AMER.L Regulatory News (AMER)

13th July 2011

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

Operations Update

Amerisur Resources Plc, the oil and gas producer and explorer focused on South America, announces today an update on operations in Colombia and Paraguay.

Platanillo

The Company applied for a modification of the Platanillo Global Environmental License to the Ministry of Environment, Housing and Territorial Development (MAVDT) on 21st January 2011. That modification contemplated the construction of an access road to the southern part of the field and 8 new drilling locations within that section. The Company has maintained a close contact with MAVDT and has promptly provided all the information and assistance required by the environmental authorities. The proposal is under review by MAVDT.

It is expected that the drilling programme will be underway during Q4 2011. Given the delays occasioned by the permitting process the Company expects to complete 3 new wells during 2011, however the drilling programme would continue consecutively should results merit, thus completing the total of 6 new wells during H1 2012.

San Pedro Block Paraguay

The 13,000 km Aeromagnetometry programme was completed on time and on budget and Fugro is well advanced with the data processing. The Company expects to begin interpretation during July 2011.

John Wardle, CEO, said:

"The tremendous growth of activity in the Petroleum and Mining sectors in Colombia has placed an unprecedented load upon regulatory resources. This is an extraordinary situation, never seen before in the Colombian industry and has had an extraordinary effect upon the operations of all Operators in the country. Our respect for the environment where we work is paramount and is an integral part of our business. I believe we have maintained these high standards in our work and proposals to date. All preparations for the drilling programme are complete, and have been so for some time, hence once we receive the approval of the environmental modification I expect to achieve rapid progress."

Competent person: Technical information in this announcement has been reviewed by John Wardle Ph.D., the Company's Chief Executive. John Wardle has 25 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 Platanillo contract is a commercial area held with the Agencia Nacional de Hidrocarburos located in the Putumayo basin of southern Colombia, near the border with Ecuador. The Company has a 100% interest in this area. As a commercial area, the Platanillo block has no exploration commitments. The exploitation period is 24 years, with the facility to extend to the end of field economic life should the Company wish to do so. The Exploitation Area was extended during 2010 up to the national boundary to the south of the previous block limit.