NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION, IN WHOLE OR IN PART, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF THAT JURISDICTION

London, 6 December 2022

Publication of a Supplementary Prospectus

Nostrum Oil & Gas PLC (LSE: NOG) ("Nostrum" or the "Company"), an independent oil and gas company engaging in the production, development and exploration of oil and gas in the pre-Caspian Basin, announces that the Financial Conduct Authority (the "FCA") has today approved, and the Company has publi

shed, a supplementary prospectus (the "Supplementary Prospectus"), which is in relation to the prospectus issued by the Company on 14 October 2022 (the "Prospectus"). The Prospectus was published in connection with the proposed restructuring of the Group's US$725 million 8.0% Senior Notes due July 2022 and the US$400 million 7.0% Senior Notes due February 2025 (the "Restructuring").

The publication of this Supplementary Prospectus is a regulatory requirement under the Prospectus Regulation Rules, following the occurrence of the events referred to in the Supplementary Prospectus.

Capitalised terms not defined in this announcement shall have the meaning given to them in the Supplementary Prospectus. A copy of the Supplementary Prospectus is available free of charge on the Company's website at www.nostrumoilandgas.com and upon request sent to ir@nog.co.uk.

LEI: 2138007VWEP4MM3J8B29

Further information

For further information please visit www.nog.co.uk

Further enquiries:

Nostrum Oil & Gas PLC

Thomas Hartnett - Chief Legal Officer / Company Secretary

ir@nog.co.uk

White & Case LLP

Allan Taylor (ataylor@whitecase.com)

+44 (0) 207 532 1000

WCProjectNewport@whitecase.com

Instinctif Partners - UK

Tim McCall

Galyna Kulachek

Sarah Hourahane

+ 44 (0) 207 457 2020

nostrum@instinctif.com

Notifying person

Thomas Hartnett

Company Secretary

About Nostrum Oil & Gas

Nostrum Oil & Gas PLC is an independent oil and gas company currently engaging in the production, development and exploration of oil and gas in the pre-Caspian Basin. Its shares are listed on the London Stock Exchange (ticker symbol: NOG) and the Kazakhstan Stock Exchange (ticker symbol: GB_NTRM). The principal producing asset of Nostrum Oil & Gas PLC is the Chinarevskoye field, that is being operated by a wholly-owned subsidiary of Nostrum Oil & Gas PLC - Zhaikmunai LLP, who is the sole holder of the subsoil use rights with respect to the development of the field.

Forward-Looking Statements

Some of the statements in this document are forward-looking. Forward-looking statements include statements regarding the intent, belief and current expectations of the Company or its officers with respect to various matters. When used in this document, 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 Company or any other entity, and shareholders of the Company are cautioned not to place undue reliance on the forward-looking statements. Save as required by the relevant listing rules and applicable law, the Company does not undertake to update or change any forward-looking statements to reflect events occurring after the date of this announcement.

Disclaimer

This announcement is not intended to and does not constitute or form part of any offer to sell or invitation to purchase, otherwise acquire, subscribe for, sell or otherwise dispose of, any securities or the solicitation of any vote or approval in any jurisdiction pursuant to the proposals set out herein or otherwise, nor shall it (or the fact of its distribution) form the basis of, or be relied on in connection with, any contract therefor or be considered a recommendation that any investor should subscribe for or purchase or invest in any securities.

Any such offer or invitation will be made solely by means of a prospectus as supplemented by a supplementary prospectus to be published by the Company in due course. This announcement has not been examined or approved by the FCA or any other regulatory authority. The distribution of this announcement in certain jurisdictions may be restricted by law and therefore persons into whose possession this announcement comes should inform themselves about and observe any such restrictions. Any failure to comply with these restrictions may constitute a violation of the securities laws of any such jurisdiction.

The securities referred to herein have not been and will not be registered under the US Securities Act of 1933 as amended (the "Securities Act") or under any US state securities laws and may not be offered or sold within the United States unless any such securities are registered under the Securities Act or an exemption from the registration requirements of the Securities Act and any applicable state laws is available.

Neither the content of the Company's website nor any website accessible by hyperlinks to the Company's website is incorporated in, or forms part of, this announcement.