The story
The company was founded on January 1, 1986, as the result of a merger between Ruteexpressen, Lillesand og Topdalens Bilruter, Torridalens Bilruter and Vaagsbygdruta and is owned by the holding company TK Brøvig that also owns Vaagsbygdruta and Sørlandsruta.
From Wikipedia’s article on Bussen Trafikkselskap, shared under CC BY-SA 4.0.3