The management of the consortium building the giant Belo Monte hydroelectric dam in the heart of the Brazilian Amazon initiated talks Monday with the indigenous people who have been occupying the work site since June 21.

The negotiations are expected to continue into Tuesday, a spokesperson for Norte Energia told Efe.

Work at the Pimentel site has been shut down since last week "for safety reasons," the spokesperson said.

The roughly 300 Indians occupying the site sent a letter Monday to Brazilian President Dilma Rousseff demanding that she revoke the permit for the dam and respect the right of the indigenous peoples to decide the future of the project.

The 11.2 GW dam complex on the Xingu River would be the world's third-largest after China's Three Gorges and Itaipu, jointly operated by Brazil and Paraguay.

Environmentalists and indigenous protesters say the dam will flood 516 sq. kilometers (200 sq. miles) of jungle, displace 50,000 people and cause severe damage to the local ecosystem.

Brazilian officials insist the Belo Monte dam is necessary to keep pace with the country's burgeoning energy needs.

Work on the $10.6 billion project, which began in March 2011 near the city of Altamira in Para state, has already harmed water quality in the Xingu River, the Indians said in their message to Rousseff.

The Xingu has grown "cloudy and unhealthy," making the river unsuitable for bathing or washing clothes and forcing indigenous people to hike great distances to find suitable drinking water, the letter said.

The Belo Monte project has faced legal challenges from environmentalists, indigenous people and even Brazilian government prosecutors, and the Inter-American Human Rights Commission went so far as to urge Brazil to suspend the initiative. EFE