Pension giant AustralianSuper, BHP Group’s largest Australian shareholder, said capital discipline was of “utmost importance” for the mining industry as investors weigh the heavyweight’s twice-rebuffed efforts to woo smaller rival Anglo American.

Luke Smith, the senior portfolio manager who oversees the fund’s Australian mining investments, declined to comment on whether or not it would support a takeover, but confirmed it had engaged “more than once” with BHP.

The world’s biggest miner approached Anglo last month with a proposal aimed squarely at the iron-to-diamond producer’s Latin American copper deposits — only to be swiftly turned down. It has since tabled a sweetened $43-billion all-share bid but maintained a structure that would see Anglo doing much of the heavy lifting on a restructuring before the deal goes through — including spinning off two listed South African businesses.

Anglo rejected the latest approach, arguing the non-binding offer continues to “significantly undervalue” the company and its future prospects, while creating “significant uncertainty” for shareholders. It has now laid out a bold self-help plan that would see it divest diamonds, platinum and coal.

“If part of your strategy is copper then you follow and try and execute on that strategy,” Smith said in an interview in Melbourne. But capital discipline is “of utmost importance, and I think that’s at the forefront of people’s minds when it comes to any consolidation across the commodity landscape,” he said.

BHP has long been clear on its desire to expand in copper, eager to take advantage of rising demand for a metal key for renewable energy installations, expanding grids and electric vehicles. But the mining industry is also emerging from more than a decade of purdah after a string of frenzied, ill-timed and overly expensive acquisitions that burnt billions of investor dollars and left even the largest firms saddled with debt.

“I think we are in a much stronger environment from a capital allocation aspect of the mining industry,” Smith said. “There probably wasn’t the focus then that there is now on capital allocation. And not just from the companies, but from the stakeholders.”

Anglo’s shares ended Monday slightly below the value of BHP’s offer, indicating the market is not yet convinced a deal will get done. Still, among the miner’s smaller Australian investors, many said they saw room for maneuver that could yet help BHP clinch its prey.

“Obviously they haven’t got there with a good enough offer yet, so watch this space,” said Matthew Haupt, portfolio manager at Wilson Asset Management in Sydney, who is underweight BHP. “Another 5% to 7.5% bump, with a cleaner structure, could get a deal done.”

Jun Bei Liu at Tribeca Investment Partners in Sydney, also a BHP shareholder, said an increase of another 15% could make the difference and that she expected BHP to try to get there. Any short-term dip in the price as a consequence would be an opportunity to increase exposure.

“They’re not buying for the next couple of years, they’re really looking into the future of the copper shortage,” she said. “Yes, there’s every chance of overpaying and mining companies haven’t had a great record on this, but what they’re saying is that they believe their strategy.”

The company was unlikely to take an openly hostile approach, though.

“It’s a big transaction, which requires a lot of regulatory approval across many jurisdictions. So I just think that being aggressive is going to be very costly,” she said. “There’s a lot more uncertainty with what is already a very complex deal.”