BOGOTA, May 8 (Reuters) - Colombia's cultivation of coca leaf used to manufacture cocaine decreased 9 percent last year, a preliminary United Nations study has found, according to a security source familiar with the figures. The United Nations Office for Drugs and Crime, which conducts a yearly satellite study with Colombian officials, last year reported 86,000 hectares (212,500 acres) of coca leaf cultivation in Colombia for 2005. "The preliminary measure with the satellite system by the United Nations established a reduction of 9 percent in the area cultivated up to Dec. 31, 2006," said the source, who asked not to be identified because official figures are programmed to be released in June. A spokesman for the U.N drugs office in Colombia would not comment on the figures. Colombia remains the world's top producer of cocaine despite more than $4 billion in U.S. funding for coca leaf eradication and military and counter-narcotics aid to fight leftist rebels and drug traffickers. President Alvaro Uribe credits U.S. aid with helping slash violence in Colombia and reducing coca leaf in areas once awash with the crop, which has helped stoke the fighting between guerrillas and illegal right-wing paramilitaries. But some U.S. Democrats in Congress are questioning the success of so-called Plan Colombia and are reviewing whether future aid to the Andean country should focus less on military financing and more on alternative programs to ween coca farmers off the lucrative crop. Uribe is also under fire at home and from rights groups over a scandal linking some of his lawmaker allies to paramilitary warlords who have now disarmed, but who are accused of some of the worst atrocities in the conflict. U.S. Drug Enforcement Administration director Karen Tandy said in Spain on Tuesday that aid to Colombia had not driven up the price of cocaine on U.S. streets. Higher prices would be one indication that less of the drug was coming into the market.
