RIO DE JANIERO, Brazil: Brazil sold extraction rights to 19 oil and gas blocks near the mouth of the Amazon river Tuesday (Jun 17), at an auction slammed by environmentalists months before the country is to host a UN climate summit.

Two consortiums, one comprising Brazil's state-owned Petrobras and US giant ExxonMobil, the other US multinational Chevron and China's CNPC, spent US$153 million on exploration and production concessions for 19 blocks on offer in an area considered vulnerable to environmental harm.

They are among 172 blocks, most of them offshore, that went on auction Tuesday as dozens of protesters gathered outside the venue under a banner reading: "Stop the doomsday auctions."

Green groups have expressed particular concern over 47 blocks in the Atlantic, in an area near the mouth of the Amazon River that flows through the world's largest carbon-capturing tropical rainforest.

The first 19 blocks to which rights were sold were part of these 47.

In all, 34 blocks found takers at the auction, bringing in about US$180 million for the state.

Investments of more than US$260 million are planned for exploration.

'Cannot ignore it'

Already Latin America's biggest oil and gas producer, Brazil is seeking to increase production from 4.68 million to 5.3 million barrels per day by 2030....