Colombia's National Liberation Army (ELN) guerrilla group on Sunday released agronomist engineer Leon Andres Montes Ceballos who was kidnapped on July 30, 2012, the International Committee of the Red Cross (ICRC) confirmed in a statement.

The 33-year-old engineer was released in a rural area of Colombia's northwestern Antioquia department, The ICRC said.

The hostage was handed over to a humanitarian mission led by Dario Monsalve, the archbishop of Cali, and Francisco de Roux, the Jesuit community director in Colombia.

"We are highly pleased to have contributed to ending the suffering of this family and facilitating their reunion after such a long wait," said Director of the ICRC sub-delegation in Medellin Gregoire Castella, adding Montes was in good health condition.

Castella also said that this year, the ICRC has served as an intermediary for the release of 24 kidnapped people.

The rebel group had promised to release the engineer once Compania Agricola La Sierrathe, a Chilean timber company he worked for, would leave Colombia after being accused of having illegally appropriated 22,000 hectares of Colombian peasants' land in Antioquia department.

Two days ago, ELN, the second largest guerrilla group in Colombia, reaffirmed their willingness to start a peace process with the government, though it would not declare ceasefire, a condition imposed by the government.