Brazil's environmental regulator Ibama decided on Thursday to shelve the environmental license request for a hydroelectric dam on the Tapajos River in the Amazon, a project that had been opposed by indigenous tribes and conservation groups.

Ibama's licensing office ruled the dam's backers had not presented information in time to show its social and environmental viability. They halted the project, costing 30 billion reals ($9.40 billion). In April, Ibama had suspended the licensing process that began in 2009 after criticism by Brazil's indigenous affairs department, Funai.

With installed capacity of about 6.1 gigawatts, the dam proposed by state-run Eletrobras, Brazil's largest power utility holding, and a group of other electricity companies, would have been one of Brazil's biggest.