tullow have a problem, page-19

If a material change in HDR's situation takes place due to success in Mauritania or Uganda, then the basis of the offer has changed.
Tullow cannot execute a takeover at the bid price if insufficient shareholders want to sell at that price.
I firmly believe that the HDR sp was driven down in the weeks preceeding the offer as part of the strategy (and I generally scoff at conspiracy theories)
It is all up to the current shareholders.