MONTREAL -- Bill Ackman's Pershing Square Capital Management has increased its stake in embattled drugmaker Valeant Pharmaceuticals International Inc.
The investment manager disclosed in its latest regulatory filings that it now has a 9.9 per cent in the Canadian company.
Pershing Square Capital first announced its investment in Valeant in March when it bought a 4.9 per cent stake.
Shares in Valeant have been under pressure in recent weeks after being hit by U.S. investigations into its drug-pricing policy and a report from short-seller Citron Research that opened up the company to questions about some of its business.
Ackman has been a vocal defender of its investment in Valeant and the company's chief executive, Mike Pearson.
Shares in Valeant are down more than 60 per cent from its highs of earlier this year.
