General Motors ( GM) said it has scheduled shutdowns at 13 of its 21 assembly plants in North America, removing 190,000 vehicles from production. In the peak weeks of the shutdown, in the early part of June, about 40% of GM's production capacity will be idled. Shutdowns begin the week of May 11 and continue through the week of July 13. Some plants will be closed for as long as eight weeks. The move will enable GM to reduce inventories to 525,000 vehicles from the current level of 767,000; bring production in line with market demand and accommodate potential outcomes of talks with bankrupt Delphi and its lenders, who recently rejected GM's settlement proposal. "What we're really trying to do is protect ourselves from a disruption that could occur in this period of time, and we also have this inventory to take down, so maybe we can kill two birds with one stone," said Troy Clarke, GM North American president, on a conference call with reporters. "We've been working with Delphi for almost four years," he said. "We have been in very serious negotiations with Delphi and its lenders ... to assure our supply of parts. We made a very serious and fair offer that seemed to be very workable and the offer was rejected." Some of the plants build slow-selling vehicles, including the Cadillac STS sedan and the full size Chevrolet Suburban SUV. GM said it will not shut down plants engaged in products like the Chevrolet Camaro and the Buick LaCrosse. Additionally, Clarke said no shutdown is planned for the Orion Township, Mich., plant where the Chevrolet Malibu is made. "The Malibu is in short supply," he said.