May 19 (Reuters) - Activist investor William Ackman said on Monday in a letter to takeover target Allergan Inc's board of directors that the top executive has a "disabling" conflict of interest because accepting a takeover means losing the top job.
Ackman and Valeant Pharmaceuticals International launched a $47 billion takeover of the company on April 22 but so far Allergan has rejected its advances and Chief Executive Officer, David Pyott is pushing shareholders to let the company stand alone.
Allergen is the maker of Botox.
Ackman owns nearly a 10 percent stake in Allergan. The May 19 letter from Pershing Square Capital Management head was disclosed in a regulatory filing with the Securities and Exchange Commission. It is the latest in a series of public tactics Ackman has used to try to gain shareholder support for the deal. (Reporting by Caroline Humer; Editing by Sofina Mirza-Reid)