Operations Update

28 June 2012

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

Operations Update

 Highlights:

·; Previous 6 well campaign increased to 8 new wells for the south and intermediate northern prospects and a further 4 wells planned for the northern prospects

·; Platanillo-3 placed on commercial production at a controlled rate of 1,500 BOPD in natural flow

·; Platanillo-4 well spudded on 24 June

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, is pleased to announce an update on operations in the Platanillo Field, Colombia.

After analysis of the production test from Platanillo-3, the Company has re-designed the off take programme in the southern part of the field to take into account the exceptional production characteristics of the U sand reservoir encountered. In place of the previous 6 well programme covering the south and intermediate northern prospects, 8 new wells will be initially dedicated to the southern lobe around Platanillo-3 over the coming months with a further 4 wells planned for the northern prospects. This programme is designed to facilitate an optimised drainage of this highly productive area, and ensure a prudent management of this excellent reservoir and will be funded out of operating cash flow and existing cash resources.

Platanillo-3 has been placed on commercial production from the previously reported U sand interval, at a controlled rate of approximately 1,500 BOPD.

The Platanillo-4 well was spudded on 24 June and is currently drilling ahead at approximately 2,000ft.

Giles Clarke, Chairman of Amerisur, said: "Excellent and rapid progress from our Colombian team, placing our new well on production within hours of the drilling rig being moved on to the next well, which is advancing according to programme. I look forward to further impressive results from our Colombian assets."

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.

An updated presentation is available on the Company website www.amerisurresources.com.

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