BoB, there may be some theoretical advantage in doing so,...

BoB, there may be some theoretical advantage in doing so, however, most larger companies only get interested once there is more certainty and willing to pay more for that certainty. But if they were to start buying up the options, they wouldn't be able to keep it a secret (the word would get out pretty quickly) and that could have the effect of pushing up the share price significantly meaning a higher base price when they announce a takeover for the remaining 70% or so (assuming they had bought up all the options). Typically when a company buys up 20% of a company at the takeover threshold, their next move is going to either be to sell it off again if plans don't come to fruition or to commence a takeover for the remaining shares.