Alas, the proposed US$260 billion mega merger between Rio Tinto and Glencore remains just a dream. It again promised to reshape global mining, but a decade-long courtship has repeatedly collapsed under the weight of antitrust exposure, valuation gaps, cultural clashes and ESG baggage.
"Global miner Rio Tinto will not be taken over by rival Glencore because there is no value in it for shareholders and regulators will never let it happen," then-CEO Sam Walsh told reporters in late 2014.
When talks were finally torched again in 2026, Rio's board reverted to the same core message: it could not land terms that delivered returns in a way that justified the complexity and downside.
This piece traces the saga chronologically: from Glencore's first 2014 overture and Walsh's emphatic rejection, through a brutal downturn that made boards wary of blockbuster deals, to the latest cycle of 2024-26 negotiations driven by copper demand and the energy transition.
Along the way, remarks from CEOs, chairmen and prominent sell-side voices show how each side viewed the tie-up as simultaneously logical and structurally unworkable.
Where Rio saw a threat to its governance premium and ESG profile, Glencore saw a transformative path to re-rating - but neither could bridge the divide on price, control or coal.
Early approach
Glencore's first serious approach came in July 2014, when Ivan Glasenberg sounded out Rio about a combination that would have created an eye-watering US$160 billion mining and commodity marketing colossus - surpassing BHP in scale.
Rio's board batted it away within weeks.
"The Rio Tinto board, after consultation with its financial and legal advisers, concluded unanimously that a combination was not in the best interests of Rio Tinto's shareholders," the company said, confirming there had been "no further contact" with Glencore after it communicated that rejection.
The message from London and Melbourne was blunt: Rio preferred to stay independent and zero in on its own strategy rather than roll the dice on a risky tie-up.
Walsh soon went further, spelling out both valuation and regulatory obstacles in a Bloomberg Television interview.
"We're two totally different organisations," Walsh said.
"We're an organisation that's very focused on the long term. Glencore is a trading company, they're very short-term in focus. That's a very different philosophy to us."
He added that investors themselves were sceptical.
"Investors express confusion, saying, 'I don't understand why this is even being discussed, as it's simply not going to occur,'" Walsh remarked in a speech on consolidation among major miners.
He tied that scepticism to two pillars: the risk that Glencore wouldn't stump up a full control premium, and competition authorities who, in his words, “will simply not allow this to proceed”.
Walsh later called the combination a "poor match", while leaving the door open to asset-level transactions.
"There are no sacred cows," he said.
"If anybody, including Glencore, wants to come and make an offer that recognises the true value of assets … then of course we are going to take a look at it."
That nuance foreshadowed Rio's long-term preference for targeted bolt-ons over full-blown mergers.
Downturn and discipline
After the initial knockback, the commodity cycle turned sharply.
A PwC review of the sector, often cited in discussions of the mining downturn and M&A, noted that by 2015 the top 40 miners' market capitalisation had fallen by more than a third from its 2011 peak, with impairments surging and investors rewarding balance-sheet repair over expansion.
Moody's described the slump as "not a 'normal' one," arguing that over-investment, slowing Chinese demand and higher leverage would force companies to prioritise deleveraging and discipline.
That environment made jumbo tie-ups like GlenTinto all but untouchable.
Sector watchers framed the 2014-15 episode as a near-miss that had helped entrench conservative instincts.
Rio's own M&A track record didn't help. The company's infamous US$38 billion top-of-cycle acquisition of Canadian aluminium producer Alcan in 2007 - right before the GFC - still loomed large, and management wanted to prove it had learned from those write-down-heavy mis-steps.
In that context, pursuing a controversial all-share combination with a trader-coal house looked like a reputational and financial liability, even if the theoretical copper and marketing synergies were attractive.
On the Glencore side, Glasenberg continued to argue that heft and integration between marketing and mine-gate operations would drive long-term upside.
But the company's own headwinds - including pressure to reduce debt and questions about its thermal coal baggage and historic conduct - limited its room to launch a fresh overture at a price Rio's register would accept.
The result was a long pause: both sides fixated on their balance sheets and portfolios rather than re-engaging in talks.
Copper and climate
The next chapter opened as the energy transition reignited interest in copper and other "future-facing" metals.
S&P Global forecast that global copper demand could rise about 50% by 2040, with a potential supply deficit of more than 10 million tonnes (t) a year without new projects or higher recycling, making consolidation in copper-rich portfolios newly attractive.
Rio, with world-class iron ore but a relatively modest copper footprint, increasingly looked under-exposed, while Glencore owned a rich set of copper mines and development-stage assets but traded on a lower multiple due to coal and marketing-book volatility.
When talks first resurfaced in late 2024 under then-Rio CEO Jakob Stausholm, they collapsed over valuation and coal.
Glencore reportedly pushed for a ~40% stake in the combined group and wanted CEO Gary Nagle to run the show - a non-starter for Rio at the time.
But the idea never went away.
"Our goal is to become the biggest copper producer in the world," Nagle told investors at a December 2025 strategy day.
As Bloomberg reported when talks restarted in January 2026, Nagle's predecessor and mentor Glasenberg had been trying to engineer the deal "for nearly two decades."
This time it was Rio that re-initiated discussions.
The company had a new CEO in Simon Trott - selected specifically because the board wanted a leader more open to large-scale deals than Stausholm.
The two companies confirmed they were in preliminary discussions about an all-share buyout that would create a combined entity worth roughly US$207 billion at the time of announcement.
For Glencore, the attraction was straightforward: attach its marketing engine and red metal pipeline to Rio's larger, higher-quality asset base and stronger credit rating.
Andy Forster, senior investment officer at Argo Investments, captured the investor mood.
"The biggest question mark would be the culture of the two companies," Forster said.
"Glencore clearly has a trading background, is very opportunistic and results-focused."
Shareholders also zeroed in on coal and ESG as potential flashpoints.
"Coal would have to be divested to garner the support of the Australian shareholder base," Wilson Asset Management portfolio manager John Ayoub told Reuters.
Allan Gray analyst Tim Hillier, another Rio investor, struck a similar note of caution.
"It comes down to price, but if they have to pay a big premium there is a risk that a transaction could destroy some value for shareholders," Hillier said.
"Rio has a strong pipeline of internal high-growth projects. It's not clear why they need to look externally for things to do."
Those remarks sharpened the dilemma: Rio wanted base metals exposure and heft, but not at the cost of re-inheriting thermal coal or overpaying.
Regulatory shadows
Even as bankers pitched synergies, regulatory overhangs remained front and centre.
A Reuters analysis on asset sales to win over China reported that the combined group's concentration in red metal marketing and iron ore supply would trigger close scrutiny from Beijing's antitrust regulators, who had already forced Glencore-Xstrata to divest the Las Bambas copper project to a Chinese consortium as a condition of that 2013 deal's approval.
Lawyers quoted in similar coverage warned that China might again demand major copper or iron ore disposals, eroding the very benefits the super-merger was designed to capture.
National-interest reviews loomed too.
An S&P Global piece on what a Rio-Glencore merger means argued that Rio's Pilbara operations are of strategic importance to Australia and that any partial transfer of control to a Swiss-based commodity house would face intense scrutiny from Canberra's Foreign Investment Review Board.
Walsh's earlier warning - that regulators "will simply not allow this to proceed" - had anchored expectations that even a cleverly structured share-for-share deal would be politically fraught.
These anticipated hurdles fed directly into pricing discussions: if regulators were likely to demand divestments and concessions, how much synergy upside could you credibly bake into the model?
Final collapse
By early February 2026, after weeks of negotiation, the latest attempt fell apart.
Under UK takeover rules, Rio faced a 5 February deadline to either table a firm bid or walk away - it chose the latter.
"Rio Tinto has determined that it could not reach an agreement that would deliver value to its shareholders," the company said in a short statement.
The language echoed 2014 almost word-for-word.
The market scolded both parties: Glencore shares dropped 7% on the news; Rio dipped 2.6%.
Glencore's message was that it had balked at unfavourable terms rather than been rebuffed.
Reports indicated the sticking point was a roughly 62-38 pro forma split in Rio's favour - implying a ~30% premium for Glencore shareholders - but Glencore wanted closer to 40%.
"We concluded that the proposed acquisition on these terms is not in the best interests of Glencore shareholders," the company said in its own statement.
"It does not reflect our view on long-term, through-the-cycle relative value, including not adequately valuing our copper business and its leading growth pipeline."
Behind the scenes, sources briefed to Bloomberg said Glencore objected to a framework where Rio would retain both the chair and CEO roles without paying a conventional bid premium.
Market commentators were quick to frame the breakdown as a win for discipline over empire-building.
"There are various ways for Glencore to unlock value, but getting acquired at a premium in an all-share deal to form a combined company that could have been the 'go-to' stock in the sector would have been the simplest and most elegant path to a significantly higher share price," Jefferies analyst Christopher LaFemina said.
Wilson Asset Management's Ayoub welcomed the outcome.
"This reinforces Rio's disciplined approach to capital management," Ayoub told Reuters.
"We are very pleased to see Simon Trott pass his first test in the seat."
Under UK takeover rules, Rio is now barred from making another approach for six months unless Glencore consents or specific conditions are met.
For Glencore, the line was that its copper and marketing franchises deserved a higher bid - or a different counterparty.
What it shows
Viewed through a decade of aborted talks, the Rio-Glencore merger was both a compelling and unworkable mismatch.
Nagle and Glasenberg spent years trying to engineer what they saw as the most logical consolidation play in the sector - fusing marketing and mine-gate heft into a copper super-major for the energy-transition era.
Walsh and, later, Trott, along with their boards and key shareholders, saw too much downside in antitrust, coal, culture and governance, and never found a price or structure that squared those circles.
In the end, the courtship tells us as much about today's mining sector as it does about these two companies.
Capital-discipline mantras, ESG scrutiny and geopolitical sensitivity over critical minerals all conspired against a mega-merger that might have been cheered in an earlier supercycle.
The GlenTinto dream was real - but so were the barriers, and unless the miners develop more synergies with each other, a dream it will remain.
