Rio Tinto–Glencore mega-merger collapse: portfolio and project signals for miners
Reviewed by Joe Ashwell

First reported on MINING.com
30 Second Briefing
Rio Tinto has walked away from merger talks with Glencore that would have created a $232 billion mining giant controlling about 7% of global copper output, after rejecting a structure under which Rio would hold the chair and CEO roles and pro forma control. Glencore argued the terms and proposed share-exchange ratio, reportedly targeting roughly 40% ownership, materially undervalued its copper business and overall contribution. The collapse, the third failed attempt since 2008, triggered share price falls of up to 11% for Glencore and 2.5% for Rio in London trading.
Technical Brief
- Glencore sought an exchange ratio giving its shareholders ~40% of the merged entity’s equity.
- Jefferies flagged “price and governance disagreements” as the core blockers after weeks of negotiations.
- Rio’s board concluded no merger or “other business combination” with Glencore could deliver sufficient shareholder value.
- Glencore argued the proposed governance and economics materially undervalued its copper business and overall contribution.
- Had it proceeded, the group would have been the world’s largest copper producer with ~7% global output.
- Rio is separately expanding copper exposure via projects including the Resolution Mine in Arizona, offsetting iron ore concentration.
Our Take
The collapse of the Rio Tinto–Glencore deal comes just days after our coverage of Rio Tinto shoring up its share structure for a potential merger, underscoring how quickly board and investor sentiment can swing on large-cap M&A in iron ore, coal and copper.
Glencore’s parallel moves in the DRC – including the proposed 40% sell-down of Mutanda and KCC to the Orion Critical Mineral Consortium – suggest it still has options to monetise copper and cobalt exposure without a Rio Tinto tie-up, which may ease pressure to pursue another mega‑merger in the near term.
Across the 914 Mining stories in our database, only a handful involve potential combinations that would control more than 5% of global copper output, so the end of a deal that might have concentrated around 7% leaves more room for mid-tier copper producers to compete for growth assets in Chile, Africa and Latin America.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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