The company and Illinois Gov. Pat Quinn are scheduled to make the announcement on Tuesday at the factory, but Quinn told reporters in Chicago on Monday that 1,200 new jobs were coming to Illinois.
"Tomorrow, in one day, we're going to get 1,200 new jobs for Illinois," Quinn said at a breakfast event that was unrelated to the Ford announcement.
The person briefed on the announcement said some of the workers will be from Ford's pool of employees laid off at other factories. The person did not want to be identified because the announcement has not been made.
The new Explorer will be built on the same frame as the Taurus sedan, which is built at the Chicago plant.
Ford has long had plans to base the once-popular Explorer on a car rather than truck frame. The company says the new one will have SUV-like towing and hauling capacity, but will be more maneuverable and fuel efficient than its predecessor.
Ford has sold more than 6.5 million Explorers since the SUV went on sale in 1990 as a 1991 model. But the segment has been suffering due to high gasoline prices. Ford sold only 52,190 of the truck-based Explorers last year, down 34 percent from 2008.
By AP Auto Writer Tom Krisher; AP Writer Deanna Bellandi in Chicago contributed to this report