Colombian rebels call for peace negotiations BOGOTA (Reuters) - Colombia's new FARC rebel leader has called on President Juan Manuel Santos to revive failed peace talks from a decade ago and help bring an end to nearly 50 years of war. Latin America's oldest insurgency movement is, however, at its weakest in years after a U.S.-funded crackdown, and Santos has made clear he will not open talks unless the rebels first give up arms, release hostages and halt attacks. Guerrilla chief Timoleon Jimenez, or "Timochenko," said his Revolutionary Armed Forces of Colombia (FARC) "would be interested in a hypothetical negotiating table" It was the latest of periodic overtures from the FARC and came in a letter published late on Monday on the group's website www.farc-ep.co/. But Timochenko did not explain what he meant by "hypothetical" or give any sign that the FARC would meet Santos' conditions, and experts doubted his letter would have any significant impact. Various peace efforts in Colombia since the 1980s have brought mixed success, with some smaller armed groups demobilizing but the FARC, the biggest rebel group in the country, has pressed on, funded in large part by the cocaine trade. Timochenko urged Santos - who was finance minister during the failed 1999-2002 El Caguan peace process where Colombia created a demilitarized zone (DMZ) for rebels - to take up the agenda left over from those talks. Guerrillas were widely seen to have used the Caguan negotiations to rearm and re-equip their ranks while right-wing elements with links to Colombia's political establishment were also accused of undermining talks. Caguan has become a symbol for some Colombians of the FARC's unwillingness to end a war that has claimed tens of thousands of lives, displaced millions more and stymied economic development and investment until a few years ago. "Caguan has become a byword for failure and though Timochenko makes no demand for a new DMZ, its very mention sets low expectations, both in government and among a public keen to see a negotiated solution," said UK-based newsletter LatinNews. Santos and his predecessor President Alvaro Uribe have pushed the FARC back thanks to improved intelligence, mobility and training of Colombian security forces. That has led to the killing or capture of senior rebels. Timochenko took over the FARC late last year after the previous chief, Alfonso Cano, was killed in one of the biggest blows to the rebels since they took up arms in the 1960s. In his rambling letter, which included references to the Bible, Greek myths and U.S. writer Jack London, Timochenko said the FARC wanted to address issues of privatization, deregulation, trade, investment, environmental degradation and military doctrine as part of the proposed peace talks. The FARC letter, titled "No Lies, Santos, No Lies," criticized the government's oil and coal policies, saying it favored foreign investors over Colombians. Since coming to power in 2010, Santos' government has pushed through a range of reforms, such as the restitution of land to displaced peasants, that were key demands of rebels in the past. Editing by Kieran Murray