The FTSE 100 index opened down 17.45 points, 0.2%, at 8,206.53. The FTSE 250 was up 36.75 points, 0.2%, at 20,628.15, and the AIM All-Share was up 1.42 points, 0.2%, at 726.82.
European natural-gas prices fell in early trade but remain elevated on the month due to colder weather forecasts and supply concerns following the suspension of Russian gas transit through Ukraine.