The seller is the Canada Pension Plan Investment Board, which will continue to own 50 per cent of the shopping centre.
The mall has The Bay, Sears and Toys R Us among its retailers — with Target on its way this fall.
Financial terms weren't disclosed in the announcement Monday.
Ivanhoe Cambridge, which will manage the mall on behalf of both owners, is the real estate arm of Quebec's Caisse de depot pension system.
Ivanhoe Cambridge executive Claude Sirois said the acquisition is aligned with the Montreal-based company's plan to invest in strategic assets in Quebec.
"We look forward to building on this relationship with CPPIB and working together on other projects of mutual interest," said Sirois, who is co-chief operating officer and senior vice-president of Ivanhoe Cambridge