Ford Motor Co., in an effort to better align its production capacity with demand, announces a series of plant shift reductions.

The auto maker’s assembly plants in Chicago and Louisville (KY) will operate on one shift beginning this summer, Ford says. A specific date has yet to be announced.

The Chicago plant builds the Ford Taurus and Mercury Sable sedans, as well as the Taurus X cross/utility vehicle. It employs about 2,300 workers and is slated to receive a new vehicle as outlined in Ford’s new 4-year labor agreement with the United Auto Workers union.

Louisville produces the Ford Explorer and Mercury Mountaineer SUVs and the Ford Sport Trac. The plant employs 2,200 workers and is slated to receive a new body shop and new product as part of the UAW pact.

Ford’s Cleveland Engine Plant No.2, which manufactures Ford’s Duratec 3.0L V-6 engine, will operate on one shift starting in late April.

Some 2,500 employees in total will be affected at the three plants.

Ford currently is offering its U.S. hourly workforce a series of buyout or early retirement packages. The window to accept the packages closes March 18.

Ford spokeswoman Anne Marie Gattari says the auto maker is informing employees now of the capacity reductions so they can weigh that into their decision whether to accept a buyout or early retirement.

“The buyouts and capacity actions are designed to ensure that our manufacturing facilities are operating in the most efficient way,” says Joe Hinrichs, Ford group vice president-global manufacturing.

“By adjusting our operating patterns in this way, we can produce the right volume and avoid down weeks. The stability in operations is better for our employees, our suppliers and the quality of the product.”

Ford says the switch to a 1-shift production pattern will not affect volume.

Meanwhile, Cleveland Engine Plant No.1, which has been idled since May 2007, will resume production in the fourth quarter. The plant assembles the Duratec 3.5L V-6 mill. Ford earlier said it would resume operations this spring.