DETROIT — DaimlerChrysler AG's Chrysler Group plans to build two new plants in Michigan and upgrade three others, but because the plants will be more efficient, there will be a net loss of about 1,400 jobs.

The $1.78 billion investment, formally announced Wednesday, includes a new $700 million axle plant in Marysville near Port Huron and a new $730 million plant in Trenton to build the next generation Chrysler V-6 engine.

The company also plans to build a new $300 million paint shop at its plant in Sterling Heights, where it makes the Chrysler Sebring and Dodge Avenger mid-sized cars, and it also is making a $50 million investment in its Warren stamping and assembly complex, which now makes the Dodge Ram and Dakota pickup trucks. A new version of the Ram is coming in 2008, the company has said.

The new axle plant will replace the Detroit Axle plant, which was built in 1917 and now employs more than 1,600, and the engine plant will replace the current engine plant in Trenton, which also employs about 1,600 people.

The new Marysville plant will employ about 900 workers, while the new engine plant would employ about 485, the company said. The net job loss is about 1,465 because about 350 workers at the existing Trenton and Detroit Axle plants are expected to take buyouts or early retirement offers under a restructuring plan announced Feb. 14. The company hopes to shed 13,000 jobs under the restructuring plan.