It held scores of such prisoners in the late 1990s when it controlled about half the countryside but gradually released them all, never obtaining the hoped-for exchange.
Some captives were rescued. Franco-Colombian presidential candidate Ingrid Betancourt and three U.S. military contractors in 2008 were freed in a bold ruse involving Colombian soldiers posing as members of a phony international humanitarian group. But others, at least 25, died in captivity, many killed by FARC insurgents when rescuers real or imagined neared.
Among those in attendance for Monday's release was Rigoberta Menchu, the Guatemalan rights activist who won the 1992 Nobel Peace prize.
She said it is now time for Colombia's government to respond to the FARC's gesture with its own display of political willingness to attain peace.
But analysts caution that peace talks, even back-channel negotiations, could be a long time coming.
Many don't believe they could happen before 2014 presidential elections.
Vivian Sequera in Bogota, Colombia, and Frank Bajak in Lima, Peru, contributed to this report.
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