The automaker plans to increase production of the Sonata at the plant in Montgomery, Ala., said Hyundai Motor America spokesman Chris Hosford.
"We definitely wanted more production of Sonata at our plant in Alabama and the move allows us to do that," he said.
Hyundai Motor Co. and affiliate Kia Motors Corp. form the world's fifth-largest automotive group.
Hyundai's sales rose 6 percent last month from June and 19 percent from July 2009 on strong sales of sedans such as the Sonata. The company has said demand for the model has been so strong, it hasn't been able to keep up.
Its plan to increase production of the Sonata comes at a time when the automaker faces a potential Sonata recall.
The U.S. government launched an investigation into possible steering problems in the 2011 model involving roughly 16,300 cars.
Kia said production of the Santa Fe will begin next month at the plant in West Point, Ga., and ramp up on Oct. 1 with the addition of a second shift.
The plant will add roughly 700 employees, bringing the total to 1,900. Suppliers and other support companies in the area are also expected to add jobs.
Kia also builds its Sorrento SUV at the plant.
There will be no change in staffing at the Alabama plant.