BHP offer required 51% not including the 3% or so that already held.  There was no such requirement in the as yet not approved/accepted offer by Wyloo.  They would need 51% which would include the 37% or so they already hold....so 13 -14% if a simple majority is the threshold.  If Noront acepts an offer by Wyloo as a better offer than BHP then would suspect the BOD would allot their combined 9% or so to the offer making it 46% or so.  Would also expect if the option of share continuation in the "New Noront" remained they'd have little trouble get the remaining 4% or so.

Have seen times where the selling/takeover company had prior provisions in their company constitution9sometimes for a hostile takeover) where more than a simple majority is needed such as 2/3rds or 75% but seems, seeing as they accepted BHP at 51%, it doesn't appear there are any such provisions here.