Rockhopper Exploration plc
(“Rockhopper” or the “Company”)

Results of Open Offer and Total Voting Rights

Rockhopper Exploration plc (AIM: RKH), the oil and gas company with key interests in the North Falkland Basin, announces the results of its Open Offer to Qualifying Shareholders, itself announced on 27 August 2026 and which, in accordance with its terms, closed for acceptances at 11.00 a.m. on 15 September 2026.

The Company is pleased to announce that valid acceptances were received from Qualifying Shareholders for a total of 24,242,324 Open Offer Shares under the Open Offer, representing a take-up of approximately 118% per cent. of the 20,529,259 Open Offer Shares available under the Open Offer.

Qualifying Shareholders who have validly applied for Open Offer Shares will receive their full basic entitlement. Applications for New Ordinary Shares under the Excess Application Facility have been scaled back on a pro rata basis, in accordance with the terms of the Open Offer as outlined in the Circular.

Accordingly, the Open Offer has raised total gross proceeds of approximately US$20 million (approximately £14.4 million) through the issue of a total of 20,529,259 Open Offer Shares.

Admission and dealings

The Open Offer Shares will, when issued, be credited as fully paid and will rank pari passu in all respects with each other and with the Existing Ordinary Shares, including the right to receive all dividends and other distributions declared, made or paid after the date of Admission. Application has been made to the London Stock Exchange for the Open Offer Shares to be admitted to trading on AIM (“Admission”). Dealings in the Open Offer Shares and Admission are expected to take place on or around 8.00 a.m. on 18 September 2026.

Total voting rights

The Company confirms that, upon Admission of the Open Offer Shares, which is expected to occur on 18 September 2026, the issued ordinary share capital of the Company will consist of 1,071,968,721 Ordinary Shares of 1 pence each with voting rights attached and there will be no Ordinary Shares held in treasury. This issued share capital figure can be used by Shareholders as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change to their interest in, the Company under the FCA’s Disclosure Guidance and Transparency Rules.

Sam Moody, Chief Executive Officer of Rockhopper Exploration, commented:

“We’re delighted with the results of the Open Offer and very grateful for the continuing support of our shareholders. We look forward to updating them as we continue to make progress at Sea Lion.”

Capitalised terms in this announcement have the meaning ascribed to them in the Company’s circular published on 28 August 2026.

Enquiries:

Rockhopper Exploration plc
Sam Moody – Chief Executive Officer
Tel. +44 (0)20 7390 0230 (via Vigo Consulting)

Canaccord Genuity Limited (NOMAD and Joint Broker)
Henry Fitzgerald-O’Connor/James Asensio/Charlie Hammond
Tel. +44 (0) 20 7523 8000

Peel Hunt LLP (Joint Broker)
Richard Crichton/Georgia Langoulant
Tel. +44 (0) 20 7418 8900

Vigo Consulting
Patrick d’Ancona/Ben Simons/Fiona Hetherington
Tel. +44 (0) 20 7390 0234

Notes to Editors
Rockhopper Exploration plc is a UK-based oil and gas exploration and production company with key interests in the Falkland Islands. The Company holds a 35% interest in licences in the North Falkland Basin, where it has sanctioned the development of the significant Sea Lion field which was originally discovered by the Company in 2010.
Rockhopper’s shares are quoted on the AIM market of the London Stock Exchange under the ticker RKH.
www.rockhopperexploration.co.uk.