Authorities shut down an important deep-water Amazon River port owned by Cargill Inc. on Saturday, saying the huge U.S. agribusiness firm failed to provide an environmental impact statement required by law.

The move by federal police and environmental agents to close Cargill's controversial soy export terminal was a major victory for environmentalists in Santarem, a sleepy jungle city about 1,250 miles northwest of Sao Paulo. It came after a late Friday ruling by Judge Souza Prudente, police and the Agencia Estado news service said.

"It was peaceful," federal police agent Cesar Dessimoni said of the shutdown. "They can appeal the ruling, but no one resisted."

Dessimoni said Minnetonka, Minn.-based Cargill had prepared an environmental assessment that did not meet federal standards.

"They'll have to do it correctly, as the law demands," he said by telephone from Santarem.

Environmentalists who point to soy farming, logging and cattle ranching as the primary threats facing the Amazon praised the closure, calling it a milestone in attempts to push the government to more effectively police a region where lawlessness often prevails.

"A big step forward has been taken in enforcing the responsible use of natural resources and bringing greater governance in the Amazon," Paulo Adario, Greenpeace Amazon Campaign Coordinator in Brazil, said in a statement.

Cargill, which has operated in Brazil since 1965, said Saturday that it plans to appeal the ruling and that it had submitted an environmental impact statement that was accepted by the Amazon state of Para, where Santarem is located.

"We find ourselves caught in a jurisdictional dispute between the state and federal government about which regulations have precedence," Cargill spokeswoman Lori Johnson said. "When we built the facility, the permits were issued by the state.

"Since that time the federal prosecutor has said we should have done another kind of environmental assessment and that is the issue before the courts."

No ships were being loaded or waiting to load when the port was closed, Johnson said.

Cargill opened the $20 million port in Santarem three years ago to cash in on the rising global demand for soybeans, Brazil's most lucrative agricultural export.

The port's location puts it in a key spot if Brazil's government follows through on promises to pave a muddy jungle road, turning it into a modern two-lane toll highway stretching 1,100 miles from Brazil's top growing soy state of Mato Grosso to Cargill's deep-water port.

Johnson said Cargill has not taken a position on the road paving project and that the port can still be profitable without the road.

But grain analysts say paving the road would benefit soy exporters and Cargill by drastically cutting the cost of shipping soy abroad because many farmers could avoid sending their beans on trucks to Atlantic Ocean ports much farther away. President Luiz Inacio Lula da Silva pledged the paving would start soon during his successful campaign for re-election last fall.

Cargill became a target for residents, activists and federal prosecutors who called the port illegal and tried to shut it down. But the port also has strong support from many in Santarem, who see it as a key element for economic development to rid the region of grinding poverty.

The rain forest, as big as Western Europe, lost 6,450 square miles to deforestation between 2005 and 2006, a decrease of 11 percent from the year before, Brazil's Environment Ministry says.

Environmentalists say deforestation has slowed largely because the price of soybeans has declined on the international market and Brazil's currency has strengthened against the dollar, making it much less profitable for now to cut down the rain forest to plant grain.

The rain forest covers 60 percent of Brazil. Experts say as much as 20 percent of its 1.6 million square miles has already been destroyed by development, logging and farming.