By Helen Murphy and Peter Murphy
BOGOTA (Reuters) - Colombia's President Juan Manuel Santos on Wednesday said he is ready to start peace talks with the smaller of two leftist rebel groups, the National Liberation Army, in an effort to end half a century of war in the Andean nation.
Santos' decision to engage in dialogue with the guerrilla group, known as the ELN, came after it freed a Canadian geologist this week after holding him hostage for seven months.
The ELN, which has about 3,000 combatants, has been fighting the government since 1964 when radical Catholic priests inspired by the Cuban revolution took up arms in a bid to overthrow the government.
Santos already opened peace talks with the Revolutionary Armed Forces of Colombia, or FARC, in November and though they have been turbulent at times and progressed slowly, neither side has walked away from the negotiating table.
"Hopefully we can work out the necessary procedures to start dialogue with the ELN to see if once and for all we can put an end to this conflict with the two groups involved in it," Santos said at the presidential palace.
Both groups are considered terrorist organizations by the United States and European Union.
Santos' bid to draw ELN rebels into negotiations was widely expected and the group's leaders have for months expressed interest in starting dialogue similar to that of the FARC.
While Colombians will welcome Santos' effort to bring an end to conflict in Colombia, many analysts believe it will be difficult to get talks off the ground before campaigning begins for next year's presidential election. Santos must make a decision on whether to run for a second term by November.
Talks with the FARC have already dragged on for 10 months with only partial agreement on one item on a five-point agenda.
The scion of one of the nation's wealthiest families, Santos took a political gamble when he opened peace talks with the FARC in late 2012. The rebel group has taken advantage of previous peace talks to rebuild and return to the battlefield revitalized.
The ELN has sought peace before, holding talks in Cuba and Venezuela between 2002 and 2007. Experts say there was a lack of will on both sides to agree on a final peace plan.
But this time, a 10-year military offensive, backed by U.S. funds has weakened both rebel groups, cutting their numbers and damaging their lines of communication, which may have left them more amenable to negotiating a peace agreement.
Peace with the ELN and FARC - which have both made doing business in Colombia risky - would cement huge security gains over the last decade and help attract more investment to the $330 billion economy.
Colombia, a nation of 47 million, has attracted record foreign direct investment in recent years as troops push the guerrilla groups deeper into the thick jungles.
While oil and mining companies have been able to work in more remote and dangerous areas in recent years, the risk to employees continues. Both the ELN and FARC have stepped up attacks on the infrastructure this year, hitting oil pipelines and power lines repeatedly.
(Reporting by Luis Jaime Acosta; Writing by Peter Murphy and Helen Murphy; Editing by Peter Cooney and Lisa Shumaker)