Mae Massilly UK, sydd wedi bod yng Nghymru ers 1984 ac sy’n gweithio o ystad Ddiwydiannol yr Hendy, Pontarddulais, yn is-gwmni sydd ym mherchenogaeth lwyr Massilly Holding SA, cwmni teuluol preifat sydd â'i bencadlys ym Mâcon, Ffrainc, ac sydd â 28 o is-gwmnïau yn Ewrop, yn ogystal ag yng Nghanada, De Affrica, Rwsia ac India.
Massilly UK, established in Wales since 1984 is based at Hendy Industrial Estate, Pontarddulais, is a wholly owned subsidiary of Massilly Holding SA, a private family company headquartered in Macon, France, which has 28 subsidiary companies in Europe as well as Canada, South Africa, Russia and India.