NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN OR INTO ANY JURISDICTION WHERE IT IS UNLAWFUL TO RELEASE, PUBLISH OR DISTRIBUTE THIS ANNOUNCEMENT

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION

                                                       Nostrum Oil & Gas PLC                                                      

(incorporated under the laws of England and Wales)

AGREEMENT TO SELL KAZAKHSTAN OPERATIONS

Sale

Nostrum Oil & Gas PLC (the "Company", and together with its subsidiaries, the "Group") announces today that the Company's indirect subsidiary company, Nostrum Oil & Gas Finance B.V. (the "Seller"), has entered into a sale and purchase agreement ("SPA") to sell the Seller's participating interests in the charter capital of Zhaikmunai LLP ("Zhaikmunai") and POSITIV Invest LLP ("POSITIV") (together with the Seller's rights under certain related loan agreements) to Altaris Holding Ltd. (the "Buyer") (the "Sale"), which is owned by Fincraft Energy Holding Limited and Alturion Holding Limited.

The total consideration for the Sale is U.S.$304,600,000 (the "Purchase Price"), subject to any adjustments relating to net working capital, net debt and cash positions of the target entities on completion.

The Group's unrestricted cash balance is mostly outside of the Sale, and there should be no material liabilities remaining between the above entities (Zhaikmunai and POSITIV) and the rest of the Group upon completion.

As more particularly described below, if the conditions to the Sale are satisfied and the Sale completes, the Group expects to repay all outstanding amounts with respect to the senior secured notes issued by the Seller (the "SSNs") in full and the outstanding amounts in respect of the senior unsecured notes issued by the Seller (the "SUNs", and together with the SSNs, the "Notes") in part. The Board of the Company therefore considers that, in light of the recent maturity of the Notes on 30 June 2026 and the Group being unable to repay the amounts due under the Notes at that time, the overall transaction described in this announcement will result in the best outcome for the Group and its stakeholders.

The Company expects to begin an orderly wind-down process of the Group as soon as reasonably practicable after completion of the Sale, subject to the required SUN holder approvals, wind-down costs and other contingencies.

Conditions, Potential Seller Liability and Escrow Arrangements

The Sale is subject to various conditions precedent, including (but not limited to) merger control clearance pursuant to applicable Kazakhstan law, consents and waivers from the Ministry of Energy of the Republic of Kazakhstan and Qazaq Gaz, applicable shareholder and pre-emption processes in relation to POSITIV, SUN holder approvals and confirmed financing for the Buyer.

The SPA provides for a long stop date by which conditions precedent must be satisfied of 15 September 2026, which may be automatically extended once by two months if the conditions precedent have not been satisfied or waived by that date.

There can be no certainty that all the conditions precedent to the Sale will be satisfied or waived, and whether or when the Sale will complete.

The Sale is not conditional on and does not require the approval of the Company's shareholders.

It has been agreed to hold U.S.$10,000,000 of the Sale consideration in an escrow account in connection with any potential claims under or in connection with the SPA for a period of at least six (6) months.

Stakeholder Recovery and SUN Consent Solicitation

Based on the Purchase Price, the Group's capital structure and cash position, and current expectations of transaction costs and the outcome of the post-Sale orderly wind-down, if the Sale completes, the Purchase Price would enable repayment of the SSNs in full and repayment of the SUNs in part.

As the SSNs will be repaid in full, no consent solicitation exercise will be launched with respect to the SSNs and the SSNs will be redeemed in accordance with their terms on or about the completion date of the Sale, and any and all guarantees and security provided by, or in respect of the shares of, Zhaikmunai and POSITIV and any of their respective direct or indirect subsidiaries (as applicable) under and in respect of the SSNs shall be capable of falling away without any SSN holder approval.

The Group currently targets (but provides no assurance) that SUN holders will receive an initial repayment of around U.S.$150,000,000. The Group currently estimates (but provides no assurance) that there could follow some further, materially smaller repayment(s) of the outstanding principal amount of the SUNs over time, depending upon working capital and net cash adjustments, potential claims under the SPA, wind-down costs, and the outcome of any contingent assets and liabilities of the Group.

The Group expects to shortly launch a consent solicitation exercise seeking the consents of eligible holders of the SUNs in connection with the Sale to, among other things, release any and all guarantees and security provided by, or in respect of the shares of, Zhaikmunai and POSITIV and any of their respective direct or indirect subsidiaries (as applicable) under and in respect of the SUNs, and to approve a mechanism for achieving a solvent wind-down of the Group following the expiry of the liability period under the SPA.

The Group does not currently expect that residual proceeds available for distribution to ordinary shareholders of the Company will be material, if any. However, the Group does not rule out the possibility of a final distribution to shareholders at the end of the Group's orderly wind-down process, depending on final transaction proceeds, creditor recoveries, wind-down costs, retained liabilities, contingent assets and other contingencies.

Ad Hoc Forum

The Group has been in discussions with an ad hoc group of beneficial owners of the SUNs, which represent more than 50% of the SUNs (the "Ad Hoc Forum") regarding the Sale and the related consent solicitation and wind-down proposals and the Ad Hoc Forum has expressed its support for the Sale and the subsequent orderly wind-down of the Group. Formal approval of eligible SUN holders will be sought through the consent solicitation process described above, and there can be no assurance that such approval will be obtained.

Dated: 17 August 2026

LEI of Nostrum Oil & Gas PLC: 213800SGF6UKA42KSB50

Person Responsible

The person responsible for arranging the release of this announcement on behalf of the Company is Robin Storey, Chief Legal Officer and Company Secretary.

Further Information

For further information please visit www.nostrumoilandgas.com

Further Enquiries

Nostrum Oil & Gas PLC

Yelena Zhuravleva, CFO

[email protected]

TEAM LEWIS

Galyna Kulachek

+ 44 (0) 20 7802 2664

[email protected]

About Nostrum Oil & Gas

Nostrum Oil & Gas PLC is an independent energy company with gas processing infrastructure and an export hub in north-west Kazakhstan. Its shares are listed on the London Stock Exchange (ticker symbol: NOG). The principal producing asset of Nostrum Oil & Gas PLC is the Chinarevskoye field which is operated by its wholly-owned subsidiary Zhaikmunai LLP, which is the sole holder of the subsoil use rights with respect to the development of the Chinarevskoye field. The Company also owns an 80% interest in Positiv Invest LLP, which holds the subsoil use rights for the "Kamenskoe" and "Kamensko-Teplovsko-Tokarevskoe" areas in the West Kazakhstan region (the Stepnoy Leopard fields).

Forward-Looking Statements

Some of the statements in this announcement are forward-looking. Forward-looking statements include statements regarding the intent, belief and current expectations of the Group or its officers with respect to various matters. When used in this announcement, the words "expects", "believes", "anticipates", "plans", "may", "will", "should" and similar expressions, and the negatives thereof, are intended to identify forward-looking statements. Such statements are not promises nor guarantees and are subject to risks and uncertainties that could cause actual outcomes to differ materially from those suggested by any such statements.

No part of this announcement constitutes, or shall be taken to constitute, an invitation or inducement to invest in the Group or any other entity, and shareholders of the Group are cautioned not to place undue reliance on the forward-looking statements. Save as required by the relevant listing rules and applicable law, the Group does not undertake to update or change any forward-looking statements to reflect events occurring after the date of this announcement.