BOGOTA, Colombia (AP) _ Three outlawed paramilitary factions agreed Friday to disarm immediately, the first sign of progress in six weeks of peace negotations with the Colombian government.

The decision speeds up the disarmament of several thousand fighters, as the paramilitary umbrella group _ the United Self-Defense Forces of Colombia, or AUC _ had previously pledged that all the group's 13,000 fighters would lay down their arms by the end of 2005.

Colombian President Alvaro Uribe hailed the announcement as ``a big step toward peace.''

The three factions include the Banana Bloc in Colombia's northwest, the Centauros bloc in the eastern Casanare region and the Northern Bloc, whose leader, Salvatore Mancuso, is also head of the AUC. Peace commission officials said thousands of fighters were in the three factions but did not have a precise number.

Peace negotiations started July 1 between the government and the AUC in the northwestern rural town of Santa Fe de Ralito, a paramilitary stronghold.

Friday's announcement failed to discuss what concessions the government was offering in return for the early disarmament.

President Alvaro Uribe's administration has said paramilitary warlords should go to jail for five to 10 years, but Mancuso has repeatedly said his group will not disarm if it means he or other leaders must accept prison terms.

The paramilitary groups were founded by wealthy ranchers two decades ago to combat leftist rebels guerillas the army has been unable to defeat in 40 years of warfare.

The country's two main rebel groups _ the 17,000-strong Revolutionary Armed Forces of Colombia, or FARC, and the smaller National Liberation Army _ have refused to declare cease-fires or join peace talks.

More than 3,000 people, many of them civilians, die in this South American nation's conflict each year.