Mineral Resources (MinRes) has moved closer to sealing a landmark lithium partnership with Korean giant POSCO Holdings, cementing the future of two of Australia’s top lithium mines.

The investment agreement formalises POSCO’s planned acquisition of a 30 per cent stake in MinRes’ operational lithium arm, to be housed in a new entity, LithCo. The venture will hold MinRes’ existing 50 per cent interests in the Wodgina and Mt Marion mines, two of Australia’s premier hard rock lithium assets.

While the deal was first outlined in November 2025, the execution of binding documentation marks a critical milestone. Completion is now expected in the first half of the 2027 financial year, reflecting the time required for regulatory approvals and a corporate restructure to establish the joint venture.

“We are pleased to execute the key transaction documents with POSCO Holdings, a critical step in progressing this transaction,” MinRes managing director Chris Ellison said.  “We look forward to working with POSCO Holdings to finalise all outstanding matters and bring this to completion as soon as possible.”

The partnership represents what Ellison said is a landmark investment by a major Korean company into Australian lithium, and MinRes remains committed to ensuring that Wodgina and Mt Marion reach their full potential as two of the world’s best hard rock lithium assets.

POSCO Holdings president Ju-Tae Lee said the partnership is highly meaningful in that it combines MinRes’ mining and operational capabilities with POSCO Holdings’ downstream processing expertise, contributing to the stabilisation of the global battery materials supply chain.

“Based on the strong mutual trust between the two companies, we will continue to strengthen our long-term partnership in the global lithium market,” he said.

POSCO Holdings will acquire its 30 per cent interest, effectively 15 per cent of each mine at an underlying level, for $1.2 billion ($US765 million), valuing MinRes’ 50 per cent stake in the two mines at about $3.9 billion.

MinRes will retain a 70 per cent interest and continue to operate both mines under existing agreements with Albemarle Corporation at Wodgina and Jiangxi Ganfeng Lithium at Mt Marion.

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