Ecopetrol S.A. (BVC: ECOPETROL; NYSE: EC; TSX: ECP) announces that it has proven the presence of hydrocarbons at Cusuco 1, an exploratory well located within the municipality of San Carlos de Guaroa, Meta Province, Colombia.

Cusuco 1 is part of the CPO-10 Exploration and Production Agreement of December 18, 2008 between Ecopetrol and the National Hydrocarbons Agency. Ecopetrol holds 100% interest in this block.

Initial tests carried out on the Cusuco 1 well, using an artificial lift system, yielded an average crude oil production of 140 barrels of oil per day (BOD) of 13.8° API and a water cut of 4%. Ecopetrol will keep on running extensive testing in the coming weeks.

Ecopetrol is Colombia’s largest integrated oil & gas company, where it accounts for 60% of total production. It is one of the top 40 oil companies in the world and the fourth largest oil company in Latin America. The Company is also involved in exploration and production activities in Brazil, Peru and the United States Gulf Coast, and owns the main refineries in Colombia, most of the network of oil and multiple purpose pipelines in the country, petrochemical plants, and is entering into the biofuels business.