* Release may help ELN in bid for peace talks
* Braeval no longer mining near site of kidnapping
* Colombia receiving record investment in mining
By Helen Murphy
BOGOTA, Aug 27 (Reuters) - Colombia's ELN rebels freed a Canadian geologist they had held captive for seven months on Tuesday, meeting one of the demands by President Juan Manuel Santos to enable the start of peace talks with the insurgent group.
Jernoc Wobert was seized on Jan. 18 in northern Bolivar province along with two Peruvian and three Colombian miners contracted by the Toronto-based Braeval Mining gold mining company. His colleagues were later freed by the leftist ELN, or National Liberation Army, the smaller of two rebel groups fighting the government for almost five decades.
Wobert was released in a rural area to a mission of the International Committee of the Red Cross and has been examined by a doctor, said ICRC spokesman Jordi Raich in a statement.
Santos has conditioned any peace talks with the ELN on freeing Wobert and all other captives it holds in the nation's jungles. ELN leaders have expressed interest in starting peace negotiations similar to those currently under way with the Revolutionary Armed Forces of Colombia, or FARC.
It is not known how many hostages the group holds.
"We hope that this effort contributes to a healthy exchange and support for peace in Colombia," ELN leader Nicolas Rodriguez said in a video posted on the group's website. He said the release was a humanitarian gesture.
The ELN, which is against mining by foreign companies in Colombia, pledged to free Wobert after Toronto-based Braeval said last month it would no longer mine in the area where he was kidnapped. The company did not link the decision to Wobert's capture.
Efforts to rid Colombia of its reputation as one of the most dangerous places to do business has led to a rush of investment into areas that were once off-limits.
Colombia, a nation of 47 million people, has attracted record foreign direct investment in recent years as troops push the guerrilla groups deeper into inhospitable 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.
The ELN has battled a dozen governments since it was founded in 1964 and is considered a terrorist group by the United States and the European Union.
Inspired by the Cuban revolution and established by radical Catholic priests, the ELN was close to disappearing in the 1970s but gradually regained strength. By 2002 it had as many as 5,000 fighters, financed by "war taxes" levied on landowners and oil companies.
The ELN is now believed to have about 3,000 fighters. It has sought peace before, holding talks with the Colombian government in Cuba and Venezuela between 2002 and 2007. Experts say there was a lack of will on both sides to agree a final peace plan.