General Motors Corp. will close a stamping plant in Grand Rapids, MI, by the end of 2009, marking another manufacturing site slated to be shuttered due to weakened consumer demand for pickups and SUVs.

The Grand Rapids location devotes roughly 40.0% of its capacity to fullsize and midsize trucks. It employs about 1,340 hourly workers and 180 salaried personnel.

GM notifies workers at the plant on Michigan’s west side the same day it announces it will speed the closure of a fullsize SUV plant in Janesville, WI, from the end of 2010 to Dec. 23. Last month, GM said it would close a Moraine, OH, midsize SUV plant on Dec. 23, instead of the end of 2010.

GM also plans to close a large pickup facility in Oshawa, ON, Canada, and will cease medium-duty truck production in Toluca, Mexico, as part of its strategy to align production with a shift in consumer demand to more fuel-efficient vehicles.

GM wants to move its production mix from 50/50 cars and trucks to 60% cars in the next three years.

But as GM winds down its truck production at the assembly plants, it must also align capacity at associated stamping and powertrain facilities. Grand Rapids represents the first stamping site to close due to the rollback.

Light-duty truck sales through September are off 20.6% compared with the same period last year, according to Ward’s data, while deliveries of SUVs are down 36.1%.