PERTH - Shares of BHP Group touched a three-month high on Tuesday about 36 hours ahead of a deadline to lodge a formal bid for rival miner Anglo American, which last week rejected a sweetened $43-billion takeover proposal.

The world's largest listed miner's shares are benefiting from good news including fresh stimulus for China's property sector, copper prices reaching record highs and a growing view that BHP will not make another tilt at Anglo, according to Andy Forster, senior investment officer at Argo Investments, a BHP shareholder.

"We saw last week that they had a bit of a bounce after rejection by Anglo," he said. "I think they're going to stay disciplined. I'd be surprised if they'd come back at this late stage given the lukewarm response from Anglo's board to the previous offers."

Under UK takeover rules, BHP has until 16:00 GMT on Wednesday to make a binding bid for Anglo American or it will be forced to walk away for at least six months. If the companies reach an agreement in the meantime, an extension can be granted.

BHP declined to comment on Tuesday. Its shares were up 0.5% to A$45.93 in afternoon trading. Anglo's London-listed shares closed 0.1% higher at 26.80 pounds on Monday.

Anglo's board has already knocked back two all-share proposals from BHP as inadequate and too difficult to execute and last week unveiled plans for a break-up to focus on energy transition metal copper while spinning out or selling its coal, nickel, diamond and platinum businesses.

The copper assets make strategic sense for BHP but the longer the deal takes to close, the more likely it is a competitor lobs a rival bid for some of Anglo's assets, according to Hayden Bairstow, an analyst at Australian stockbroker Argonaut.

"The risk of waiting is that Anglo's metallurgical coal assets go to someone else or an interloper like Glencore comes in with a more compelling deal," he said.

It would take Anglo a minimum of six to 12 months to run a sales process for the coal assets, according to an Australia-based investment banker who spoke on condition of anonymity.

Bankers are now jostling to get business from potential buyers, the person added.

Jefferies analysts said last week that BHP could be interested in the coal assets if it did not succeed in its bid for Anglo, given it owns nearby mines.

BHP would need to boost its latest offer by about 30% to reflect fair value for Anglo and its key copper assets, JPMorgan analysts said in a note last week.

Both of BHP's offers required Anglo divest its platinum and iron ore assets in South Africa, where it employs more than 40 000 people.

BHP has told investors it will not drop its requirement for Anglo to demerge those businesses as a condition of the deal.