Participation in the Dos Amigos Copper-Gold Project in Chile through an Investment in Canada's Tintina Mines-Proactive Project Origination Through a Strategic Partnership with the G Mining Group-

Sumitomo Corporation (Head Office: Chiyoda-ku, Tokyo; Representative Director, President and Chief Executive Officer: Shingo Ueno) has participated in the Dos Amigos copper-gold project (hereinafter the “Project”) in the Atacama Region of Chile through a special purpose vehicle (SPV) funded with the G Mining Group, on a 50:50 basis, under its strategic partnership. The SPV subscribed for approximately C$48 million of Tintina Mines Limited’s (hereinafter “Tintina”) C$91 million private placement. Tintina is a Canadian mine development company listed on the TSX Venture Exchange. Following the completion of the financing, the SPV holds approximately a 25% equity interest in Tintina, providing an effective economic interest of approximately 25% in the Project through its investment in Tintina effectively. The proceeds funded the acquisition of additional ownership interests in the Project resulting in Tintina obtaining 100% ownership, and will fund the Project’s advancement towards a final investment decision.

The Project is centered on the development of a copper-gold deposit in the Atacama Region, northern Chile. A Preliminary Economic Assessment (PEA) released in 2026 has identified measured & indicated mineral resources of approximately 101 million metric tons and inferred mineral resources of approximately 256 million metric tons, and an expected mine life of approximately 25 years. Mining development is already underway in the surrounding area, allowing the Project to benefit from existing transportation and power infrastructure. Its relatively low elevation is another advantage from a development perspective. Furthermore, promising exploration potential in adjacent areas points to significant medium- to long-term growth opportunities.

Sumitomo Corporation has identified copper - a mineral resource for which demand is expected to continue growing - as a key strategic focus. In addition to participating in conventional large-scale development projects, the company is strengthening its mineral resources business platform by originating promising projects and enhancing their value. As part of this initiative, Sumitomo Corporation has established a strategic partnership with the G Mining Group for upstream copper investments.

Founded in Canada in 2006, the G Mining Group provides engineering and construction services for mine development. Leveraging its advanced technical expertise and innovative project delivery method, the group has successfully delivered multiple mine development projects on schedule and within budget for major mining companies.

As mining projects have grown increasingly complex in recent years, completing projects on schedule and within budget has become a key industry challenge. Sumitomo Corporation is proactively originating new investment opportunities by combining the business management expertise, industry knowledge, global network, and project structuring capabilities developed through its mineral resources business experiences with the G Mining Group’s advanced mine development and construction capabilities. The Project was identified and structured through G Mining Capital Inc., an upstream copper business development platform jointly established and operated by Sumitomo Corporation and the Gignac family. It represents a tangible outcome of our collaborative activities.

Through its participation in the Project, Sumitomo Corporation will contribute to the stable supply of copper resources, and the company will seek to generate a strong pipeline of new business opportunities and further strengthen its mineral resources business platform.

Dos Amigos Project Overview (projected/planned)

Tintina Mines Limited Company Overview

G Mining Group Overview

Related Information:
Completion Conditions Met for Project Financing of the Quebrada Blanca Phase 2 Project in Chile