Mr. Robert Bose reports

SINTANA ENERGY INC. ANNOUNCES PUBLICATION OF SCHEME DOCUMENT IN CONNECTION WITH ACQUISITION OF CHALLENGER ENERGY GROUP PLC

Sintana Energy Inc. has provided an update with respect to its previously announced agreement with Challenger Energy Group PLC, pursuant to which Sintana will acquire all of the issued and to be issued ordinary share capital of Challenger. It is intended that the acquisition will be implemented by way of a court-sanctioned scheme of arrangement under Part IV (Section 152) of the Isle of Man Companies Act 1931 as amended from time to time.

Terms used but not otherwise defined in this announcement shall have the meanings given to them in the scheme document (defined below). All references to times in this announcement are to London, United Kingdom, times unless stated otherwise.

Publication of the scheme document

The independent Challenger directors and Sintana are pleased to announce that a circular in relation to the scheme has now been published. The scheme document sets out, amongst other things, a letter from the chairman of Challenger, an explanatory statement, the full terms and conditions of the scheme, a description of the new Sintana shares, an expected timetable of principal events, notices of the court meeting and general meeting, and details of the actions to be taken by Challenger shareholders. The scheme document has been published today and is available on Sintana's and Challenger's websites (subject to any restrictions relating to persons resident in a restricted jurisdiction).

Hard copies of the scheme document and forms of proxy for use at the court meeting and general meeting are being sent today to Challenger shareholders.

Action required and notices of the court meeting and the general meeting

As further set out in the scheme document, before the court's sanction can be sought for the scheme, the scheme requires, amongst other things, the requisite majorities of:

• Scheme shareholders voting in favour of the resolution to be proposed at the court meeting;
• Challenger shareholders voting in favour of the special resolution at the separate general meeting.

The court meeting and the general meeting are each to be held at the company's registered office at The Engine House, Alexandra Road, Castletown, Isle of Man, IM9 1TG, on Nov. 26, 2025. The court meeting will start at 12 p.m. and the general meeting will start at 12:15 p.m. (or as soon thereafter as the court meeting has concluded or been adjourned).

Recommendation

The independent Challenger directors, who have been so advised by Gneiss Energy as to the financial terms of the acquisition, consider the terms of the acquisition to be fair and reasonable. In providing advice to the independent Challenger directors, Gneiss Energy has taken into account the commercial assessments of the independent Challenger directors. Gneiss Energy is providing independent financial advice to the independent Challenger directors for the purposes of Rule 3 of the Takeover Code.

Accordingly, the independent Challenger directors have unanimously recommended that scheme shareholders vote in favour of the scheme at the court meeting and Challenger shareholders vote in favour of the special resolution at the general meeting as the independent Challenger directors who hold Challenger shares have irrevocably undertaken to do in respect of 18,077,719 Challenger shares in total, representing in aggregate approximately 7.25 per cent of Challenger's ordinary share capital in issue as at the on the latest practicable date prior to commencement of the offer period. These irrevocable undertakings remain binding in the event an alternate or higher competing offer is made for Challenger by a third party.

As required by and solely for the purposes of Rule 16.1 of the Takeover Code, Gneiss Energy has (in its capacity as independent adviser to Challenger for the purposes of Rule 3 of the Takeover Code) advised the independent Challenger directors that the terms of the loan agreement are on market terms and are fair and reasonable as far as the independent Challenger shareholders are concerned.

Robert Bose, a non-executive director of Challenger, is the chief executive officer, a director and shareholder in Sintana and is also the managing member of Charlestown, which is a shareholder in both Sintana and Challenger and is therefore not considered by Challenger to be independent for the purposes of the acquisition. As a result, Mr. Bose has not been treated as an independent Challenger director and has not participated in the consideration of the acquisition by the independent Challenger directors or the decision of the independent Challenger directors to recommend the scheme.

Furthermore, Mr. Bose is also not considered by Sintana to be independent for the purposes of the acquisition. As a result, prior to any negotiations taking place, the Sintana board formed a special committee of non-interested directors comprising Keith Spickelmier and Douglas Manner to review, evaluate, consider and oversee the acquisition, including negotiating its terms and parameters.

The special committee engaged Pareto as its independent financial adviser in connection with the acquisition. Pareto was selected by the special committee on the basis of its independence, capabilities, credentials, reputation, and associated financial and valuation expertise. Pareto provided a fairness opinion to the special committee in respect of the acquisition, which was delivered in advance of publication of the announcement of the acquisition. The fairness opinion was used to support a recommendation by the special committee to the board of directors of Sintana (excluding Mr. Bose), who voted unanimously (again excluding Mr. Bose) in favour of the acquisition.

Timetable

The scheme document contains an expected timetable of principal events in relation to the scheme, which is also set out in the appendix to this announcement. If any of the dates and/or times in this expected timetable change, the revised dates and/or times will be notified to Challenger shareholders by an announcement through a regulatory information service, with such announcement also being made available on Challenger's website.

The scheme remains conditional on the approval of the requisite majority of eligible scheme shareholders at the court meeting, the requisite majority of eligible Challenger shareholders at the general meeting, the satisfaction or (if capable of waiver) waiver of the other conditions set out in the scheme document, and the sanction of the court.

Listing of new Sintana shares and cancellation of admission of Challenger shares on AIM (Alternative Investment Market)

Application will be made to the TSX Venture Exchange for admission of the new Sintana shares. It is expected that admission will become effective and dealings for normal settlement in the new Sintana shares will commence at or shortly after 8 a.m. Toronto time on the business day following the effective date.

Prior to the scheme becoming effective, application will be made by Challenger to the London Stock Exchange for the cancellation of the admission of the Challenger shares to AIM to take effect on or shortly after the effective date. The last day of dealings in Challenger shares on AIM is expected to take place on Dec. 10, 2025, the business day immediately prior to the effective date and no transfers shall be registered after 6 p.m. on that date. By 8 a.m. on Dec. 12, 2025, share certificates in respect of Challenger shares shall cease to be valid and entitlements to Challenger shares held within the CREST system shall be cancelled.

It is also proposed that, following the effective date and after its shares are delisted, Challenger will be reregistered as a private limited company.

Sintana AIM admission

As part of the acquisition, Sintana intends to seek admission of the Sintana shares (including the new Sintana shares) to trading on AIM as soon as practicable after the effective date. Obtaining the dual listing is not a condition to the scheme.

Legal advisers

In connection with the acquisition, Clyde & Co LLP is acting as U.K. legal adviser to Challenger and SW Legal Ltd. is acting as Isle of Man legal adviser to Challenger. Pinsent Masons LLP is acting as U.K. legal adviser to Sintana and Fogler Rubinoff LLP is acting as Canadian legal adviser to Sintana.

About Sintana Energy Inc.

The company is engaged in petroleum and natural gas exploration and development activities in six petroleum exploration licences in Namibia, including five offshore located variously in the Orange and Walvis basins, as well as in Colombia's Magdalena basin. Additionally, upon completion of a previously announced transaction, Sintana will have exposure to a licence in Angola's emerging onshore Kwanza basin. Sintana's strategy is to acquire and manage a portfolio of exposures to superior-quality assets with substantial value potential.

We seek Safe Harbor.