General Motors has said it would speed up production cuts at a pickup truck factory in Flint, Michigan, that had been closed due to a strike at a parts supply company.

Spokesman Tony Sapienza told the Associated Press (AP) it was unclear when the Flint plant would restart production and, when it did, GM would cut the third shift due to slow sales of the Chevrolet Silverado and GMC Sierra models.

AP noted that the company announced last month it would cut the third shift at Flint from 14 July.

Affected GM plants are slowly returning to work after both an almost-three-months strike at American Axle and Manufacturing, that caused a parts shortage that crippled GM production of pickups and large SUVs, and specific facility disputes with local United Auto Workers union branches over issues not settled in last year’s national agreement.

GM also announced in April that it would cut shifts at a Pontiac, Michigan, pickup truck plant and a Janesville, Wisconsin, SUV factory in July, the Associated Press added.