Australian miner Fortescue on Monday announced that it would acquire the remaining 64% of Canada-listed Alta Copper in a cash transaction that valued the copper developer at C$139-million, advancing its strategy to build a global copper portfolio.

Under a binding agreement, Fortescue would acquire the shares it did not already own in Alta Copper through a Canadian plan of arrangement, offering cash consideration of C$1.40 a share. The offer represents a 50% premium to Alta Copper’s 30-day volume-weighted average price (VWAP) and a 100% premium to the VWAP prior to the start of exclusive negotiations between the parties in November.

Fortescue currently holds about 36% of Alta Copper’s issued common shares and will acquire the balance through its wholly owned subsidiary, Nascent Exploration.

Alta Copper owns 100% of the Cañariaco copper project in northern Peru, located within an emerging porphyry belt that hosts a number of large exploration and development opportunities. The project covers about 91 km² and includes the Cañariaco Norte and Cañariaco Sur deposits, as well as the Quebrada Verde prospect.

The Cañariaco project hosts reported measured and indicated mineral resources of 1.1-billion tonnes at 0.42% copper-equivalent, with a further 0.9-billion tonnes at 0.29% copper-equivalent in inferred resources. A preliminary economic assessment completed in June last year outlined the potential for a long-life copper operation.

Fortescue said the transaction aligned with its critical minerals strategy, which prioritised the expansion of its copper portfolio and related exploration footprint. The company believes it is well positioned to advance the Cañariaco project, drawing on its established presence in Latin America since 2018, as well as its technical, permitting and community engagement capabilities.

Alta Copper’s board of directors and special committee have unanimously recommended that shareholders vote in favour of the transaction. Directors, officers and other shareholders representing about 12.5% of the issued shares have entered into voting support agreements backing the deal.

The transaction would require approval from Alta Copper shareholders at a meeting expected to be held in January, as well as court approval and other customary closing conditions.

Subject to these approvals, the transaction is targeted to close in the March quarter of 2026.