The strategic review follows talks with large shareholders, who concluded that "now is not the right time to commence an outright sale of the company," SunOpta said in a statement.

Hedge fund Tourbillon, which holds a 9.9 percent stake in SunOpta, said in May that it was going public with its request for a sale of the company after months of private talks.

Tourbillon said then that it might push for changes to SunOpta's board and management if business did not pick up.

"SunOpta continues to transition into a consumer packaged goods company. The plan is on point in our view, however we await execution, which remains the clear obstacle for financial success," D.A. Davidson analyst Eric Gottlieb wrote in a note.

The brokerage reiterated its "buy" rating and $6 price target, calling the stock "well undervalued".

SunOpta, which specializes in sourcing, processing and packaging of organic food products, said on Monday that it hired Rothschild Inc as its financial adviser and Davies Ward Phillips & Vineberg LLP as legal adviser.

The Toronto-based company has also hired Russell Reynolds Associates to help identify director candidates, including those suggested by shareholders.

A spokeswoman for Tourbillon declined to comment.

SunOpta's U.S.-listed stock was down 5.2 percent at $3.95 in early afternoon trading, reversing premarket gains. Its Toronto-listed stock was down 4.2 percent at C$5.21.

(Reporting by Arathy S Nair in Bengaluru; Editing by Kirti Pandey and Saumyadeb Chakrabarty)