Company Announcements

15 September 2025

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

Commercial Trading Launch and International Sales

Aterian plc (LSE: ATN), the critical mineral exploration and development company, is pleased to announce the launch of expanded trading operations in the Republic of Rwanda ("Rwanda"), marked by the first consignment of responsibly sourced tantalum-niobium ("Coltan") concentrate transferred to the Company's global trading partner.

Aterian's partnership with a leading metals and minerals trading house with a global presence, specialising in non-ferrous and speciality materials, provides Aterian with an established international sales and marketing platform, enabling the Company to scale rapidly while securing access to a wide network of downstream buyers.

Following the completion of due diligence by our partner and extensive product trials and compliance checks with a coordinated group of OECD-aligned artisanal and small-scale mining suppliers, Eastinco Ltd (Aterian's wholly owned Rwandan trading subsidiary) has now activated its responsibly sourced supply chain of tantalum and niobium and has initiated commercial sales.

To accelerate this expansion, Aterian has secured a US$250,000 mezzanine loan facility, which has been fully drawn down and deployed into trading operations. This capital is dedicated to the acquisition of responsibly sourced Rwandan mineral concentrates.

Aterian CEO, Simon Rollason, commented,

"The successful completion of supplier trials and compliance checks, combined with the injection of new trading capital, enables us to now move forward at pace. We anticipate a significant increase in trading volumes over the coming weeks as we activate multiple supply relationships and scale procurement operations with our trade finance partners. This is a pivotal moment for our trading business, laying the commercial foundation for growth across the region. With our operations, risk management systems and partnerships now in place, we are confident in our ability to demonstrate complete traceability compliance whilst building a robust and high-integrity supply chain that can support substantial volume growth and underpin long-term revenue generation for the Group."

Responsible Sourcing & Growth

All mineral supplies handled by Aterian are sourced in accordance with the International Tin Supply Chain Initiative (ITSCI) and comply fully with the OECD Due Diligence Guidance. Rigorous on-site audits, mine origin verification, and conflict-free checks underpin the Company's commitment to responsible sourcing.

This partnership not only validates Aterian's trading model but also demonstrates the commercial pathway to build a vertically integrated exploration and trading platform for critical minerals across East Africa. The Company has implemented rigorous onboarding and audit procedures to ensure that each supplier has been thoroughly vetted across operational, legal, and ethical criteria, including on-site assessments, verification of mine origin, and confirmation of conflict-free status. These checks will be ongoing and were a critical step to securing sufficient supply volumes. This commitment to traceability and responsible sourcing not only safeguards Aterian's reputation but also positions the Group as a reliable and transparent partner to downstream international buyers, who are increasingly focused on ESG-aligned procurement.  Export sales with container-sized volumes will now commence.

Further updates on trading performance and supply expansion will be provided in due course.

Our Focus Product: Coltan (Tantalite - Niobium)

Tantalite is a dense, black to brownish mineral that is a major source of tantalum, a rare, hard and highly corrosion-resistant metal widely used in modern electronics and other high-tech applications. Tantalite is part of the columbite-tantalite mineral group, often referred to as coltan, and typically contains tantalum (Ta) and niobium (Nb) in varying proportions.

Tantalum is primarily used in electronic components, such as capacitors and high-performance resistors, particularly in smartphones, laptops, gaming consoles, medical devices, and aerospace technology. Niobium is used in steel alloys, superconductors, and specialised electronics.

Key terms of the loan capital include:

·      Principal Amount: US$250,000

·      Interest Rate & Fees: 20.0% interest and 2% trading fees

·      Term: Initial three months, extendable by mutual agreement on a quarterly basis

·      Guarantee: Aterian plc guarantees the performance of Eastinco Ltd under the facility

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

For further information, please contact:

Aterian Plc:

Charles Bray, Executive Chairman - charles.bray@aterianplc.com

Simon Rollason, Director - simon.rollason@aterianplc.com

Financial Adviser and Joint Broker:

Novum Securities Limited

David Coffman / Anastassiya Eley

Colin Rowbury

Tel: +44 (0)207 399 9400

Joint Broker:

SP Angel Corporate Finance LLP

Ewan Leggat / Adam Cowl 

Tel: +44 20 3470 0470

Financial PR:

Bald Voodoo - ben@baldvoodoo.com

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

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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.

The Company has entered into a joint venture agreement with Rio Tinto Mining and Exploration Limited. Rio Tinto is earning into the HCK project in southern Rwanda, exploring and developing a lithium-tantalum-niobium-tin mining operation. The Company also holds an exploration licence in Rwanda. Aterian has a portfolio of multiple copper-silver (+ gold) and base metal projects in Morocco. Aterian holds a 90% interest in Atlantis Metals. This private, Botswana-registered company holds ten mineral prospecting licences for copper-silver in the world-renowned Kalahari Copperbelt and three for lithium brine exploration in the Makgadikgadi Pans region.

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.