By Hugh Bronstein BOGOTA, Sept 16 (Reuters) - Efforts at freeing hostages held by Colombian rebels were stalled over the weekend when neighboring Venezuela scrapped plans for talks to be held in Caracas aimed at clinching prisoner exchange. Leftist Venezuelan President Hugo Chavez, asked by Colombia to facilitate hostage swap talks, said rebel leader Manuel Marulanda would not attend negotiations in Caracas. Instead Chavez urged conservative Colombian President Alvaro Uribe to pull troops from the southern town of San Vicente del Caguan to clear the way for talks, an idea Uribe quickly rejected. The deadlock leaves the fate of hostages such as French-Colombian politician Ingrid Betancourt in limbo. "If it is true that Marulanda is not going to go to Caracas it is very bad news for the hostages because everyone knows Uribe is not going to demilitarize Caguan," said Gustavo Duncan, a Bogota-based security analyst. San Vicente del Caguan was the site of a failed peace initiative under which Colombia's previous president ceded a Switzerland-sized piece of territory to the rebels. Hard-liner Uribe fiercely criticized those talks in his first presidential campaign and won a second term last year based on his military crackdown on the Revolutionary Armed Forces of Colombia, or FARC, which has been leading a communist insurrection since the 1960s. The FARC is holding dozens of high profile hostages such as Betancourt, taken during her 2002 presidential campaign, and U.S. defense contractors Thomas Howes, Keith Stansell and Marc Gonsalves, captured during a drug-eradication mission in 2003. "Our hopes were tied to the idea of talks in Caracas," Mariana Howes, wife of Thoman Howes, told Reuters. "It is hard to tell if the FARC is serious about an exchange, because they always seem to come up with a reason for not advancing the negotiations," she said by telephone from Florida. Chavez, who says socialism can unite South America against what he calls U.S. imperialism, is on a campaign to increase his influence in the region. But his appeal to demilitarize Caguan did not go over well with Bogota. "It is a mockery to propose the impossible," Colombian Interior Minister Carlos Holguin told Reuters.
