As far as i know, nothing can stop a major from buying the 25% on SC and CF is, as far as i know, free to sell their 25%. So, it might be interesting, if they have the patience and money, to buy or only the 25% of SC or the 100% of CF. CF will like this, but Teck won't like it, cause they rather choose their own partner. So, in my opinion, finding a major who might be interested in the 25% or the 100% of CF will put pressure on Teck and so interesting for the negotiations.
Teck has Right of First Refusal - so until copper fox excercises this - I don't think we can't just sell to anyone - we have to put the $$$$'s on SC - Teck will then have to decide if they will bite....if not, then we can go to market.....i think this is how it works!