NEW YORK (Reuters) - Teva Pharmaceutical Industries Ltd <TEVA.TA> <TEVA.O> plans to acquire specialty drugmaker Cephalon <CEPH.O> for $81.50 a share, topping an unsolicited bid by Canada's Valeant Pharmaceuticals International Inc <VRX.TO>.

Teva said the deal was worth about $6.8 billion on an enterprise basis. The deal is worth about $6.2 billion, based on the number of Cephalon shares outstanding, according to Thomson Reuters data.

(Reporting by Lewis Krauskopf; Editing by Lisa Von Ahn)