AMER.L Regulatory News (AMER)

4th February 2010

Amerisur Resources Plc ("Amerisur" or the "Company")

Colombia Operations Update

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to provide the following update on the Fenix contract in Colombia.

The rig Latco-02 has been contracted by the Company and is currently rigging up over the well Iguasa-1. It is expected to commence testing operations during the next few days. The programme is designed to test up to 9 discrete sandstone intervals in the lower section of the well and is expected to take approximately 28 days.

Subsequent to the testing of Iguasa-1, additional equipment will be installed at the rig site to allow the Latco-02 to drill and test the well Isabel-1, which is designed to explore the upper prospect encountered during the drilling of Iguasa-1. Isabel-1, which has been designed to optimally explore the potential of the upper sheet, is expected to take approximately 27 days to drill and test.

 John Wardle, CEO, said:

"Following the encouraging early signs during drilling and from the short test we performed, we are now in a position to fully test Iguasa-1. We look forward to updating shareholders as to progress."

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 24 years experience in the industry, having worked for BP, Britoil, Emerald Energy and Pebercan, and is a trained drilling engineer.

ENQUIRIES:

Notes to editors

The Fenix Contract is an Exploration and Production Contract held with the Agencia Nacional de Hidrocarburos. The block is located in the Middle Magdalena Valley area of Colombia and covers 24,116 hectares. Nearby oil fields include Bonanza, Provincia and Payoa. The Company holds 100% of the block through its subsidiary companies. Amerisur´s first exploration well on the block, Iguasa-1 was drilled during October and November 2009. The contract is currently in the second exploration phase of 14 months which terminates on 21 February 2010. The exploration commitment for that phase was satisfied by the drilling of Iguasa-1. The exploration commitment for the third phase, which begins on 22nd February 2010 and ends 21st April 2011 will be fully completed by the drilling of Isabel-1.