Colombia's FARC guerrilla group said Wednesday it had established some common ground with the government on sensitive land issues in peace talks aimed at ending their decades-long conflict.

The positive tone taken by rebel negotiators in Havana came in letters to delegates to the talks from Chile and Venezuela, just days after the leftist guerrilla group ended a unilateral ceasefire.

In both letters, the guerillas said they had found some common ground with Bogota on issues related to land ownership in Colombia, which they said was at the root of their insurgency, Latin America's longest.

"We sat at the negotiating table, fortunately finding areas of agreement with the government in our points of view on the situation of the poverty generated in our country by the unjust land holding structure," the FARC wrote in a letter to Chilean delegate Milenko Skoknic.

In a similar letter to Venezuela Ambassador Roy Chaderton, the FARC wrote it had presented government negotiators with its views on land ownership and land use "as a generator of misery."

"There are coinciding diagnoses pointing to this factor as the cause for the conflict that bleeds our country and needs to be overcome urgently," the FARC wrote.

Both letters were posted on the FARC delegation's blog on the talks, which began in Havana on November 19 and are the fourth attempt to end a war that began in 1964.

The government estimates that 600,000 people have been killed by armed groups and the security forces during the conflict, and some 3.7 million Colombians have been displaced.

On Sunday, the FARC announced the end of a two-month unilateral ceasefire that it had declared at the outset of the Cuba talks.