By Chris Dorrell Business activity in London remained comfortably in expansionary territory, according to a new survey, providing the engine driving the country out of a recession. Natwest’s London purchasing managers’ index (PMI) fell to 56.5 in February from 58.3 the month before. The 50 mark separates growth from contraction. Despite the decrease, the figures still pointed to a “robust expansion in activity” with London remaining the strongest-performing region in the UK. The survey showed that new orders increased for the sixth consecutive month, although at a slower pace than January. Con…