Oct 20 (Reuters) - Valeant Pharmaceuticals Inc may raise its hostile takeover bid for Allergan Inc and will not walk away from its pursuit ahead of Allergan's Dec. 18 special shareholder meeting, Chief Executive Michael Pearson said on Monday.

Pearson also said speculation that Valeant's relationship was strained with Pershing Square Capital Management, Allergan's biggest shareholder, is false.

(Reporting by Rod Nickel in Winnipeg, Manitoba Editing by W Simon)