations.

The companies will be responsible for providing the financial muscle to develop Libra, a huge oil reserve that lies deep below the Atlantic Ocean seabed off Brazil's southeast coast. The field is estimated to contain between eight billion and 12 billion barrels of oil, and the government has proclaimed it could generate $1 trillion in public revenue over 30 years.

The consortium's bid was to give 41.95% of the oil production from Libra to the government, the minimum amount set by the state before the auction.

Critics argue that the lack of any more bidders reduced competition and detracted from the auction's success.

Magda Chambriard, director of Brazil's oil regulator, the National Petroleum Agency, called the auction a success, as five of the top 10 oil companies in the world will now develop the field. Ms. Chambriard said it was "hard to be sad" with the outcome. There was a degree of competition in the creation of the consortium, she said.

This is the first field to be developed under new legislation that put Petrobras in charge of developing Libra. Petrobras' new partners will mostly be required to put up the money, although they will also have some say in the field's development program.

The challenges are enormous in terms of the scale of the operation, the exploration work still to be done and the environmental risks of operating in the harsh conditions. The winning consortium will have to spend an estimated $200 billion over 35 years to pump oil out of a reservoir buried under the thick layer of salt beneath deep Atlantic waters.

"We look forward to applying Shell's global deep-water experience and technology, to support the profitable development of this exciting opportunity," said Peter Voser, chief executive of Royal Dutch Shell, in a statement.

All told, 10 foreign companies and Petrobras had registered for the auction. Many large foreign companies had stayed away, which analysts attributed to the prominent role that will be played by the Brazilian state in development of the oil field. Around 80% of the total proceeds from the field will go to the Brazilian government, according to the ANP.

As oil industry executives gathered in the calm atmosphere of the upscale beachfront hotel in the Barra da Tijuca district where the auction was held, a few hundred protesters gathered earlier in the day a few blocks away to try to halt the proceedings. The demonstrators see the sale as relinquishing control over the country's oil wealth, and the activists, which included labor unions and student groups, waved flags and shouted slogans.

The protest quickly escalated into a confrontation in which the police fired tear gas and rubber bullets, while some protesters threw rocks. Many peaceful protestors then left, although around 80 people remained, according to the defense ministry, taunting the cordon set up by police and army troops two blocks from the hotel.

They set small trash fires and at one point overturned a car and set it ablaze. A fire engine moved in to extinguish the fire and the car was removed.

About one block behind the first cordon was a second, more fortified security barrier. Two trucks with water cannons idled behind police lines and just a hundred yards or so off the beach, two Navy patrol boats bobbed up and down in the surf.

"All this is because we don't want to hand over our oil," said Silvio Sinedino, 62, president of the Association of Petrobras' Engineers. "They don't have any arguments, they just have bullets."

Protests have been a regular feature in Brazil since June, when millions of Brazilians turned out onto the streets to protest a variety of social problems. While protests have died down in much of the country, they have remained a frequent, often violent, occurrence in Rio de Janeiro.

The government has said that a large part of the oil wealth will be set aside for a special fund that will invest in education and health care, two of the protesters' biggest concerns.

Standing at the barricade, Vitor Zanon, 21, said he would stay all day to try to stop the auction, and that he considers the day a chance for Brazilians to show their political power. The government wants to sell the field "at gunpoint" without considering what people think, he said.

--Matthew Cowley in Sao Paulo contributed to this article.

Write to Jeff Fick at jeff.fick@wsj.com, Paul Kiernan at paul.kiernan@wsj.com and Luciana Magalhaes at luciana.magalhaes@wsj.com

Galp Energia Sgps (EU:GALP)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Galp Energia Sgps Charts.
Galp Energia Sgps (EU:GALP)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Galp Energia Sgps Charts.