SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 OF THE

SECURITIES EXCHANGE ACT OF 1934

May 2012

Commission File Number: 333-153452

ECOPETROL S.A.

(Exact name of registrant as specified in its Charter)

Carrera 7 No. 37 – 69

BOGOTA – COLOMBIA

(Address of registrant’s principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F x Form 40-F o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Yes        o No x

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Yes        o No x

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes        o No x

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):  82-    N/A  

Financing assured for phase 1 of Bicentenario Pipeline

Ecopetrol (NYSE: EC; BVC: ECOPETROL; TSX: ECP) announces the financial closing of the phase 1 of the Bicentenario Pipeline. The financing was completed with a syndicated loan from Colombian banks in the amount of $2.1 trillion pesos. The financial terms include an interest rate of DTF + 4.54%, and a term of 12 years with a 1-year grace period.

The loan does not include any financial guarantee from the partners. However, there are “ship or pay” transport commitments from the partners which are intended to ensure the necessary revenues to meet the debt service payments of the syndicate loan.

Seven oil companies with operations in Colombia are partners in the Bicentenario Pipeline (including Ecopetrol with a 55% stake). The pipeline will transport oil from the Llanos Orientales region to the port of Coveñas on the Colombian Caribbean coast. Phase 1 of the pipeline will connect the stations of Araguaney and Banadía.

Bogota, Colombia – May 11, 2012

Ecopetrol is Colombia’s largest integrated oil & gas company, where it accounts for 60% of total production. It is one of the top 50 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.

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 Téllez

Phone: + 571-2345377

Fax: +571-2344480

Email: mtellez@ecopetrol.com.co

Website: www.ecopetrol.com.co

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereto duly authorized.

Date: May 10, 2012

Ecopetrol S.A.
By:	/s/ Adriana M. Echeverri
Name:	Adriana M. Echeverri
Title:	Chief Financial Officer