Linjeflyg was formed in 1957 as a Swedish domestic airline.
In 1983, Linjeflyg moved from Stockholm-Bromma Airport to Stockholm-Arlanda Airport. In 1992, Linjeflyg became too big a threat for SAS as they planned a strategic alliance with Braathens and Maersk Air. The alliance would have been to competitive on the intra-Scandinavian capital routes and on the domestic networks. Consequently, SAS bought up the last 50% in Linjeflyg. On 1 January 1993, Linjeflyg was merged into SAS.
Source: Wikipedia
