Rockwell: The Seal Beach company said Tuesday...

Rockwell: The Seal Beach company said Tuesday that it has completed the sale of its automotive plastics business to Cambridge Industries Inc. of Dearborn, Mich. Terms of the transaction were not disclosed.

The sale of Rockwell’s plastics business, announced in May, includes three manufacturing plants in Centralia, Ill., and Lenoir and Newton, N.C. The plastics business has about 1,700 employees, 20 of whom are sales and engineering personnel working in the Troy, Mich., headquarters of Rockwell Automotive.

Cambridge said it will have annual revenue of about $300 million with the addition of Rockwell’s automotive plastics business.