Created in 1997 when the old British Gas divested Centrica, BG is now a leading player in the lucrative liquefied natural gas industry. Avoiding the politics of pipelines, BG ships its LNG all over the world in special tankers. It made £4.2bn profit in the first nine months of 2012 and is now investing £10bn in liquefying gas from coal seams in Australia. But the shale gas boom in the US could dent revenues there, and a cut in production forecasts hit the share price last month. With veteran CEO Frank Chapman retiring next year, BG could become a takeover target.