CNBC reported that a total of some 3,725 GM staffers have been temporarily laid off, plus another 2,000 workers at suppliers.
About 525 hourly employees at the auto maker's DMax engine facility in Ohio and about 700 at the St. Catharines, Ontario, power-train plant are affected by the latest move, company and union officials told the news service.
On Sept. 16 some 48,000 workers took to the picket lines at 33 plants and 22 warehouses.
The nationwide strike action, the first in more than a decade, followed failed talks between GM and United Auto Workers officials over a new four-year contract.
Key issues include profit sharing, healthcare benefits and plant closures under CEO Mary Barra.