BOGOTA, Colombia (Reuters) -- Colombian government officials said Wednesday they remained fully committed to opening peace talks with the country's leading Marxist rebel group in a demilitarized zone to be set up by early November.

In an open letter to Manuel Marulanda, the veteran commander of the Revolutionary Armed Forces of Colombia (FARC), the government said the talks should take place without any preconditions.

And it stressed the need for government and rebel leaders alike "to pass from rhetoric about peace to acts of peace" as quickly as possible, to end a conflict that has taken at least 35,000 lives over the last decade.

The letter was signed by Victor Ricardo, President Andres Pastrana's specially appointed "high commissioner for peace" and one of his closest advisers.

It responded to a missive from Marulanda that the government received over the weekend, in which the rebel chieftain proposed swapping 245 security force members held captive by the FARC for an unspecified number of rebels held in Colombian prisons.

Marulanda, whose real name is Pedro Antonio Marin, insisted that the exchange take place before peace talks get under way.

Ricardo did not rule out the possible exchange. But he repeated the government's line that it cannot consider any trade until Marulanda provides a list of the rebel prisoners he wants released.

As many as 2,000 FARC rebels are said to be serving time in 167 prisons and jails across Colombia.

Keeping a promise

Ricardo accompanied Pastrana on a trip deep into Colombia's jungle, about a month before he took office on August 7, to meet Marulanda and set the terms for negotiations with the FARC.

It was at that meeting that Pastrana agreed his administration would formally open talks with Marulanda within his first 90 days in office. He also agreed to order a troop pullout from a Switzerland-sized area of southeast Colombia, to set the stage for the negotiations.

Ricardo reiterated those commitments in his letter to Marulanda and said the government had a "sincere intention" of carrying the peace process forward.

Striking a conciliatory note, he did not refer to recent remarks by Marulanda's top military commander, who infuriated many by denying that the FARC held any civilian kidnap victims.

But Ricardo said a successful peace process would allow both the government and the FARC "to restore tranquillity to all (Colombian) homes, by permitting the return of all the people held captive today."

The FARC, Colombia's largest and oldest guerrilla force, has long relied on kidnap ransoms to help finance its war effort. A government official told Reuters on Tuesday that the group was holding 45 civilian kidnap victims, although some private estimates are even higher than that.

The government's negotiations with the FARC would be the first since an earlier round of talks broke up amid mutual deep distrust and accusations of ill will six years ago.

Copyright 1998 Reuters Limited. All rights reserved.