Rio Tinto and Glencore, two of the world’s largest mining companies, confirmed last week that they are in early discussions about a possible merger.

Glencore said that it “confirms that it is in preliminary discussions with Rio Tinto” regarding “a possible combination of some or all of their businesses”, adding that this “could include an all-share merger between Rio Tinto and Glencore”.

The language is deliberately cautious. It signals openness to a major transaction without committing to a full merger, a valuation, or a final structure.

Meanwhile Rio Tinto issued a parallel statement, saying the companies “have been engaging in preliminary discussions about a possible combination of some or all of their businesses, which could include an all-share merger between Rio Tinto and Glencore”. However, Rio added that “there can be no certainty that an offer will be made or as to the terms of any such offer”.

A combined Rio Tinto and Glencore entity would rank among the largest mining groups in history, with dominant positions across iron ore, copper, and other industrial commodities that underpin global growth and energy systems.

Coal remains the most sensitive issue. Glencore is a major coal producer, while Rio Tinto has largely exited the sector. That tension explains the repeated reference to “some or all of their businesses”, wording that leaves open the possibility of exclusions or asset sales if talks advance.

Regulatory approval would be another formidable hurdle. A transaction of this size would face scrutiny across multiple jurisdictions. Rio’s statement acknowledges this reality directly, when it notes that there is “no certainty that an offer will be made”.