Rockwool International A/S is a Danish industrial group and the world's leading manufacturer of stone wool and insulation products. It was founded in 1909 by Valdemar Kähler and H. J. Henriksen, as a quarry near Korsør, and in 1937 began production of the insulation product stone wool in Denmark and Sweden under the name Rockwool.

The group grew strongly from the 1950s by establishing and taking over factories in other European countries, and from the late 1980s also outside Europe (Canada and Malaysia). Rockwool now has over 45 factories in 39 countries and is the world's largest stone wool producer.

In 2020, the group had a turnover of approximately 2.6 billion euros and around 11,000 employees. The largest owners in the group are the Rockwool Foundation and the Kähler family.

Rockwool in Norway
In Norway, A/S Rockwool has its head office in Oslo and factories in Trondheim and Moss. The first Norwegian factory opened in Larvik in 1938. It was closed in 2002. Rockwool's Norwegian operations were in the period 1965–1992 a collaboration with Elkem (Elkem-Rockwool).

Source: https://snl.no/Rockwool_International