Platanillo-4 Update

24 August 2012

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

Platanillo-4 Update

·; Platanillo-4 flowed 30.3°API oil with trace water at 1,100 BOPD in natural flow over a restricted choke

·; Platanillo-4 to be placed on commercial production early next week

·; Platanillo-3 continues to produce commercially at a controlled rate of approximately 1,500 BOPD

·; Platanillo-5, the third well in the planned eight well programme to spud early next week

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on the well Platanillo-4 in the Platanillo Field, Colombia, the second of a planned eight well drilling campaign.

A 29ft section of the logged 75ft gross oil column was perforated in the U formation in order to perform flow tests. Over a flow period of 48 hours the interval produced in natural flow at an increasing rate. The test was terminated at a production rate of approximately 1,100 barrels per day of 30.3° API oil with trace water, while choked back and with wellhead pressure of approximately 50 psi. The production curve showed an increasing trend, indicating that the stabilised commercial production rate may be higher. The Drill Stem Testing assembly has now been removed from the well and the permanent production system is being installed to place the well on commercial production.

Platanillo-3 continues to produce commercially at a controlled rate of approximately 1,500 BOPD and the Company remains confident of achieving a year end production rate of 5,000 BOPD.

Following completion and placing on production of Platanillo-4 the Serinco Rig D-10 will be skidded to the third drilling cellar, to drill the third well (Platanillo-5) of our current programme from the same location (Platform 9), deviating the well to an offset of approximately 1,400ft north from the bottom hole location of Platanillo-3. Platanillo-5 is expected to spud early next week, with log data available in approximately one month. As previously reported, given the positive results of the wells, the Company intends to drill a total of 4 wells from Platform 9 instead of the 3 wells planned previously. The additional well, named Platanillo-9 (due to the order in which wells were permitted with the Ministry of Mines and Energy) will be directionally drilled to a location approximately 1,600ft west of Platanillo-3.

John Wardle, Chief Executive Officer commented:

"I am very pleased with the results of Platanillo-4, which contributes substantially to the new production capacity we are adding with each well. The well response is excellent, and we plan to improve the productivity still further once on commercial production."

ENDS

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 28 years' experience in the industry, having worked for BP, Britoil, Emerald Energy and Pebercan, and is a trained drilling engineer.

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