By JUAN FORERO
 
BOGOTÁ, Colombia, Aug. 2 —- President Álvaro Uribe is prepared to cede a second safe haven to two paramilitary factions in southern Colombia as long as the groups declare an immediate cease-fire and begin disarming, his office announced today.

The offer came six days after three top paramilitary commanders, who are involved in fragile talks with the government in a northern haven created in May, vowed in an extraordinary visit to Colombia's Congress that they would never go to jail as part of negotiations.

Mr. Uribe, whose two-pronged strategy for pacifying the country calls for co-opting right-wing death squads and battling Marxist rebels, called on two rival factions to end a bloody, internecine conflict over cocaine or face an end to troubled talks with his government.

As an incentive, the government is prepared to create a second haven and possibly a third, so that the two groups have a secure zone to disarm and hold talks, said Martha Martínez, a spokeswoman for Mr. Uribe's peace commissioner, Luis Carlos Restrepo.

The government's announcement drew admonishment from some political analysts, who say the peace talks are deeply troubled because the government cedes ground but has not pushed the paramilitaries to stop their violence or admit to their crimes.

"This process is in a crisis of credibility," said Daniel García-Peña, a former peace commissioner here. "The president has time to rescue the process if the conditions are well established and they make them comply. But the government has hard rhetoric one day, and they make concessions the next."

One of the groups, the Centauros Bloc, led by Miguel Arroyave, has had a role in peace talks now being held in Santa Fe de Ralito in northern Colombia, where 10 commanders from the United Self-Defense Forces of Colombia are discussing demobilizing if the government extends leniency for mass murders and drug trafficking. The second group, the Peasant Self-Defense Forces of Casanare, led by Martin Llanos, has embarked on its own talks with the government.

"We're talking about two more zones or that the Centauros group will concentrate in Santa Fe de Ralito," said Ms. Martínez. "It is a given there will be at least a zone for Llanos."

On Friday, Mr. Llanos met with Mr. Restrepo, the peace commissioner, and told him that a zone was needed for talks to take place. In their visit to Congress last Wednesday, Salvatore Mancuso, a leading commander, also called for more safe havens around Colombia, where paramilitary commanders and troops would be shielded from arrest and extradition to the United States on drug-trafficking charges while they negotiate.

Mr. Uribe is clearly open to creating the zones to further talks, but under the condition that paramilitary groups cease hostilities. Though informal talks with various factions have been going on all year, the groups have not stopped assassinating labor leaders and human rights workers, killing peasants and trafficking in cocaine.

In the government's statement today, Mr. Uribe directed his ire at Mr. Llanos and Mr. Arroyave, saying, "If these conditions are not met in the coming days, the national government will end the peace process with these two groups."

The paramilitaries were started more than 20 years ago by rogue military officers, landowners and drug traffickers to erode support for leftist rebels by killing their supporters and taking back territory. They quickly morphed into drug-running outfits, and several paramilitary commanders are now wanted in the United States on drug-trafficking charges.