Ecopetrol to Take Reins at Cupiagua Fields in July 2010

On November 12, 2009 Ecopetrol S.A. announced in the municipality of Aguazul, department of Casanare, Colombia, that as of July 1, 2010 it will take over operation of the Cupiagua and Cupiagua Sur fields, following the expiration of the Santiago de las Atalayas Association Contract, whose partners are Ecopetrol (50%), BP Exploration Company-Colombia Ltd. and BP Santiago Oil Company (31%), and Tepma (19%).

In September 2009, the Cupiagua field produced an average of 17,087 barrels of oil per day (bpd) and the Cupiagua Sur field produced 12,208 bpd. Today, Ecopetrol's share is 50% of production after royalties; as of July, 2010, Ecopetrol's share will increase to 100% after royalties.

The Cusiana field operates under a structure shared by the Santiago de las Atalayas, Tauramena and Rio Chitamena Association Contracts under which the field would continue to be operated by BP Exploration, subject to the relevant contractual adjustments.

The Santiago de las Atalayas Association Contract was entered into in 1982 and will expire on June 30, 2010. This is the first association contract that expires in the Llanos Foothills. The other association contracts expire between the years 2016 and 2020, and include, among others, Cusiana, Cupiagua in Recetor, Volcanera, Pauto and Florena fields.