AMER.L Regulatory News (AMER)

10 April 2012

AMERISUR RESOURCES PLC ("Amerisur", "the Company" or "the Group")

Audited Results for the year ended 31 December 2011

Amerisur Resources PLC, the oil and gas producer and explorer focused on South America, announces results for the year ended 31 December 2011.

Highlights:

·; Operating profit up 47% to US$3.3m (9 months to Dec 2010: US$2.2m )

·; Cash position at year end US$17.3m, all 2012 commitments fully funded

·; Colombia: Significant progress in Platanillo Block and new prospects in Fenix

·; Paraguay: Aerial magnetic survey completed

·; Post period end:

Ø Planned Six well Platanillo drilling campaign commenced in March 2012

Ø Remain focused on targeting 5,000 BOPD from Platanillo Field by end of 2012

Ø 2P reserves increased 114% to 7.7 MMBO, 3P reserves at 10.6 MMBO

Ø New prospecting permits for over five million hectares awarded in Paraguay

Giles Clarke, Chairman of Amerisur Resources said:

I am pleased to report that we delivered strong progress last year in spite of difficult operating conditions and are now focused on our exciting drilling programme at Platanillo. The reserves upgrade on the basis of the new 3D seismic model is very encouraging and we plan to increase those reserves further with our programme this year. We have also developed significant new opportunities in Paraguay and we look forward to our exploration programme there.

This will be an exciting year for the Company in which, as always, we are seeking to drive shareholder value through our target of delivering 5,000 BOPD by the end of the year. We wholly own all our assets, have excellent operating abilities, a strong cash balance and with all our commitments fully funded look to the future with great confidence.

We would like to thank all of our shareholders, host Governments, local communities and employees for their continued support during this exciting phase for the Company.

For further information please contact:

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.

Chief Executive's Statement

Colombia

Platanillo

Despite a challenging operating environment we delivered strong progress this year which has allowed us to continue the development of our commercial Platanillo field with the objective of significantly increasing production.

The early part of the year saw the initial results from our 125 km2 3D/3C seismic acquisition programme over our 11,047 hectare commercial area. This work was performed with "state of the art" digital multicomponent geophones, the first time this system has been applied in the Colombian Caguan-Putumayo basin. The information generated was of significantly higher quality than the previous 2D seismic data in terms of density, resolution and frequency content and the images generated, while explaining some anomalous drilling results, highlighted a large potential upside in the field. During the year we continued to process and reinterpret the 3D data, using various specialist contractors as well as in-house resources. These efforts have led to important increases in vertical resolution and facies discrimination. We continue to identify new features of the field, and our understanding of the oil model in this area is improving continually, which further supports the Monte Carlo model of prospective resources reported previously and which I believe will bring significant benefits to the Company.

An important prospective upside lay to the south, between our existing wells and the northern Victor Hugo Ruales wells, within the recently extended part of the contract area, which had been approved for incorporation into the contract by the Agencia Nacional de Hidrocarburos (ANH) on 10 December 2010. This new area was not covered by the original environmental licence issued on 17 December 2009 to cover the exploitation phase, and hence an application was prepared to modify that licence. Although the statutory processing period for such a modification is 55 working days, 305 days were required before the modification was granted on 22 November 2011. This modification expanded the permitted area for drilling and production activities from 935 to 4,480 hectares, covering the majority of the Platanillo structure, and contemplated up to 55 new wells from 16 drilling platforms, together with the civil engineering works required to gain access and provide safe working areas. The application was closely studied by the Ministry of Environment, Housing, Development and Territory (MAVDT, now Ministry of Environment and Sustainable Development, MADS), and the Company was required to provide both additional data and alternative routes for the main access roads.

The civil works, including approximately 7km of new roads to the south, 3km of new roads to the north, raised drilling locations and the construction of a 15 metre, 80 tonne capacity bridge, were initiated immediately and the southern works were completed at the end of February 2012. The programme envisages the drilling of three wells initially from the southern location, Platform 9. Within the same programme we then plan to drill a further three wells at locations to be confirmed once results from the initial set are in hand.

In March 2012, post period end, the Company signed the Serinco D10 1200HP drilling rig for the programme, on a contractual basis of two firm wells, with a continuing option to extend for further wells. Serinco SA is an established Drilling and Work Over rig provider and contractor which has performed various operations previously for the Company. At the time of writing the rig is being mobilised to Platform 9 and we expect to have results from Platanillo-3 in May 2012. The drilling campaign is targeting an increase to 35MMBO 2P reserves in the field and we remain confident of reaching the 5,000 BOPD target this year from Platanillo.

In addition, in February 2012 the Company worked over the Platanillo-2 well in order to test the N sand with the objective of calibrating the petrophysical model. That zone flowed oil of 17.9° API to surface in natural flow and is currently being tested with an Electrical Submersible Pump. At the time of writing the Company is configuring the surface reception and treatment systems in order to efficiently handle and condition the flow for a Long Term Test of the N sand. The information developed by this work over will be essential in the interpretation of the new wells. The positive test in the N sand now brings us up to 4 tested oil reservoirs, the T sand, B limestone/calcareous sandstone, the Lower U sand and the N sand, with the M1, M2 and Caballos formations as potential reservoirs in the new wells.

Most recently, on 28 March 2012, the Company announced results from the updated independent reserves report for the Platanillo field as at 31 December 2011 undertaken by Petrotech Engineering Ltd using the standards set by the Oil and Gas Reserves Committee of the Society of Petroleum Engineers, and in compliance with Canadian Form 51-101 F2. Certified 2P reserves have increased by 114% to 7.7 MMBO. 3P reserves have also been calculated at 10.6 MMBO. The uplift in reserves is based solely upon the improved mapping afforded by the 3D/3C seismic data. The 2P reserves were calculated by Petrotech to represent a Net Present Value ("NPV") of US$401m undiscounted and a 10% discounted NPV of $204m.

Fenix

At Fenix the shallow discovery tested by the Isabel-1 well has entered commerciality post the evaluation period and is currently closed in while the Company applies for a global exploitation licence. Iguasa-1, which is located within the same area, is also closed in currently. The Company continues to evaluate the data from these wells in an effort to understand the reasons for the abnormally low productivity seen in the lower well sections, and so design a remedial treatment to obtain higher flow rates from the oil saturated sands. The decline of the production rate in Isabel-1 is well understood, and the Company considers this discovery to be viable so long as the well trajectories are designed to capture further oil bearing sands in the Mugrosa/Esmeraldas sequence.

During the year we completed the design of a 2D seismic programme to be performed in the southern part of the block, where more traditional geology prevails, and where we have developed a new prospect and two leads, which we calculate to together represent a potential resource range of 52 to 74 MMBO. The prospect, known as "Shallow K" is based upon a recently mapped and confirmed surface anticline in the Upper Cretaceous formation. The leads, which require further 2D seismic as mentioned above, are named Bonanza South and Bonanza East. We expect to acquire the new 2D seismic data before the end of June 2012.

The Commercial Agreement with Reto Petroleum, under which Reto has the right to acquire a working interest in the Fenix Exploration and Production contract in exchange for the funding of an agreed work programme, lapsed (as regards exclusivity) due to Reto's delay in raising funding for the programme. Other interested parties have reviewed and in two cases continue to review the data. The Company has received expressions of interest and outline offers but is not able to confirm when or if any farm out will occur.

Paraguay

Between April and July 2011 we acquired a 39,000 line km aerial magnetic survey, designed to map the general development of sedimentary series and basement in the basin and provide detailed data within the San Pedro block. This data was complemented with existing gravity data from commercial sources and integrated into a basin study. The study indicated that the Parana basin is significantly more complex from a geological point of view than previously thought. The simplistic model of a general deepening towards the basin maximum deep point near the border with Brazil was shown to be in a general sense true, but also that important character exists within the basin, and local sedimentary deeps exist. Some of those deeps mapped near to and within the San Pedro block may contain sedimentary thicknesses of up to 21,000 ft. Given the lithological understanding derived from wells drilled in the area, the potential source rocks; through that depth range are likely to be within the generative windows for both oil and gas. This finding is very encouraging and also gives a more feasible explanation for the source of the anomalously high surface geochemical manifestations previously reported - since it was difficult to model such anomalies migrating without significant attenuation over hundreds of kilometres from the previously presumed kitchen zone. The possible presence of local kitchens more logically supports the values recorded in the field.

Having seen these surprising results the Company immediately sourced gravity data over other basins within Paraguay. The Piriti and Pilar basins in the western part of the country, which conjoin the oil producing Lomas de Olmedo basin in Argentina, were studied. The basement map created from these data indicated that the basins were in fact connected and displayed great sedimentary thickness coupled with a system of highs and lows whose genesis is as yet unconfirmed. On the basis of the definition of the Piriti-Pilar complex, in December 2011 we made three new applications for Prospection Permits within the areas indicated to be prospective by the study. These contracts, which are designed to allow initial prospection works to proceed while protecting the Company's rights over the areas, have been approved by the Evaluation Committee of the Paraguayan Ministry of Public Works, and the Company expects to begin initial studies during Q2 2012. The three areas are named Espartillar, Coronillo and Las Palmas, and cover 2,400,000, 2,400,000 and 401,059 hectares respectively.

The last year has seen a strong uptick in interest in Paraguay from international oil companies, and the Company has secured a strategic acreage position over areas where it has privileged data and concepts. We intend to acquire further detailed gravity data in the new blocks to complement the model, prior to the decision on whether to farm out interests in these assets for the acquisition of seismic data and drilling of the prospects thus developed.

New opportunities

The Company continued to evaluate new growth opportunities throughout the year. In 2012 the ANH is planning to launch a licensing round, and we are currently studying the areas on offer.

Financial Review

Revenue for the period increased to US$14.2m (9 months to Dec 2010: US$9.0m). Profit before all taxes was US$3.5m (9 months to Dec 2010: US$2.3m) and operating profit was US$3.3m (9 months to Dec 2010: US$2.2m). At the period end, the Group had cash of US$17.2m (2010: US$20.7m). All current commitments are fully funded.

Board Change

George Woodcock was appointed as a non-executive Director in November 2011. George is an oil industry veteran with significant knowledge and experience in managing oil and gas assets in Colombia. I welcome him to the board and look forward to working with him.

Outlook

Our principal focus during the first part of this year will be to deliver the drilling programme in Platanillo, where we are hopeful of success based on our analyses to date. Fenix continues to develop, and the potential in the south of the block will allow us to usefully develop the area in the coming phases, without depending on production enhancement success in the north. Paraguay is becoming more and more interesting and valuable; I am very happy to report that we have secured such a strong acreage position, with excellent contractual terms, while holding data which gives us a unique insight. I believe our outlook is very positive and I look forward to the future with confidence for our Company.

John Wardle

Chief Executive Officer

5 April 2012

The financial statements were approved by the Board of Directors on 5 April 2012.

N. Harrison

Director

Company number: 4030166

Consolidated statement of changes in equity

Notes to the preliminary announcement

 1 Basis of preparation

 The summary accounts do not constitute statutory accounts as defined in section 435 of the Companies Act 2006, but has been extracted from the statutory accounts for the period ended 31 December 2011on which an unqualified audit report has been issued. The statutory financial statements for the period ended 31 December 2011 were approved by the directors on 5 April 2012, but have not yet been delivered to the Registrar of Companies.

The financial statements have been prepared in accordance with applicable International Financial Reporting Standards (IFRS) and International Financial Reporting Interpretation Committee (IFRIC) interpretations as adopted by the EU. The Group financial statements consolidate those of the company and of its subsidiary companies drawn up to 31 December 2011.

Intra-group transactions are eliminated on consolidation and all figures relate to external transactions only. Acquisitions of subsidiaries are dealt with by the acquisition method of accounting except for those qualifying as group reconstructions where merger accounting is used. The results of newly acquired companies are consolidated from the date that control passed.

 2 Posting of accounts

The Report and Accounts for the period ended 31 December 2011 will shortly be available on the Company's website and will be sent to registered shareholders who have elected to receive paper communications by post in due course.