The Montupet company, which is based in Dunmurry and which employs 600 people, has been taken over by family-run Canadian firm Linamar in a deal which is estimated to be worth £629m.
Montupet has operated in Northern Ireland since 1989 and is based at the former home of the famous car maker DeLorean.
The firm manufactures cast aluminium cylinder heads for petrol diesel engines used for car makers Ford, Peugeot, Citroen, Volvo, Fiat and Mazda.
Montupet’s Dunmurry plant sends its products to engine plants in the UK, France, South Africa and China amongst many other countries.
Last year the company announced a new £140m contract for the Dunmurry plant.
Linamar, based in Guelph in Ontario, is made up of 37 manufacturing plants around the world, employing 23,000 people in total.