The Colombian Government has been holding secret talks with the country's largest right-wing paramilitary groups in an attempt to set up possible peace negotiations, officials have revealed.

Uribe: Ceasefire essential before negotiations

The revelation follows a Colombian magazine article which said that the government's peace commissioner, Luis Carlos Restrepo, had met leaders of the United Self-Defence Forces of Colombia (AUC) following mediation by Catholic bishops.

Cardinal Pedro Rubiano, president of the Colombian Bishops Conference, said that the AUC had asked bishops to set up the meetings in areas where the group is active, the Associated Press reported.

AUC leader Carlos Castano reportedly agreed to call a two-month ceasefire - commencing 1 December - as a goodwill gesture, according to local media.

Reports say he could announce the move formally in the next few days.

Such negotiations could lead to the demobilisation of the AUC's 9,000-strong force and an amnesty for militia leaders.

Ending conflict

Correspondents say a ceasefire could also lead to a dramatic shift in the balance of forces in the country, where about 3,500 people, mostly civilians, are killed every year by fighting between Marxist rebels, right-wing paramilitaries and government forces.

Paramilitary groups were formed to combat left-wing guerrillas

Interior Minister Fernando Londono acknowledged that "contact" had taken place between the two sides.

But he added that Colombian President Alvaro Uribe "reserved the right to handle the process", French news agency AFP reported.

Mr Uribe's hardline government has said that although it is open to talks with any armed group a ceasefire is a firm pre-condition for negotiations to end the country's bloody 38-year civil conflict.

However, the BBC's Jeremy McDermott in Colombia says there are fears that if the paramilitaries disarm and abandon the large swathes of the country currently under their control they will simply be replaced by their guerrilla enemies.

Colombia's security forces, they say, do not have the strength to occupy the disputed areas.

"If the paramilitaries take this step and the others don't, we will see a massacre of Colombians," Cardinal Rubiano said.

US indictment

The AUC was ostensibly formed to eradicate Colombia's Marxist guerrillas such as the Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN).

Funded by drug money and suspected of links to hardliners within the Colombian army, they have carried out some of the most appalling massacres of suspected left-wing guerrilla sympathisers, politicians and journalists.

Their leader - Mr Castano - was recently indicted by the US State Department on charges of smuggling cocaine and is being sought for extradition by US authorities.

He has already been sentenced in absentia by Colombian authorities to serve 22 years in prison.