French steelworkers in two northern French cities have begun a strike, the CFDT union told Reuters on Wednesday, following ArcelorMittal's (NYSE:MT) warning of two potential plant closures that would affect 130 workers.

The steelmaker said the closures could happen because of problems in the European auto industry as well as high raw material and energy costs.

With Europe's industrial economy continuing to struggle, ArcelorMittal's (MT) announcement comes two weeks after French tire maker Michelin said it was closing two French sites.

Separately, ArcelorMittal (MT) said it started operations at a new steel galvanizing and continuous annealing line at its Vega unit in São Francisco do Sul, in Brazil's Santa Catarina state.

The company has spent 2B reais (~$345M) to increase installed capacity at the CMC project to 2.2M metric tons/year from 1.6M tons/year.