if they sold the principal assets of PRT they would need to put...

if they sold the principal assets of PRT they would need to put that to s/h.
at last AGM only about 200m shares voted.
PRT has about 366m shares.
So if BG has control of about 20%, then he controls the votes of about 73m shares.
if only 200m shares vote on a disposal of assets, then BG would have 36.5% - plenty to block sales -> kingmaker.
if 250m vote, BG would have 29% -> still kingmaker.
if 300m shares vote, BG still has 24% -> still kingmaker.
It is not possible in practical terms, to do a deal which requires a 75% s/h approval, without the agreement of BG, if he is allowed to vote. It just won't happen. Of course a scenario could arise where BG interests are not allowed to vote - that is a real possibility.
BG moved to 20% because he wants to be in a position to control what happens to PRT in a M&A environment.
I have no idea what he wants.
I have no idea where all this will go. But we can be sure that there is more to play.
cheers