The Red Cross received the statement “directly from the group” and waiting to be told where to pick him up, the organisation’s Colombia boss Jordi Raich announced.
Langlois, who works for RFI's sister TV channel France 24, was captured while accompanying soldiers who clashed with the guerrillas after destroying five cocaine production laboratories in southern Colombia.
The rebels declared that he was a “prisoner of war” because he was wearing a military helmet and flak jacket.
Colombian soldiers say that he was wounded in the arm during the fighting and surrendered to the guerrillas, declaring that he was journalist.
The kidnapping has aroused protests from rights groups and press freedom campaigners. Colombian journalists’ union Felcoper was among those demanding his release.
In February the Farc announced it would stop carrying out kidnappings for ransom.
In April it freed its last military and police hostages.
Olga Gomez of the Free Country Foundation estimates that the group is still holding more than 400 civilians, a charge that the Farc dismisses as biased without giving figures of its own.