Both point to transportation projects that could have secured work for the Thunder Bay plant.
Local Unifor president fears more job losses beyond the initial layoffs as the contracts wind down.
The agreement in question dates to 1906.
Agreement includes wage increases for production and skilled trades workers, pension increases and a fold in cost of living allowance.
The manufacturer and Unifor have failed to reach an agreement on pension changes and benefit reductions.
Will create 24 jobs to turn residual materials into a source of renewable energy.