Newmont Mining , the world’s largest gold producer, may be preparing a sweetened takeover offer for Newcrest Mining which rejected the miner’s unsolicited bid six weeks ago.

Speculation on a potential deal, originally estimated at $17 billion, comes as Newmont reportedly gained partial access to its Australian rival’s corporate books.

Anonymous sources who spoke to Bloomberg News on Wednesday said the fact that Newmont was undertaking limited due diligence on Newcrest signed that the US company could make a revised offer to seal a takeover deal.

While initial feedback from analysts and shareholders suggested that Newmont will have to improve its bid, experts now see few options for Newcrest, with no obvious alternative buyers to challenge Newmont’s.

Barrick Gold, the world’s no. 2 bullion producer, has said it doesn’t plan to make a rival offer and Agnico Eagle Mines, the third-largest gold miner, is busy wrapping up a deal with Pan American Silver to jointly acquire Yamana Gold.

If successful, the Newmont-Newcrest tie-up would be one of the biggest in Australian history, as the target company is the country’s no.1 gold producer.

It would also increase Newmont’s footprint in high-demanded copper, as prices have soared recently due to its use in renewable energy and electric vehicles.

Agreeing on a price tag that satisfies both sides could stretch negotiations over several weeks or months, Sprott Asset Management’s Douglas Groh told Bloomberg News on Wednesday.

“I think a deal is inevitable,” Groh said, adding it’s obvious to the market there’ is a lack of leadership at Newcrest. The company’s chief executive officer surprised investors in December by abruptly leaving the post.

Newcrest currently operates the large open-pit and underground Telfer mine in Western Australia’s Pilbara region and is the top gold producer in British Columbia, Canada since the 2019 acquisition of the Red Chris copper and gold mine.

Last year, the company expanded its footprint in Canada with the takeover of Pretium Resources, which handed it the Brucejack gold mine.

The company also operates the Lihir and Hidden Valley mines in Papua New Guinea.

Newmont did not respond to requests for comments on the issue.