Formed as a result of the Gas Act 1986 used as an instrument for the privitisation of the Brtish Gas Corporation. Shares in the newly privatised company were floated on the 8th December 1986. The company was demerged into several smaller parts, in 1997, Centrica, BG Group and Transco.

Formed in 1948 as part of the nationalisation of the electricity industry by the Electricity Act 1947. The assets of the Board passed to Norweb plc in 1990. Norweb plc was acquired by North West Water plc in 1995, the combined water and electricity companies becoming United Utilities (UU).

Energi was the brand name of Norweb Gas Limited. Norweb Gas Ltd had originally been formed in 1992 as Communitytrade Limited a further change of name occured in 1992 when the company became known as Northern Gas Limited. A further change of name in 1994 changed the name of the company Norweb Gas Limited, a Special Resolution passed on the 11th May 1999 the authorised share capital of the company was increased from £500,000 to £29,750,000 by the creation of 29,250,000 redeemable preference shares with a value of £1 each. In March of 1999, NORWEB plc purchased the 25% shareholding in Norweb Gas from UtiliCorp UK Ltd from that date the company became a wholly owned subsidiary of NORWEB plc In the financial year ending 2000, United Utilities PLC announced its intentions to sell NORWEB Energi which included NORWEB Gas. The business was sold to TXU Europe in August 2000, in 2002 TXU was later acquired by Powergen.