G.M. will idle more factories this month as a chip shortage drags on.

General Motors said on Thursday that it would idle six North American plants for two weeks this month and two others for a week each as the global shortage of computer chips continues to stymie carmakers.

Four plants in the United States will be affected — Fort Wayne, Ind.; Wentzville, Mo.; Spring Hill, Tenn.; and Lansing Mich. — as well as three in Mexico and one in Canada. The company is suspending production of some of its most profitable vehicles, including its full-size and midsize pickup trucks and sport-utility vehicles.

“These most recent scheduling adjustments are being driven by the continued parts shortages caused by semiconductor supply constraints from international markets experiencing Covid-19-related restrictions,” G.M. said in a statement.

The move is the latest sign that the shortage of parts is lingering longer than most automakers had expected. Several had forecast that the tight supply of semiconductors would begin to ease in the second half of 2021. Both G.M. and Ford Motor recently lifted their forecasts for operating profit this year, in part because the tight supply of vehicles has allowed dealers to sell cars for higher prices.

But on Wednesday, Ford reported that its new-vehicle sales declined by a third in August, to about 124,000 cars and light trucks, compared with the same month a year ago. Hyundai reported a sales decline of 16 percent and Toyota Motor of 2 percent.

Some factories in Asian countries like Malaysia that supply the auto industry have had to slow or stop production because of a rise in infections from the Delta variant of the coronavirus, according to auto executives and analysts.

Ford is idling production of pickup trucks at a plant near Kansas City, Mo., next week, and will slow production of heavy-duty pickups at a Kentucky plant for the next two weeks. Toyota is cutting production 40 percent worldwide this month because of the chip shortage.

And Tesla’s chief executive, Elon Musk, on Wednesday blamed supply chain problems for not being able to start selling a new version of its Roadster sports car until 2023. The electric carmaker previously delayed the production of a pickup truck and a semi truck.