An Amazon farmer pleaded guilty Wednesday to hiring the gunmen in the killing of an American nun and was sentenced to 18 years for the slaying, which he said was ordered by two ranchers.

Amair Feijoli da Cunha, 38, told a jury the ranchers wanted Dorothy Stang killed because of her opposition to their plans to log a disputed patch of rainforest.

Feijoli said he offered money to two gunmen to shoot the 73-year-old nun on Feb. 12, 2005, at the behest of ranchers Vitalmiro Moura and Regivaldo Galvao.

Feijoli testified that Galvao told him: "Until we put an end to this woman, we won't have peace on these lands." He said Galvao told him to offer $24,000 to kill Stang. Feijoli said Moura supplied the .38 caliber revolver used in the killing.

The two ranchers have been charged with Stang's killing, but legal maneuvering has kept their cases from coming to trial. The gunmen were sentenced in December to 27 and 17 years respectively.

Wednesday's sentencing capped a daylong trial in which the jury of five men and two women rejected defense claims that Feijoli was forced to hire the gunmen by ruthless ranchers who threatened his life and to whom he owed money. Prosecutors had asked that Feijoli be sentenced to the maximum penalty of 30 years in prison.

"We couldn't ask for anything better," said David Stang, the victim's brother, who traveled from his home near Colorado Springs, Colo, to attend the trial. "This is an important piece, but there are still pieces to come we want the rancher's appeals to be decided quickly and we want them to stay in jail until they face a jury."

Stang, a naturalized Brazilian originally from Ohio, spent the last 23 years of her life in the remote jungle town of Anapu, some 1,250 miles north of Rio de Janeiro, where she defended the rainforest and poor settlers who lived there.

Stang was shot on a muddy stretch of road deep in the heart of the Amazon following a long-running dispute with ranchers over a patch of forest they wanted to log and then convert into pasture land. She wanted to have the land declared as a sustainable development reserve.

Stang's killing evoked comparisons with rainforest defender Chico Mendes, who was shot in 1988 in the western Amazon state of Acre.

Lawyers for the Stang family said it also was important to convict the men accused of ordering the killing — something that rarely happens in Para state, where ranchers and loggers are closely linked to politicians and the police.

"Up until now, the history of this region is one of impunity, where the wealthy have their way," said lawyer Brent Rushforth, who flew in from Washington D.C. to attend the trial along with the Stang's brother, David, 63, and her sisters Marguerite Hohm, 73, and Mary Heil, 77.

Hohm said she was pleased with the proceedings so far but it was essential to convict the men who ordered the killing.

"I want to see who this guy Bida is. I want to look him in the eye," she said, referring to the rancher Moura by his nickname.

CountryWatch: Brazil

Outside the courthouse, poor settlers, who traveled for days by bus over washed-out dirt roads, camped out under tarpaulins. Some held banners with Portuguese slogans reading: "Sister Dorothy your blood has cleansed the Earth."

Para is notorious for land-related violence. According to the Catholic Church's Land Pastoral, more than 500 land-related killings have occurred over the past 20 years, but only 10 cases ever went to trial.