The North Western Gas Board was a state-owned utility providing gas for light and heat to industries and homes in the north-west of England. it was established on 1 May 1949 under the terms of the Gas Act 1948, and dissolved in 1973 when it became a region of the newly formed British Gas Corporation, British Gas North Western, as a result of the Gas Act 1972.
References
North Western Gas Board Wikipedia(Text) CC BY-SA