On 24 August 1986, the privatisation process started when the assets of the British Gas Corporation were transferred to British Gas plc, then owned entirely by the Government. In November 1986, shares in British Gas plc were offered for sale on the stockmarket and trading in British Gas shares commenced on 8th December 1986. During the 1989/90 financial year British Gas plc re-organised into three separate business units - Gas Business in Great Britain, Exploration and Production and Global Gas. By 1991 the 12 regions had been re-organised into 91 districts covering the whole of Britain. The Gas Business in Great Britain underwent further restructuring in 1994 when five Business Units were established :-
E&P and Global continued to operate in international markets. British Gas plc made a number of organisational changes during the early 1990‘s as the industry prepared for increased competition. On 17 February, 1997, British Gas plc demerged into two separate listed companies ; BG plc and Centrica plc.
British Gas‘s transportation and storage business (Transco) and the Exploration and Production (excl. North and South Morecambe gas fields), International Downstream, Research & Technology and Properties business's remained with BG plc. Further internal restructuring in 1999 led to the formation of BG Group with subsidiaries BG Energy Holdings Ltd, BG Transco plc and others.
British Gas‘s Gas Sales and Gas Trading, Services and Retail businesses, together with the gas production business of the North and South Morecambe gas fields were transferred to Centrica.