Iran has formally invited Brazil to join the 13-member oil producrts cartel – OPEC. Iran's ambassador Moshen Shaterzadeh made the formal invitation during a meeting with Brazilian energy minister Edson Lobao.

Iran, with one of the largest oil reserves in the world, is a founder-member of OPEC and can propose another country for membership.

Brazil attracted global attention last year when it announced that it had discovered the second-biggest oil find in 20 years in the Tupi basin - an area 800km (500 mile) by 200 km (125 mile) wide --- off Brazil's southern coast that analysts say may contain a massive 5 billion to 8 billion barrels of untapped light oil.

Subsequently, other finds in the Santos Basin suggest Tupi's find may be just the tip of a huge reservoir of light crude. The problem now for Brazil is to extract the oil from the Tupi basin, located seven kilometers under the waves, under a salt layer one kilometer thick.

If confirmed by tests which are underway, those finds would increase the country's proven national oil reserves, which currently stand at 14 billion barrels, and propel Brazil to the same level as OPEC members Nigeria or even Venezuela.

Petrobras, the state-owned oil company's engineers has put the Tupi find at an estimated 20 trillion dollars on an estimated reserve of more than 100 billion barrels of oil at a market price of $200 a barrel of crude.

However, President Luiz Inacio Lula da Silva has said that Brazil wold not be an exporter of crude but an exporter of high-value petroleum derivatives. Brazil will invest around $100 billion on new refineries including those capable of producing high-quality diesel and petrol for the export markets.

Speaking to reporters, energy minister Lobao said Brazil is yet to respond to Iran's invitation and was still evaluating the offer, though said he saw no obstacles to his country becoming a member of OPEC even though it is not yet a major oil exporter.

Lobao said that last May, at Saudi Arabia's invitation, he attended an emergency OPEC meeting at which he outlined the perspectives for Brazil's oil industry. He said that the fact Brazil was invited for an emergency meeting indicated that OPEC intended to invite it to join the group, if not now, then in the short run.

According to Lobao OPEC members believe Brazil will become one of the world's largest oil producers. Discussions about Brazil's possible OPEC membership began months ago, after Brazil's massive oil find in Tupi.

Analysts say that up to 600 billion dollars worth of investment in research, logistics and technology are required to extract the oil below a thick layer of salt at depths of up to 7,000 meters (23,965 feet) under Brazil's Atlantic waters.

Brazil is now revamping its defense policy and armed forces capabilities on the escalating problem of protecting the recently discovered massive off-shore oil reserves.

Brazil's Defense minister Nelson Jobim said his government would be spending about $160 million by the end of next year on the development of a nuclear-powered submersible developed with Brazilian technology and French assistance to protect the new found oil reserves.