The shutdowns are due to declining consumer demand for the truck-based vehicles amid rising gas prices.

The company and the United Auto Workers union local said GM plans to shut the Shreveport plant down the week of July 14, on top of the regular shutdown for vacations the first two weeks of the month. GM did not say whether there will be additional shutdowns the rest of the year.

The west Shreveport plant makes mid-size pickups for Chevrolet and GMC and the Hummer H3 SUV.

GM spokesman Chris Lee said the company will cut shifts, reduce assembly line speeds and temporarily idle the seven factories in the United States, Mexico and Canada.

Employees in Shreveport will get most of their salaries through a union fund while they are idled.

The biggest cut will take place at the company's Janesville, Wis., factory that makes large SUVs. It will be idled the weeks of July 14 and 21 and be shut down another 10 weeks through the end of the year.

Lee said the other affected plants are in Arlington, Texas; Ontario, Canada; Silao, Mexico; Moraine, Ohio; and Fort Wayne, Ind.

The Associated Press contributed to this report