Rockhopper Regulatory News (RKH)

For immediate release: 11 September 2012

Rockhopper Exploration plc

("Rockhopper" or the "Company")

Result of Annual General Meeting

Rockhopper Exploration plc (AIM: RKH), the North Falkland Basin oil and gas exploration company, is pleased to announce that all resolutions proposed at the Annual General Meeting ("AGM") of the Company held today were duly passed.

A presentation given at the AGM is available for viewing on the Company's website:

http://www.rockhopperexploration.co.uk/rockhopper/investors/presentations.html

Enquiries:

Notes to Editors:

Rockhopper was established in February 2004 with a strategy to invest in and carry out an offshore oil exploration programme to the north of the Falkland Islands. The Company floated on AIM in August 2005 and holds a 100 per cent. interest in four offshore production licences: PL023, PL024, PL032 and PL033 which cover approximately 3,800 sq. km. Rockhopper has further interests in licences PL003, PL004a (7.5 per cent. interest in both) and PL004c (25 per cent. interest), which are operated by Desire Petroleum plc. Additionally, the Company has a significant interest in licence PL004b which contains the extension to the Sea Lion Field as well as the Beverley, Casper and Casper South discoveries, where it holds operatorship and an aggregate 60 per cent. interest.

An extensive work programme has been carried out over a number of years on the licences operated by Rockhopper. This has included 2D and 3D seismic and controlled source electromagnetic mapping. In February 2010, the Ocean Guardian drilling rig arrived in Falkland waters to carry out a multi-well drilling campaign. Rockhopper drilled an exploration well on Sea Lion during April and May 2010, the result of which was the first oil discovery and Contingent Resource in the North Falkland Basin. The Sea Lion discovery was successfully tested during September 2010 and June 2011 and was the first oil to flow to surface in Falkland Islands waters. Rockhopper's drilling campaign lasted from 16 April 2010 to 8 January 2012 and resulted in seven successful wells of the ten drilled, with three oil discoveries, three gas discoveries, multiple successful Sea Lion appraisal wells and a successful appraisal well on Casper.

In July 2012 Rockhopper announced that it had entered into a conditional farm-out agreement with Premier Oil plc, whereby Premier agreed to acquire 60 per cent. of Rockhopper's interests in its North Falkland Basin licences. Customary closing conditions are hoping to be satisfied within the coming few weeks.

Rockhopper Exploration plc www.rockhopperexploration.co.uk