BOGOTA, June 26 (Reuters) - Production of cocaine in Colombia was down 6 percent in 2013, the lowest figure on record, though planting of coca, the raw material used to make the narcotic, remained stable, the United Nations said in a report on Thursday.
Cocaine output in the Andean country, one of the top global producers of the drug, was down to 290 tonnes from 309 tonnes in 2012, due to a fall in coca productivity and fertilizer use.
The figure is the lowest since estimates began. Production was at its height in 2005, when it reached 680 tonnes.
Coca plantations covered 48,000 hectares in 2013, the same area as in 2012, according to the report by the United Nations Office on Drugs and Crime and Colombia's justice ministry.
Colombia has battled drug-funded rebel and paramilitary groups for five decades in a conflict that has killed over 200,000 and displaced millions.
The government began peace talks with the Revolutionary Armed Forces of Colombia, or FARC, 1-1/2 years ago, reaching partial agreements on three of the five discussion topics, including an accord on the Marxist rebels' exit from the illegal drug trade.
The FARC publicly admitted its involvement in the narcotics trade for the first time. Any final peace accord must first be approved by referendum and then Congress.
For its part, the government will cut back on U.S.-funded aerial fumigation programs, which opponents argue damage the environment and the health of rural residents.
The accord allows fumigation under certain conditions, including when coca plantations are far from populated areas or when communities refuse manual eradication.
Cocaine is produced in a lengthy process in which coca leaves are combined with gasoline, sulfuric acid and other chemicals before being refined into a powder.
Six of Colombia's 32 departments were home to 82 percent of the coca plantations, according to the report. Three, Narino, Norte de Santander and Putumayo, were responsible for more than half the crop.
Prices for coca leaves fell 22 percent last year, possibly because of price speculation and the involvement of armed agents or new producers, the report said. (Reporting by Luis Jaime Acosta and Julia Symmes Cobb; Editing by Peter Galloway)