The origin of the grouping was the operators owned by and including the Scottish Motor Traction company, which were transferred to Scottish Omnibuses after nationalisation in 1948 under control of the British Transport Commission.

It went on to become part of the Scottish Transport Group on 1 January 1969 along with David MacBrayne.

[10] In 1985, SBG was restructured as follows in preparation for deregulation:[11][12] In May 1988, it was decided to privatise the operating companies with this occurring in 1990/91.

[21][22] SBG Engineering had been formed to operate the central repair workshops inherited from six of the original seven operating subsidiaries (Alexander (Northern) not having had a separate engineering works).

The Larbert works was transferred to Midland Scottish in 1988[23] and the rest of the company was dissolved in March 1990 as a prelude to privatisation.