Diversified major Rio Tinto has ruled out a potential merger or business combination with Glencore, saying it is no longer considering a transaction after determining that it would not deliver sufficient value to shareholders.

In a statement on Thursday, the mining company said it had assessed the opportunity in line with the capital allocation framework outlined at its December 2025 Capital Markets Day, which prioritises long-term value creation and shareholder returns.

“Rio Tinto has determined that it could not reach an agreement that would deliver value to its shareholders,” the company said.

The announcement follows Rio’s earlier disclosure in January that it was evaluating a possible transaction with Glencore. A merger would created the world's largest mining company with a combined market value of nearly $207-billion.

Under UK takeover rules, a potential bidder has 28 days from being identified to either announce a firm intention to make an offer, walk away or seek an extension. The deadline for a potential offer was Thursday.

In its response, Glencore said the proposed terms of a potential transaction with Rio Tinto would have undervalued its contribution to a combined group.

"The key terms of the potential offer were Rio Tinto retaining both the chairman and chief executive officer roles and delivering a proforma ownership of the combined company which, in our view, significantly undervalued Glencore's underlying relative value contribution to the combined group, even before consideration of a suitable acquisition control premium," Glencore said.

The miner also noted that the structure did not adequately reflect the long-term value of its copper business, growth pipeline or potential synergies.

Glencore said it had concluded that the proposal was not in the best interests of its shareholders.

The diversified miner highlighted the strength of its standalone investment case, citing its diversified commodity portfolio, leading marketing business and growing exposure to transition-related metals.

It also pointed to improvements in operating structures, delivery of production within guidance for a second consecutive year, and continued upgrades to its asset base.

Glencore said it remained focused on delivering its 2026 priorities, meeting operational targets and advancing organic growth projects to support long-term shareholder value.