SAO PAULO – Environmentalists aided by “Avatar” director James Cameron celebrated a big win Thursday after a judge suspended bidding on construction and operation of an Amazon dam that would be the planet’s third-largest.

The ruling also resulted in the suspension of the hydroelectric project’s environmental license. It was reminiscent of 1989, when rock star Sting protested the same dam alongside Indians in an event that helped persuade international lenders not to finance it at a time when Brazil was shuddering under a heavy foreign debt.

The administration of President Luiz Inacio Lula da Silva is vowing to appeal, however. And Brazil, with government reserves of $240 billion, has such a booming economy that it no longer needs money from abroad to build the $11 billion Belo Monte dam.

Environmental groups and Amazon Indians “are incredibly energized by this decision and have renewed hope, although no one is naive,” said Atossa Soltani, executive director of Amazon Watch. “Everyone recognizes that in Brazil a decision like this could be overturned quickly, and that we haven’t won the battle yet.”

Speaking Thursday to an environmental panel in Washington, Cameron said the Belo Monte dam “is a very, very important pivotal battleground” because it will set the stage for the development of 60 more dams.

Actress Sigourney Weaver, who starred in “Avatar” and traveled with Cameron to Brazil, welcomed the dam delay. But she warned of a long fight ahead.

“We haven’t stopped it. We postponed it,” Weaver said. “There needs to be more dialogue and the indigenous people need to be included.”

Increasing international condemnation won’t reverse Brazilian policy makers’ view that the dam is essential to provide a huge injection of renewable energy, said Christopher Garman, director of Latin American analysis at the Eurasia Group in Washington.

“This dam is going to happen. It’s just a matter of when it happens,” Garman said.