Placing and Proposed Subscription for £1,000,000

("Tertiary" or the "Company")

4 June 2026

Placing and Proposed Subscription to raise £1,000,000

Tertiary Minerals plc (AIM: TYM), the explorer focused on energy transition and precious metals in Zambia and Nevada, is pleased to announce that it has raised £985,000 before expenses through a placing (the "Placing") of 1,970,000,000 new ordinary shares of 0.01 pence each in the Company (the "Placing Shares") at a price of 0.05 pence per share (the "Placing Price") as detailed below. The Placing was made with institutional investors and high net worth individuals and was arranged through the Company's joint brokers, SP Angel Corporate Finance LLP ("SP Angel") and AlbR Capital Limited ("AlbR").

The Company is currently in a close period as it will release its interim results to 31 March 2026 ("Interim Results") before the end of June 2026. Certain Directors of the Company have therefore indicated their intention to subscribe an additional amount of £15,000 in aggregate for an additional 30,000,000 new ordinary shares as detailed below, on the same terms as the Placing once the Company is no longer in a close period.

Commenting today, Managing Director Richard Belcher said:

"I would like to take the opportunity to thank existing and new shareholders for their support. This capital raise is designed to further advance work on our flagship Target A1 silver oxide discovery. This will include drilling to both infill and test mineralisation extensions, along with metallurgical testwork with the aim of delineating a maiden Mineral Resource Estimate by the end of this year."

Placing Details

The Placing comprises a placing of 1,970,000,000 new ordinary shares at the Placing Price. The Placing Price represents a discount of 17% to the closing bid-price on 3 June 2026 and the Placing Shares represent approximately 28% of the Company's issued ordinary share capital as enlarged by the Placing. The Placing is conditional on Admission.

The Placing Shares are being issued under the Company's existing share issue authorities.

Under the terms of their engagement, SP Angel and AlbR will be issued with a total of 98,500,000 warrants. Each warrant will entitle the holder to subscribe for one new ordinary share at the Placing Price at any time within 12 months.

Directors' Intentions

Under the AIM Rules for Companies ("AIM Rules"), the Directors have not been able to participate in the fundraise as the Company is currently in a close period by reason of the upcoming publication of its Interim Results. Certain directors have, however, indicated an intention to subscribe for a total of 30,000,000 new ordinary shares at the Placing Price for an aggregate amount of £15,000 (the "Subscription") as follows.

· Richard Belcher (Managing Director): £5,000

· Mike Armitage (Non-Executive Director): £10,000

As directors of the Company, Drs Belcher and Armitage are "related parties" of the Company under the AIM Rules for Companies (the "AIM Rules"). As a result, any subscription for shares once the Company is no longer in a close period constitutes a related party transaction pursuant to Rule 13 of the AIM Rules and will therefore be conditional on Mr. Donald McAlister and Mr Patrick Cheetham, the independent Directors in this matter, being satisfied at that time that the terms of the Directors' subscriptions are reasonable in so far as the Company's shareholders are concerned.

A further announcement will be made regarding any such subscription.

Admission

The Placing Shares will rank pari passu with the Company's existing ordinary shares. An application has been made to the London Stock Exchange for admission of the Placing Shares to trading on AIM. Admission is expected to occur at 8.00 a.m. on or around 9 June 2026. 

Use of Proceeds

The net funds raised will be applied to drilling and technical studies at the Mushima North Target A1 silver oxide discovery with the aim of producing a maiden JORC Mineral Resource Estimate for this by the end of 2026 and for general working capital.

Total Voting Rights

Following Admission of the Placing Shares, the Company's enlarged issued share capital will be 7,124,355,727 ordinary shares.

The Company holds no ordinary shares in treasury. The total number of voting rights in the Company will therefore be 7,124,355,727 following Admission and this figure may then be used by shareholders as the denominator for the calculations by which they determine if they are required to notify their interest in, or a change to their interest in, the Company under the FCA's Disclosure Guidance and Transparency Rules.

Further Information:

Market Abuse Regulation

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulation (EU) No. 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 ('MAR'). Upon the publication of this announcement via Regulatory Information Service ('RIS'), this inside information is now considered to be in the public domain.

About Tertiary Minerals plc

Tertiary Minerals plc (AIM: TYM) is an AIM-traded mineral exploration and development company whose strategic focus is on energy transition metals. The Company's projects are all located in stable and democratic, geologically prospective, mining-friendly jurisdictions. Tertiary's current principal activities are the discovery and development of copper and precious metal mineral resources in Zambia and Nevada, USA.