Chrysler plans on adding 1,600 production workers to an Illinois assembly plant, the first step in a rejuvenation the company expects will add thousands of workers to its payroll over the next three years.

Sergio Marchionne, CEO of Chrysler's parent company Fiat, will announce the addition on Thursday, at the car maker's plant in Belvidere, Ill.

Beginning in July, the new employees will start making Dodge Darts, Jeep Compasses and Patriots, according to The Wall Street Journal.

The company has enjoyed a resurgence since it joined Fiat. Sales from the Chrysler family of vehicles jumped 37 percent in the fourth quarter, to 137,271. The brand saw a renaissance in 2011, with sales increasing 26 percent to 1.37 million vehicles, largely driven by demand for its Jeep line of sport utility vehicles.

The company has increased productivity at its plants by instituting a new shift structure for employees, eventually introducing a 3-2-120 system where three crews on two shifts work 120 hours.

We have to put in more than one shift in a variety of plants, Marchionne said in a Wall Street Journal interview last year. If we're going to move up to producing 2.4 million cars I need to make them somewhere. I mean I can't do it with the existing shift pattern. It's not as if I'm turning on more plants. I don't have any.