Platanillo-5 update

04 September 2012

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

Platanillo-5 Update

·; Platanillo-5 spudded, currently at 5,300ft

·; Platanillo-4 placed on controlled commercial production

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

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on the well Platanillo-5 in the Platanillo Field, Colombia, the third of a planned eight well drilling campaign.

Platanillo-5 is being drilled directionally to a reservoir target approximately 1,400ft north of the bottom hole location of Platanillo-3. The well has been spudded and is now at a depth of 5,300ft. The Company expects log data from this well and to update the market by the end of September.

Platanillo-3 continues to produce commercially at a controlled rate of approximately 1,500 BOPD. Platanillo-4 has been placed on commercial production with a permanent completion at an initial controlled rate of 500 BOPD. The Company expects to exit 2012 with a production rate of 5,000 BOPD.

Following completion and placing on production of Platanillo-5, the Serinco Rig D-10 will be moved to a new, fourth cellar (currently under construction) on Platform 9 to drill an additional well, named Platanillo-9 (due to the order in which wells were permitted with the Ministry of Mines and Energy) which will be directionally drilled to a location approximately 1,600ft west of Platanillo-3.

John Wardle, Chief Executive Officer, commented:

"Our new production is being carefully and efficiently brought on stream, in an increasing trend, in line with our reservoir management objectives, while drilling continues according to plan. I look forward to updating shareholders further as our work progresses."

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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