Ecopetrol Takes Over Operations of the Cupiagua Fields Beginning July 2010

BOGOTA, Colombia, Nov. 12 /PRNewswire-FirstCall/ — On November 12, 2009
Ecopetrol S.A. (NYSE: EC) (“Ecopetrol” or the “Company”) 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%).

(Logo: http://www.newscom.com/cgi-bin/prnh/20090209/ARM001LOGO )

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.

Ecopetrol is Colombia’s largest integrated oil company and is among the
top 40 oil companies in the world and the four largest oil companies in Latin
America. Besides Colombia, where it accounts for 60% of total production, the
Company is involved in exploration and production activities in Brazil, Peru
and the United States (Gulf of Mexico). Ecopetrol has the principal refinery
in Colombia, most of the network of oil and multiple purpose pipelines in the
country, and it is considerably increasing its participation in biofuels.

This release contains forward-looking statements relating to the prospects
of the business, estimates for operating and financial results, and those
related to growth prospects of Ecopetrol. These are merely projections and, as
such, are based exclusively on the expectations of management concerning the
future of the business and its continued access to capital to fund the
Company’s business plan. Such forward-looking statements depend,
substantially, on changes in market conditions, government regulations,
competitive pressures, the performance of the Colombian economy and the
industry, among other factors; therefore, they are subject to change without
prior notice.

    Contact us for any additional information:

    Investor Relations
    Alejandro Giraldo
    Phone: +571-234-5190
    Email: investors@ecopetrol.com.co

    Media Relations (Colombia)
    Mauricio Tellez
    Phone: + 571-2345377
    Fax: +571-2344480
    Email: mtellez@ecopetrol.com.co

    Website: www.ecopetrol.com.co

SOURCE Ecopetrol S.A.