if you look at conditions for the acquisition of Hanson, they...

if you look at conditions for the acquisition of Hanson, they put up an absolute $ sum in shares of Blr no matter what the shareprice is. So current holders gets seriously diluted if the deal is going through with a low VWAP based shareprice. Given the fact that the deal is about to close, a significant higher shareprice is in th e interest of all current holders. So i expect current (large) holders are behind the buying in order to minimize their dilution.

Enjoy,
Pisa_