A timeline of key dates in the history of Northern Gas Networks:
- 24 August 1986 – Assets of British Gas Corporation transferred to British Gas plc (integrated gas company for UK)
- February 1997 – The shareholders of British Gas plc approved the demerger of Centrica plc. British Gas plc was renamed BG plc.
- December 1999 – BG plc completed a financial restructuring which resulted in the creation of a new parent company, BG Group plc.
- 23rd October 2000 – BG Group plc completed the demerger of Lattice Group plc creating two separate companies.
- 21st October 2002 – National Grid plc merged with Lattice Group plc to form National Grid Transco plc.
- 1st June 2005 – Northern Gas Networks acquired by Cheung Kong Infrastructure when National Grid Transco sold four networks including Northern Gas Networks, SGN and Wales and the West Utilities. National Grid Transco became National Grid.