General Motors is closing four truck and SUV plants in the US, Canada and Mexico as surging fuel prices hasten a dramatic shift to smaller vehicles. CEO Rick Wagoner said Tuesday before the automaker's annual meeting in Delaware the plants to be closed are in Oshawa, Ontario, in Canada; Moraine, Ohio; Janesville, Wisconsin; and Toluca, Mexico. He also said the iconic Hummer brand may be discontinued. Wagoner said the GM board has approved production of a new small Chevrolet car at a plant in Lordstown, Ohio, in mid-2010 and the Chevy 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 says a market shift to smaller vehicles is permanent. The cuts will affect about 2,500 workers at each of the four facilities, although Wagoner did not know exact numbers. Many will be able to take openings created when 19,000 more hourly workers leave later this year through early retirement and buyout offers. He said the company has no plans to allocate products to the four plants in the future. GM plans to cease production at the four factories and has no plans to allocate future products to them, Wagoner said. “We really would not foresee the likely prospect of new products in the plants that we're announcing today that we'll cease production in,” he told a Moraine, Ohio, city official who asked a question in a telephone conference call. The moves will save the company $1 billion per year starting in 2010.