BOGOTA, Colombia (Reuters) - Colombian guerrillas demanded the release of a top commander extradited to the United States as a key condition for freeing 63 hostages, including three Americans and a former presidential candidate.

The Revolutionary Armed Forces of Colombia demanded the release of Ricardo Palmera, alias "Simon Trinidad," who was sent to face cocaine trafficking and kidnapping charges in the United States in December, in a communique posted on its Web page, www.farcep.org, late Sunday.

The rebel army known by the Spanish initials FARC also said it wanted the government to release thousands of jailed guerrillas including senior rebels Ricardo Gonzalez and Nayibe Rojas. Rojas, known as "Sonia," is also about to extradited to the United States on drug charges.

The FARC's 63 hostages include police officers, soldiers, politicians and three civilian Defense Department contractors captured when their light aircraft crashed during a mission to locate drug crops in February 2003.

Another high profile hostage is Ingrid Betancourt, a dual Colombian-French national who was captured while running for president in early 2002.

"We will hand over the group to be exchanged if the government hands over all of the guerrillas in its power, including Simon Trinidad, Ricardo Gonzalez and Sonia," the FARC said.

A U.S. government spokesman had no immediate comment. The Colombian government made no response either.

The FARC has 17,000 fighters, funded by cocaine and kidnapping, hiding out in Colombia's jungles and mountains and staging regular attacks on government forces. Apart from their political hostages, they also kidnap hundreds of people for ransom every year.

Although polls show the rebels who started out as a peasant militia have minimal support in urban areas, their war for socialist revolution has lasted four decades and claims thousands of lives a year.

President Alvaro Uribe has taken a tough stance against the FARC and extradited Palmera after the rebels failed to release their hostages.

The rebels occasionally release videos of their hostages, looking grim in jungle camps, to pressure the government. The three Americans were interviewed in 2003 by a Colombian journalist and pleaded with the authorities not to attempt to rescue them because they would be killed.