The United Nations expected the Revolutionary Armed Forces of Colombia (FARC) to consider in a constructive way Colombian President Alvaro Uribe's proposal for the humanitarian exchange, UN special envoy James Lemoyne said on Sunday.

The UN said in a statement that it values the new proposal on humanitarian exchange between the FARC and the government, which is supported by the Catholic Church and the families of the victims.

Last Thursday, Uribe proposed to the FARC that the two sides tonegotiate in the Apostolic nuncio's premises, or in an embassy in Bogota, in five days.

However, the Colombian leader rejected a FARC proposal to demilitarize an area to swap hostages for its jailed members.

An eventual humanitarian exchange deal would lead to the release of 22 politicians, 37 members of the military and three UScitizens, in exchange for 50 FARC guerrillas in Colombian prisons.

The FARC, the largest and oldest guerrilla organization in Colombia, has at least 17,000 men operating in different regions of the country.

Colombia has been plagued by a four-decade civil war, in which leftist rebels, far-right paramilitaries and government troops fight each other, killing about 3,500 people every year.