WENTZVILLE, MOGM said it will invest $380 million in its Wentzville, Mo. assembly plant to prepare it for production of the new Chevrolet Colorado mid-size pickup truck. The automaker said this investment would create or retain 1,260 jobs in the U.S.

The Wentzville Assembly plant, which currently has about 1,400 employees, builds GM’s Chevrolet Express and GMC Savana full-size vans. In early October, the plant announced a second shift, which added about 400 employees, to meet customer demand for commercial vans. The second shift will start in January 2012.

The investments will support tooling and equipment upgrades. Product details, timing and pricing will be announced later. The current-generation Colorado will be produced in Shreveport, La., through the 2012 model year.