"...The offer can?t be withdrawn, whatever Valeant thinks of it....

"...The offer can?t be withdrawn, whatever Valeant thinks of it. However, it does have a 90 per cent minimum acceptance condition. While that wasn?t expected to provide any obstacle to Cephalon?s success, it does offer Valeant a possible "out" .

Pearson told the analysts that he thought Valeant?s offer for Cephalon could be wrapped up, one way or another, in three or four weeks? time. It would be unusual if the Cephalon offer for ChemGenex attracted more than 90 per cent of ChemGenex?s capital within that timeframe. If it doesn?t, and Valeant were to gain control of Cephalon, it could refuse to extend the offer and let it lapse..."

http://www.businessspectator.com.au/bs.nsf/Article/Pharma-Pharmaceuticals-Cephalon-drugs-ChemGenex-pd20110401-FH4X7?OpenDocument