The two sides in a dispute that shut down production at a Windsor auto parts supplier last month are meeting with an arbitrator.
Nemak and Unifor hope to reach an agreement on the closure of the company's plant in Windsor planned for mid-2020.
Talks between the union and the company earlier this month broke off on the second day of three days of negotiations.
Unifor Local 200 argues the company broke its collective bargaining agreement when it announced the closure of the facility earlier this year. It said the workers had agreed to a wage freeze if the plant stayed open until 2022.
It also pointed out the company accepted $4.5 million in government funding to stay operational in Windsor.
Unifor National President Jerry Dias kicked off a blockade at the plant on Labour Day, which lasted for 16 days.
A ruling from the Ontario Labour Relations Board and a Windsor judge ordered the union to allow production to resume, but it refused until the company committed to talks with Unifor. Part of that agreement was also a promise to submit to arbitration should those talks fail.
Nemak currently employs about 200 workers, and the facility in Windsor produces 2.0-litre aluminum engine blocks for General Motors. The company plans to move production to Mexico next year.