Chrysler LLC announced Thursday it will invest nearly a quarter of a billion dollars and add approximately 1,250 jobs at three of its plants in Michigan.

Fiat-Chrysler CEO Sergio Marchionne made the announcement at the Mack I Engine Plant in Detroit.

The company will invest a total of $238 million in the plants. Of that, $198 million will be spent at the Mack plant, where the company’s 4.7-litre V-8 engine is currently made. A new production line will be added there to make the 3.6-litre Pentastar V-6 engine.

A third shift will be added at its factory in Warren, Mich., where the Dodge Ram 1500 is built.

Chrysler will also invest $40 million in its Trenton Engine Plant, where production of its Pentastar V-6 engine and four-cylinder Tigershark motor will increase.

"Today is another important milestone in living up to the commitment we made more than three and a half years ago to our employees, this city, this region and our country to transform this company," said Marchionne. "All of these investments are the direct result of a lot of people who have battled courageously to bring Chrysler back to a state of growth. It is our contribution toward helping southeastern Michigan get back on its feet."

According to Chrysler, the recent announcement increased the company's investment in U.S. plants to nearly $4.75 billion since June 2009. In the same time frame, the company has added nearly 6,000 hourly jobs.

"These new investments and new jobs are a testament to the determination we all had – management, labor and our workforce – to making the best of the second chance we were given in 2009," said General Holiefield, Vice President and Director of the UAW Chrysler Department. "In partnership with the UAW, Chrysler Group is helping grow good paying manufacturing jobs and securing the future manufacturing base in this country."