Activist Pershing Square starts process to change Allergan board

June 2 Mon Jun 2, 2014 8:48am EDT

June 2 (Reuters) - Activist investor Pershing Square on Monday said it launched a process to call a special meeting of Allergan Inc shareholders, a move that could turn over most of the drug company's board and open the door to a takeover by Valeant Pharmaceuticals Inc.

Pershing CEO Bill Ackman, whose hedge fund owns 9.7 percent of Allergan, urged the company to negotiate with Valeant and said a merger deal could be done within a week. (Reporting by Rod Nickel in Winnipeg, Manitoba, Editing by Franklin Paul)