BUENOS AIRES, Argentina -- Former Argentine dictator Jorge Rafael Videla was convicted and sentenced to 50 years Thursday for executing a systematic plan to steal babies from prisoners who were kidnapped, tortured and killed during the military junta's war on leftist dissenters three decades ago.

Argentina's last dictator, Reynaldo Bignone, also was convicted and received a 15-year sentence.

The baby thefts set Argentina's 1976-1983 regime apart from all the other juntas that ruled in Latin America at the time. Videla and the rest of the junta were determined to remove any trace of the armed leftist guerrilla movement that they said threatened the country's future.

The "dirty war" eventually claimed 13,000 victims according to official records. Many of them were pregnant women who gave birth in clandestine maternity wards.

Videla testified that there was no systematic plan to remove babies, and accused jailed women of using their unborn children as "human shields" in their fight against the state.

Nine others, mostly former military and police officials, also were accused in the trial, which focused on 34 baby thefts. Seven were convicted and two were found not guilty.

Witnesses included former U.S. diplomat Elliot Abrams, who was called to testify after his long-classified memo describing a secret meeting with Argentina's ambassador was made public at the request of the Grandmothers of the Plaza de Mayo, a human rights group whose evidence-gathering efforts were key to the trial.

Abrams testified from Washington that he secretly urged Bignone to reveal the stolen babies' identities as a way to smooth Argentina's return to democracy.

"We knew that it wasn't just one or two children," Abrams testified, suggesting in his testimony that there must have been some sort of directive from a high level official -- "a plan, because there were many people who were being murdered or jailed."

No such effort at reconciliation was made. Instead, Bignone ordered the military to destroy evidence of "dirty war" activities. The junta denied any knowledge of baby thefts, let alone responsibility for the disappearances of political prisoners. The U.S. government also revealed little of what it knew as the junta's death squads eliminated opponents.

The Grandmothers group has since used DNA evidence to help 106 people who were stolen from prisoners as babies recover their true identities. Many of them were raised by military officials or their allies, who falsified their birth names in an effort to remove any hint of their leftist origins.

The group estimates as many as 500 babies could have been stolen in all, but the destruction of documents and passage of time make it impossible to know for sure.

Videla, 86, received the maximum sentence as the man criminally responsible for 20 of the thefts.

He and Bignone, 84, already are serving life sentences for other crimes against humanity. They are being kept behind bars despite an Argentine law that usually permits criminals over 70 to serve sentences at home.

Others convicted and their sentences included former Adm. Antonio Vanek, 40 years; former marine Jorge "Tigre" Acosta, 30; former Gen. Santiago Omar Riveros, 20; former navy prefect Juan Antonio Azic, 14; and Dr. Jorge Magnacco, who witnesses said handled some of the births, 10.

A couple who adopted one of the babies, former Capt. Victor Gallo and his ex-wife Susana Colombo, were sentenced to 15 and five years in jail, respectively. Their adopted son, Francisco Madariaga, testified against them and said he hoped their sentences would set an example.

Retired Adm. Ruben Omar Franco and a former intelligence agent, Eduardo Ruffo, were absolved.

According to Argentine judicial procedure, the basis for the convictions and sentences won't be revealed until Sept. 17, said the president of the judicial tribunal, Maria del Carmen Roqueta.