Reuters - Brazil's Petroleo Brasileiro SA may find as much as 10 billion barrels of oil in a group of offshore exploration blocks bought from the government in an oil-for-stock swap, an official of the country's petroleum regulator said on Wednesday.

Under the swap, Petrobras bought the rights to 5 billion barrels of oil and natural gas in the areas located in the Santos Basin directly from the government in a non-competitive bidding process.

(Reporting by Jeb Blount; Editing by Jeffrey Benkoe)