DES.L Regulatory News (DES)

For immediate release: 14 March 2011

Rockhopper Exploration plc

("Rockhopper" or the "Company")

Additional Drilling Slots

&

Seismic Programme Update

Rockhopper Exploration plc (AIM: RKH), the North Falkland Basin oil and gas exploration company, announces that it has entered into an assignment agreement to secure three firm additional well slots on the Ocean Guardian drilling rig. Rockhopper intends to utilise these three well slots after Desire Petroleum plc completes drilling operations on its next well, which follows the appraisal well currently being drilled by Rockhopper.

Rockhopper further announces that the acquisition of new 3D seismic data to the south of the Sea Lion discovery well, on licence PL032, has been completed and the Company intends to fast track the processing of this data. It is anticipated that the resulting processed data will become available to the Company during July 2011. The wider seismic acquisition programme, over areas of licences PL024, PL032 and PL033 and adjacent areas, is ongoing.

Sam Moody, Chief Executive of Rockhopper, commented,

"The additional rig slots will see Rockhopper continuing an exciting and considerable work programme in the North Falkland Basin this year. Our understanding of the basin has advanced following the Sea Lion discovery, and will be further enhanced by our current appraisal operations, together with new seismic data. This information will be valuable in identifying our forward drilling programme."

Enquiries:

Rockhopper Exploration plc

Sam Moody - Chief Executive

Tel. +44 (0)20 7920 2340 (via M: Communications)

M: Communications

Patrick d'Ancona or Ben Simons

Tel. +44 (0)20 7920 2340

Canaccord Genuity Limited

Charles Berkeley / Henry Fitzgerald-O'Connor

Tel. +44 (0) 20 7050 6500

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 also farmed in (7.5% working interest) to licences PL003 and PL004, which are operated by Desire Petroleum. These licences have been granted by the Falkland Islands government.

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 (CSEM). 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 its Sea Lion prospect during April and May 2010, the result of which was the first oil discovery and Contingent Oil Resource in the North Falkland Basin. The Sea Lion discovery was successfully tested during September 2010 and was the first oil to flow to surface in Falkland Islands waters. Rockhopper has contracted seismic vessels MV Polarcus Asima and Nadia to carry out a 3D seismic survey, beginning December 2010, over areas of licences PL024, PL032 and PL033 which were not previously defined by 3D, as well as adjacent areas.

Rockhopper is currently carrying out further drilling on Licence PL032.

Rockhopper Exploration plc www.rockhopperexploration.co.uk