Platanillo-3 Update

30 May 2012

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

Platanillo-3 Update

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on the well Platanillo-3 in the Platanillo Field, Colombia, the first of a planned six well drilling campaign.

The well has successfully reached total depth at 8,250ft and has been logged, cased and cemented.

Drill Stem Testing equipment has been mobilised and is being rigged up to perform production tests. The surface equipment on location has also been constructed and commissioned.

The reservoir sections encountered in the well are currently being studied to determine which zones will be tested. Encouragingly, the Lower "U" formation was encountered 33ft higher than the next highest well in the field, in line with the 3D seismic model, indicating the potential for an increased oil column.

The Company expects to perform flow tests within the next week, and will announce results once they have been analysed.

Given the promising indications from Platanillo-3 the Company plans to skid the Serinco Rig D-10 and drill the second well of the current programme from the same location (Platform 9), deviating the well to an offset of approximately 700m from Platanillo-3.

ENDS

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 27 years' experience in the industry, having worked for BP, Britoil, Emerald Energy and Pebercan, and is a trained drilling engineer.

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