The Revolutionary Armed Forces of Colombia, or FARC, offered last month to free two local politicians and four members of the security forces but negotiations had dragged.
Leftist Senator Piedad Cordoba said on Wednesday she had been told where the rebels would hand over the six hostages who have been held for years during Latin America's oldest insurgency.
"I already have the coordinates, the liberation is under way and the first release will take place on Sunday, and there will be three successive handovers," she told reporters.
The International Committee of the Red Cross (ICRC) is involved in coordinating the release and Brazil will provide helicopters to pick up the captives.
The planned release would be the first voluntary move by the rebels since February 2008, when Venezuelan President Hugo Chavez brokered a deal to free four kidnapped Colombian politicians with the senator's help.
It is also the first such gesture since Colombia's military dealt the FARC a severe blow in July with the daring rescue of high-profile captives Ingrid Betancourt and three Americans.
The FARC has not said why it offered to free former state governor Alan Jara, local lawmaker Sigifredo Lopez and four members of the security forces, but analysts say the group hopes to boost its battered international standing and win back lost political initiative.
Talks over how to organize the release of the six captives had stalled over logistics and the FARC demand that an international figure take part in the process.
Uribe rejected the involvement of foreign governments in the release, saying that could endanger Colombia's diplomatic ties. In the end, the rebels agreed to Senator Cordoba's offer to attend the handover along with ICRC delegates.
The Colombian government said it would halt all military operations in the area during the three separate handovers to ensure the hostages could be freed safely.
But hostage talks seem distant because FARC commanders want the government to demilitarize an area the size of New York City as a condition for negotiations.
Uribe refuses, saying such a zone would allow the FARC to regroup and strengthen its role in drug trafficking in the world's No. 1 cocaine producer.
Last Mod: 29 Ocak 2009, 17:42