The London stock market opened higher on Tuesday with the FTSE 100 index up by 25.20 points, or 0.45 percent, to 5,669.74 points at around 08:40 GMT. Shares in Regus and Cairn Energy gained by 8.86 percent and 7.71 percent respectively in early trading and Legal & General Group also increased by 6.15 percent. While shares in Carpetright dropped by 10.37 percent, the top loser in early trading. 