In a bid to salvage profitability from its high-profile minivan lineup, Chrysler LLC says it will idle its minivan plant in St. Louis indefinitely beginning Oct. 31.

The auto maker also will reduce production at its St. Louis pickup plant by one shift.

The moves come in response to a “turbulent” sales climate marked by a major market shift, says Co-President and Vice Chairman Tom LaSorda.

Stunned by rising gasoline prices, consumers are abandoning light trucks in favor of more fuel-efficient cars.

Chrysler’s minivans have been hit particularly hard. Through May, they accounted for 16.0% of the auto maker’s overall sales – a 1.3-point decline compared with the same period of 2007, according to Ward’s data.

Deliveries of the auto maker’s Dodge-brand minivan plummeted 34.6% through the first five months of this year vs. like-2007. Meanwhile, sales of the upscale Chrysler Town & Country fell 13.4%.

The actions are part of a sweeping measure to reconcile Chrysler’s assembly capacity with a market that has seen the auto maker’s overall sales decline 19.6%.

Chrysler will continue to build minivans at its remaining assembly site in Windsor, ON, Canada, the plant that introduced the segment-defining vehicle in 1983.

Chrysler redesigned its minivans for ’08, opting for a boxier exterior and more sumptuous and functional interior. They were launched to much fanfare, but have fallen victim to volatile gasoline prices.

Chrysler’s St. Louis operation benefited from a $500 million investment designed to enable it to build multiple models from multiple platforms.