TORONTO — Mondelez Canada, a division of Mondelez International, is planning to close its Mr. Christie cookie plant in Toronto in the third quarter of 2013. The closing will affect about 550 employees.

The 625,000-square-foot plant was built in 1948. Mondelez said the decision to close the plant was due to facility’s age and the surrounding area.

“This is a difficult decision, given the role this facility has played within our organization and in the community for 64 years,” said Alvaro Cuba, vice-president of operations for Mondelez Canada. “However, the plant faces some unique challenges resulting from the changing neighborhood surrounding the facility.”

Mr. Cuba said while it was an appropriate location for a large bakery when it was first built, the significant residential development surrounding it has led to operating constraints that will become increasingly difficult with the further residential expansion that is under way.

Mondelez said some of the current production at the bakery will be transitioned to other bakeries in Montreal and Toronto, and the rest will be split between the company’s other North American plants and co-manufacturers.