2009-08-15-2009-03-01

Will receive 25% interest in 2 offshore blocks, increasing total to 50% in each.

Ecopetrol SA, Bogota, Colombia, (NYSE: EC) plans to acquire additional interest in two Colombian blocks from the Colombian subsidiary of partner BHP Billiton Petroleum Corp., Melbourne, Australia, (NYSE: BHP). The assets include 25% interest in the Fuerte Norte and Fuerte Sur blocks, both in the Colombian Caribbean Sea. Both companies will then own 50% each in the blocks. The Fuerte Norte and Fuerte Sur blocks cover 954,050 hectares and correspond to the hydrocarbons exploration and exploitation contracts executed in April 2006 by BHP Billiton and Ecopetrol with the National Hydrocarbons Agency and the joint operation agreements executed by the parties in June 2007.