Mazda CX-5

Mazda CX-5

Irvine-based Mazda Motor of America Inc. said it planned to open a $1.6 billion manufacturing facility in Huntsville, Ala., in a joint-venture with Toyota Motor Corp.

It said the plant is expected to open in 2021, employ 4,000 workers, build 300,000 vehicles a year, and boost Mazda’s U.S. sales.

Production will be split equally between Mazda’s CX cross-over models and the Toyota Corolla, and boost Mazda’s U.S. sales.

Mazda’s 2017 U.S. sales declined 7.8% year-over-year to about 289,500 units.