MONTREAL -- Valeant Pharmaceuticals is weeks away from hiring a new CEO to oversee the embattled drugmaker's turnaround, one of the company's largest investors said Wednesday.

Bill Ackman of Pershing Square Capital Management, who also recently joined the Quebec-based company's board of directors, said there are a number of candidates for the top job under consideration.

"The best time to be CEO is when expectations are extremely low and the starting valuation is extremely low," he said in a conference call from London after Pershing Square reported its first-quarter results.

"And Valeant certainly offers that."

Late last month, the company announced Michael Pearson was leaving as CEO after eight years.

Once one of Canada's most valuable companies following years of acquisitions, Valeant (TSX:VRX) has seen its shares plunge amid controversies over drug prices and its relationship with U.S. mail-order pharmacy Philidor.

Ackman said Valeant can regain investor confidence by releasing revised financial statements, as it plans to do, later this month, as well as adding new management and delivering several quarters of good results.

Valeant's shares surged by 18.5 per cent Wednesday, closing at C$44.77 on the Toronto Stock Exchange. That's still down from its peak closing stock price of $346.32 per share set in August.