RIO DE JANEIRO, June 7 (Xinhua) -- Brazil's government on Thursday raised 3.15 billion reals (about 807 million U.S. dollars) by auctioning off three pre-salt oil blocks in deep waters off the Atlantic coast.

Had the National Agency of Petroleum, Natural Gas and Biofuels (ANP) succeeded in selling off four oil blocks, as the auction intended, it would have raised a total of 820 million U.S. dollars.

Together, the four blocks are estimated to contain some 5 billion barrels of crude.

Brazil's state-owned oil giant Petrobras lost its bid on two blocks to foreign oil firms, however the company exercised its preemptive right, granted by law, by acquiring a 30 percent stake in the winning consortiums.

Investment in the blocks is estimated to reach a minimum of 738 million reals (about 190 million U.S. dollars).

"It was an extremely successful auction, in which we succeeded in attracting competitivity and raising the revenue generated," the ANP's president, Decio Oddone, said.

The blocks are expected to add 40 billion reals (about 10.2 billion U.S. dollars) to the coffers of the federal, state and local government, he said.

The gigantic reserves could turn Brazil into one of the world's biggest exporters of crude.