Plaintiffs accuse subsidiary Texaco Petroleum Co. of dumping water laden with oil and metal salts like mercury and cadmium into Amazon rivers from 1972 to 1992 instead of reinjecting these waters into the ground.

Indians also say Texaco dumped this oily wastewater into pits that seeped toxins into the soil, damaging crops, killing farm animals and causing cancer in local communities, according to a copy of the lawsuit provided by the plaintiffs.

"We want them to give us results, a new world," Secoya Indian leader Elias Piyahuaje, one of the plaintiffs, told Reuters. "We can't keep living like worms in oil."

Texaco, which merged with Chevron in 2001, says it followed accepted procedure by treating water extracted with oil and returning it to local rivers and that the firm paid for a $40 million clean-up under an agreement with Ecuador's government.

The Texaco suit has sown fear about oil operations among many Indian communities and led locals to stage violent protests in an effort to keep foreign firms out of the jungle.

The case was first filed in the United States in 1993. But the U.S. Second Circuit Court of Appeals last year affirmed a ruling that Ecuador was a more appropriate venue.

OILY PITS

Plaintiffs show photos of tar-like pits tucked away in jungle brush and Indian children's feet blackened with crude spread on dirt roads presumably to keep down the dust.

Lawyers, who say they represent 30,000 people, allege Texaco dumped roughly 18.5 billion gallons of oil-laden water during operations and demand that the company pay for a clean-up estimated $1 billion.

Texaco entered Ecuador in 1964 with Gulf Oil to help state oil company Petroecuador develop oil concessions. In 1977, Gulf left the consortium, leaving Petroecuador with a 62.5 percent interest and Texaco Petroleum the remaining 37.5 percent.

After leaving Ecuador, Texaco says it spent $40 million to cover waste-water pits, replant cleared land and fund local infrastructure in a clean-up project that was inspected and approved by the Ecuadorean government.

The company also says it treated oil-laden water in a three-stage process before releasing it back into the environment and that reinjection was not required.

"It was an approved oil field practice. It was allowed in Ecuador as well as many other places," ChevronTexaco (CVX.N) spokeswoman Maripat Sexton told Reuters by telephone Tuesday.