The Quebec-based company Sico is going to shut down a factory in Beauport and close a distribution centre in the Montreal area.
Production will be moved to a facility in Ontario.
Parent company PPG said the closures are planned for September 2019, and will affect 125 employees.
Sico's administrative offices are in Longueuil, and the company promised to maintain "a strong presence in Quebec and in Canada."
Union officials said the move took them by surprise and they hope the provincial government will intervene.
They pointed out that Premier Francois Legault was on the board of directors of Sico at one point.
On Thursday Legault said that he was annoyed by the move and said Quebecers should boycott the company if it stops producing paint in the province.
Sico was founded in Quebec City in 1937, and was purchased by AkzoNobel in 2006, which was acquired by PPG Architectural Coatings in 2013.
