Response to Statement by Prima Energy

2 September 2026 - Singapore: Jadestone Energy plc (AIM:JSE) (the "Company" and together with its subsidiaries, "Jadestone" or the "Group"), an independent upstream production and development company focused on the Asia-Pacific region, notes the announcement by PT Prima Petroleum Energi (“Prima Energy”) that Prima Energy has reached an agreement to acquire an interest in c.28.3% of the Company's issued share capital from Tyrus Capital S.A.M. (the “Sale”).

Jadestone has not yet received independent confirmation of the Sale.

Jadestone also notes Prima Energy’s statement that it has no intention of making an offer to acquire Jadestone Energy plc and is bound by the terms of Rule 2.8 of the UK Takeover Code in that respect.

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About Jadestone Energy

Jadestone Energy plc is an independent upstream company focused on the Asia-Pacific region. It has a balanced and increasingly diversified portfolio of production and development assets in Australia, Malaysia, Indonesia and Vietnam, all stable jurisdictions with a positive upstream investment climate.

The Company is pursuing a strategy to grow and diversify the Company’s production base both organically, through developments such as Nam Du/U Minh in Vietnam and the Puteri Cluster offshore Malaysia, as well as through acquisitions that fit within Jadestone’s financial framework and play to the Company’s strengths in regional upstream development and operations and managing maturing oil assets. Jadestone delivers value in its acquisition strategy by enhancing returns through operating efficiencies, cost reductions and increased production through further investment.

Jadestone is a responsible operator and well positioned for the energy transition through its increasing gas production, by maximising recovery from existing brownfield developments and through its Net Zero pledge on Scope 1 & 2 GHG emissions from operated assets by 2040. This strategy is aligned with the IEA Net Zero by 2050 scenario, which stresses the necessity of continued investment in existing upstream assets to avoid an energy crisis and meet demand for oil and gas through the energy transition.

Jadestone Energy plc (LEI: 21380076GWJ8XDYKVQ37) is listed on the AIM market of the London Stock Exchange (AIM: JSE).  The Company is headquartered in Singapore.  For further information on the Company please visit www.jadestone-energy.com.

The information contained within this announcement is considered to be inside information prior to its release, as defined in Article 7 of the Market Abuse Regulation No. 596/2014 which is part of UK law by virtue of the European Union (Withdrawal) Act 2018.