Britain's leading shares are expected to open little changed on Tuesday, while early attention is expected to focus on oil giant BP. Financial bookmakers anticipate that the FTSE 100 index will open a point or so down from Monday's 16-point higher finish of 4,864.9 points, with a fall in the crude price seen holding back heavily weighted oil majors early on. Matt Buckland, a trader at brokers CMC, said Monday's rise on Wall Street had left traders in a generally upbeat mood, which could boost European share markets. "However, a small retreat in oil prices away from the $55 mark is likely to weigh on the likes of Shell and BP - both significant constituents in the FTSE - so this may well be sufficient to peg back the London start," he said.