CEO Rick Wagoner said Tuesday before the automaker’s annual meeting in Delaware the plants to be idled are in Oshawa, Ontario; Moraine, Ohio; Janesville, Wis.; and Toluca, Mexico. He also said the iconic Hummer brand will be reviewed and potentially sold or revamped.

Wagoner said the GM board has approved production of a new small Chevrolet car at a plant in Lordstown, Ohio, in mid-2010 and production of the Chevrolet Volt electric vehicle in Detroit.

Wagoner announced the moves in response to slumping sales of pickups and SUVs brought on by high oil prices. He said a market shift to smaller vehicles is permanent.