Mondelez International warned local officials in Fair Lawn, N.J., and Atlanta that aging plants in those cities may close some time in 2021, although a final decision has not been made.

In New Jersey, Mondelez met with unios, employees and local officials to discuss the 62-year-old Fair Lawn plant, which makes Oreos, Chips Ahoy, Nilla Wafers and Ritz Crackers, according to local news website NJ.com. The factory’s closing would put 600 employees out of work.

Mondelez officials said both plants were outdated, that renovations would prove too costly and that the company can supply those regions from newer plants -- Richmond, Va., for the East Coast and Chicago and Naperville, Ill., for the central part of the country. Mondelez also uses a network of contract manufacturers.