Allergan Adopts ‘Poison Pill’ to Defend Against Possibility of Hostile Takeover by Valeant


IRVINE, Calif.— Allergan, Inc. (NYSE: AGN) is using a “poison pill” defense tactic to rebuff a possible hostile takeover by Canadian company Valeant Pharmaceuticals International Inc. (NYSE/TSX: VRX) and activist investor Bill Ackman.

On Tuesday, Allergan announced the move in the form of a one-year “stockholder rights plan.” The plan enables existing shareholders to buy Allergan stock at a significant discount if any single investor acquires more than 10 percent of its Allergan's common stock.

Earlier this week, Ackerman revealed that his company, Pershing Square, had acquired 9.7 percent of Allergan’s shares. The poison pill prevents Ackman from significantly increasing Pershing’s holding.