CONSTELLATION OIL SERVICES HOLDING S.A. COSH PROSPECTUS / ADMISSION DOCUMENT

Constellation Announces Publication of Prospectus in Connection with Uplisting to Euronext Oslo Børs

21. May 2026 kl. 15:31

Luxembourg, 21 May 2026 - Reference is made to the stock exchange announcement published on 18 May 2026 regarding the application by Constellation Oil Services Holding S.A. ("Constellation" or the "Company") for the transfer of Constellation's existing depositary receipts (the "Securities") from Euronext Growth Oslo to Euronext Oslo Børs (the main list).

In connection with the contemplated listing, Constellation has prepared a prospectus which has now been approved by the Financial Supervisory Authority of Norway (the "Prospectus").

The Prospectus is available on the Company’s website (https://ir.theconstellation.com/investor-information/press-releases/).

It is expected that the Securities will start trading on Euronext Oslo Børs on Tuesday 26 May 2026 (under the ticker symbol "COSH" and ISIN Code NO0013597419). Simultaneously with the start of trading of the Securities on Euronext Oslo Børs, the Securities will be deregistered from, and will cease to trade on, Euronext Growth Oslo.

Advisers

Clarksons Securities AS and DNB Carnegie, a part of DNB Bank ASA, are acting as financial advisors to the Company in connection with the listing.

Advokatfirmaet Thommessen AS is acting as legal counsel to the Company.

Capient AS is acting as IR and communications advisor to the Company.

For further information, please contact:

Media: Thomas C. Høie, Capient constellation@capientco.com +45 29 93 54 54

Investor Relations Phone: +352 20 20 2401 ir@theconstellation.com www.theconstellation.com/ir

IR Team: Monique Fares / mfares@theconstellation.com João Gabriel Ratton / jratton@theconstellation.com Victor Mello Paranhos / vparanhos@theconstellation.com Joao Pedro Zakour Monteiro de Souza jdemonteiro@theconstellation.com

About Constellation

Constellation is a market leading provider of offshore oil and gas contract drilling services through its subsidiary Serviços de Petróleo Constellation S.A. (“Serviços de Petróleo Constellation”). With continuous operations since 1981, Serviços de Petróleo Constellation has built an unmatched reputation for excellence in offshore drilling services, obtaining ISO 9001, ISO 14001, ISO 45001, and API Spec Q2 certifications for its quality management, environmental and safety records and systems.

IMPORTANT NOTICE

This information is subject to the disclosure requirements pursuant to section 5-12 of the Norwegian Securities Trading Act and Euronext Oslo Rule Book II - Issuer Rules.