Rio Tinto Ltd said on Wednesday it has taken a majority stake in Nemaska Lithium, the Quebec-based lithium developer, raising its ownership to 53.9% while the Government of Quebec holds the remaining 46.1%.
In early trading on Thursday, Rio shares gained just over 2%, reaching A$169.630, a move that helped lift the ASX 200 by roughly 1%.
The miner stated it intends to build a vertically integrated lithium operation in Quebec, spanning the extraction of ore through to chemical processing. The stated objective is to supply lithium to the North American electric vehicle industry.
As part of the plan, Rio Tinto will invest more than $300 million in Nemaska in 2026. The Government of Quebec has committed to invest an additional $200 million in the company, Rio said.
Rio initially acquired a 50% interest in Nemaska when it completed its acquisition of Canadian miner Arcadium in early-2025. The company has notably increased its investment focus on lithium production over the past five years, citing expectations of strong demand from the electric vehicle sector.
Lithium remains a central input for EV battery production, and demand from the sector has been a major factor driving pronounced increases in lithium prices in recent years. Globally, Australia is identified as the largest producer of lithium, while Canada ranks eighth among producing countries. China holds the largest refining capacity for lithium, and several companies and governments have in recent years sought to diversify processing capacity away from the country.
Context and market reaction
The move to a majority stake in Nemaska is part of Rio Tinto's broader effort to secure upstream and downstream positions in the lithium value chain. The company's announced funding commitments for 2026, combined with Quebec's investment, underline a partnership approach to developing local lithium processing capacity targeted at North American EV manufacturers.