As a bidder, BHP, can not accumulate shares outside of the tender process.  That said, organizations that may be friendly or seek to be friendly to the BHP can as long as it is not an arrangement of any sorts (e.g. it needs to be a trues arms length deal).

I personally don't think that BHP has made any progress with shareholders in advancing to control.   They seem to be more interested in tweaking 'Twiggy's' nose then enticing me to tender.

BHP currently own ~3.7% of outstanding shares and has a lockup agreement with the NOT BOD/Execs for another ~9.9% of the outstanding shares (as long as BHP's offer is considered superior.

Wyloo currently owns ~37.3% of the outstanding shares.

The wild card for me is BaoWu (e.g Baosteel) who holds 4.9%.   I'm not sure if they are still considered an insider by virtue of their original agreement with NOT. If they are not I assume they can accumulate up to 10% before disclosing their holding.   That would certainly put them in a position to be a 'King of the Ring' maker in this bidding war.

Similarly I wouldn't put it past Franco Nevada to have a holding that they would use to extract a promise of timely development of the chromite deposit so they get their royalties sooner.

We will never know all the inside deals that are out there but this will start to get really interesting as the players are exposed.

... Been There