21 September 2026

Aterian Plc
("Aterian" or the "Company")

CLN Conversion

Aterian Plc (LSE: ATN), the Africa-focused critical minerals exploration, development and trading company, announces the early conversion of a portion of outstanding Convertible Loan Notes ("CLN") through the issue of new ordinary shares in the Company following a conversion notice from a CLN holder.

The Company has approved the conversion of £90,000 of the CLN, pursuant to their terms.

The conversion amount will be satisfied through the issue of 360,000 new ordinary shares of £0.10 each in the capital of the Company ("Ordinary Shares") at a conversion price of 25 pence per Ordinary Share (the "Conversion Shares"). The Conversion Shares will rank pari passu in all respects with the Company's existing Ordinary Shares.

Application will be made for the Conversion Shares to be admitted to trading on the Main Market of the London Stock Exchange ("Admission") which is expected to be on or around 25 September 2026.

Total Voting Rights

Following Admission of the Conversion Shares, the Company will have 20,060,000 Ordinary Shares in issue, each carrying one voting right. The Company does not hold any Ordinary Shares in treasury.

Accordingly, the total number of voting rights in the Company will be 20,060,000. Shareholders may use this figure as the denominator for calculations by which they determine whether they are required to notify their interest in, or change to their interest in, the Company's share capital under the FCA's Disclosure Guidance and Transparency Rules.

- ENDS -

This announcement contains information which, prior to its disclosure, was inside information as stipulated under Regulation 11 of the Market Abuse (Amendment) (EU Exit) Regulations 2019/310 (as amended).

Engage directly with the Aterian PLC management team by asking questions, watching video summaries, and seeing what other shareholders have to say. Please navigate to our interactive investor hub here: https://aterianplc.com/s/fcf8eb

For further information, please visit the Company's website: www.aterianplc.com or contact:

Aterian Plc:

Charles Bray, Executive Chairman - [email protected]

Simon Rollason, Director - [email protected]

Financial Adviser and Joint Broker:

AlbR Capital Limited

David Coffman / Dan Harris

Colin Rowbury

Tel: +44 (0)207 7469 0930

Joint Broker:

SP Angel Corporate Finance LLP

Ewan Leggat / Devik Mehta

Tel: +44 20 3470 0470

Financial PR:

Bald Voodoo - [email protected]

Ben Kilbey
Tel: +44 (0)7811 209 344

Notes to Editors:

About Aterian plc

www.aterianplc.com

Aterian plc is an LSE-listed exploration and development company with a diversified African portfolio of critical metals projects.

Aterian plc is actively seeking to acquire and develop new critical metal resources to strengthen its existing asset base while supporting ethical and sustainable supply chains as the world transitions to a sustainable, renewable future. The supply of these metals is vital for developing the renewable energy, automotive, and electronic manufacturing sectors, which are increasingly important in reducing carbon emissions and meeting global climate ambitions.

Aterian has a portfolio of multiple copper-silver (+gold) and base-metal projects in Morocco. Aterian holds a 90% interest in Atlantis Metals, a private Botswana-registered company holding eleven mineral prospecting licences for copper-silver in the world-renowned Kalahari Copperbelt and three for lithium and salt brine exploration in the Makgadikgadi Pans region. The Company also holds an exploration licence in southern Rwanda, where it is evaluating the tantalum and niobium opportunity, in addition to further exploring for pegmatite-hosted lithium.

The Company's strategy is to seek new exploration and production opportunities across the African continent and to develop new sources of critical mineral assets for exploration, development, and trading.