Complex sentence: Follum Fabrikker (founded as Follum træsliberi in 1873), was started at Follum in 1873 and operated as a separate company until it was purchased in 1989 by Norske Skog Follum.
Split into simpler sentences: Follum Fabrikker (founded as Follum træsliberi in 1873), was started at Follum in 1873. It was purchased in 1989 by Norske Skog and now operates as Norske Skog Follum.