Buyout firm Catalyst Capital Group Inc said it will acquire a significant stake in Hudson's Bay Co, a move that could block the department store's executive chairman's plans to take it private for C$1.74 billion.

Catalyst's acquisition, which it plans to finalize within days, represents the most significant move yet that could prevent Hudson's Bay executive chairman Richard Baker from taking the company private with a consortium of shareholders holding 57 percent of the company. Baker needs a majority of minority shareholders to approve any deal he offers for the owner of department stores Saks Fifth Avenue, Lord & Taylor and Hudson's Bay.