An oilfield off the coast of Rio de Janeiro could contain 33bn barrels
Brazil has turned down an invitation to join the oil producers' cartel, Opec, according to the country's energy minister, Edison Lobao.
He told a local TV station that Brazil had been formally invited to join Opec by Iran two weeks ago.
However, he said that Brazil had declined the offer, saying his country has "other priorities".
Brazil says the recent discovery of massive offshore oil fields could turn the country into a major oil exporter.
Mr Lobao said that the invitation had come from Iran's ambassador to Brazil, Mohsen Shaterzadeh.
Although Brazil will not be taking up the ambassador's invitation, Mr Lobao did not rule out joining Opec at some point in the future.
In April, the head of Brazil's National Petroleum Agency said an oil field offshore from Rio de Janeiro's coast could contain 33 billion barrels.
That finding came after state-owned Petrobras said the offshore Tupi field was estimated to hold between five billion and eight billion barrels of untapped light oil.