Colombia's largest rebel group is calling on Denzel Washington, Oliver Stone and Michael Moore to help it reach a deal with the government on exchanging imprisoned guerrillas for rebel-held hostages, including three U.S. citizens.

The Revolutionary Armed Forces of Colombia, better known as the FARC, issued a letter made public Thursday asking the celebrities to advocate the swap to the American people.

"To the people of the United States, we ask for your always generous solidarity to pressure President Bush and his government to support a prisoner exchange in Colombia," said Raul Reyes, the chief spokesman for the FARC.

The letter was also addressed to leftist academics Noam Chomsky, James Petras and Angela Davis, as well as activist Jesse Jackson.

Calls to representatives of those addressed in the letter were not immediately returned.

The three American defense contractors, Thomas Howes, Keith Stansell and Marc Gonsalves, were on an intelligence-collecting mission when their small aircraft went down in February 2003 in Southern Colombia. They were captured by the rebels. In the letter, Latin America's largest rebel group confirmed the three were well.

"Howes, Stansell and Gonsalves are alive in our custody, treated with respect and dignity in the jungle," said Reyes. "They are the only North American prisoners alive in the world."

The FARC, listed by the U.S. government as a "foreign terrorist organization," is holding some 60 prominent hostages in all, including former presidential candidate Ingrid Betancourt, politicians and military officers. It says it will only release them in exchange for nearly 600 imprisoned rebels.

President Alvaro Uribe recently broke off preliminary negotiations after blaming the rebel group for a car-bomb in a military installation that injured more than 20 people, insisting that the hostages would be freed by military operations. The families of the kidnapped are united in opposing such rescues, fearing their loved ones will be killed in the crossfire.

Uribe later relented and said that he would be open to potential talks if the rebels gave a sign of good faith.

The guerrilla group said the Colombian government's offensive in its strongholds was jeopardizing the lives of the three hostages.

The rebel leader also promised that the group would soon send evidence the three were alive. Since being kidnapped nearly four years ago, the families have received one so-called proof of life.

The FARC's latest missive comes as one of the most famous rebels stands trial in a Washington D.C. courtroom for the kidnapping of the three.

Ricardo Palmera, better known by his nom de guerre Simon Trinidad, was captured in Ecuador in 2004 and later extradited to the United States. Another guerrilla, known as Sonia, is preparing to stand trial in Washington on charges of drug-trafficking.

The FARC insists that any exchange must include Trinidad and Sonia.

In the past six years, the U.S. government has provided $4 billion in mostly military aid to Colombia to fight the more than five-decades old insurgency and the country's enormous drugs trade.