Some of the world's biggest private equity players are running the rule over BHP's shale assets, the sale of which now looks certain to trigger a giant shareholder return. 

Expectations are firming that BHP will return the proceeds of the sale, estimated at more than $US10 billion ($12.7 billion), straight back to shareholders, with analysts reporting that chief financial officer Peter Beaven declared last week that the cash raised "wouldn't touch the sides" as it went back to investors.

BHP revealed at its interim results announcement that data rooms on the company's assets in the Fayetteville shale have already opened, with data rooms for BHP's most attractive shale assets – including in the Permian and the Eagle Ford shales – expected to open within a month.

The resources giant had expected it might take up to two years to run the auction, but now it hopes the process may be completed by Christmas.

Chief executive Andrew Mackenzie said last Tuesday there had been strong interest in the assets both on an individual basis and as a complete package.

"We're very much marketing into what is a firming oil market," Mr Mackenzie said after the release of BHP's interim profit report.

"We could end up with several packages, or we may find a transaction where we sell the whole business, but we have strong interest at both ends of the spectrum."

Oil giants including Anadarko, EOG and Chevron are expected to look at some of the assets.

Last week, Royal Dutch Shell's upstream director Andy Brown told Bloomberg that BHP's Permian assets "may be interesting for us" given they "overlap our own acreage in the Permian".