The Roman Catholic Church in Colombia says leftist rebels holding seven foreign tourists have agreed to release the first of the captives next week.
The ELN is Colombia's second-largest leftist rebel group
The Archbishop of Medellin, Alberto Giraldo, told the BBC the National Liberation Army (ELN) will free Spaniard Asier Huegun Etxeberria next Monday.
The government of hardline President Alvaro Uribe has said it will support the deal brokered by the church which would see the rebels release the hostages if one of their leaders, who is in jail, was present.
Four Israelis, a German and two Britons were seized along with Mr Etxeberria while hiking in the northern Sierra Nevada mountains on 12 September.
One of the Britons, Matthew Scott, escaped by jumping down a ravine and has since been reunited with his family.
But soldiers continue to scour the mountains of the Sierra Nevada for the hostages and their guerrilla captors, and so far the president has not called off the troops.
The BBC's Jeremy McDermott, in Colombia, says the release could still go wrong should troops try to effect a rescue or attack the rebels as they prepare for the handover.
Reverend Dario Echeverri, a member of the Church team mediating with the rebels, said President Alvaro Uribe had given a "green light" to their proposal.
The ELN has said it wants its jailed leader Francisco Galan to witness the release of the first hostage.
Daniel, Ortaz Ohayon, Ido Joseph Guy, Erez Altawil
Spaniard: Asier Huegun
Briton: Mark Henderson
"In general the president demonstrated goodwill toward the majority of ELN demands," said Reverend Echeverri, following a meeting with President Uribe.
The plan to release the tourists was announced by Archbishop Giraldo after talks with Mr Galan, who is held in a jail just outside the city.
The hostages will be received by a commission made up of priests from the Catholic Church, a United Nations official and two guerrilla commanders, a Church negotiator told the AFP news agency.
The United Nations said it "took seriously" the ELN's announcement to free the hostages.