Commercial lending activity fell heavily in August, after recording steady growth in recent months.According to the latest Australian Bureau of Statistics lending figures, commercial finance commitments fell 16.3 per cent in August, compared with the previous month (in seasonally adjusted terms).Lenders wrote A$38.7 billion of commercial loans - down from $48.5 billion in July.However, the August total was a 7.8 per cent increase over the value of commercial loans written in August last year.Looking at commercial finance commitment by purpose, almost all categories were down in August. These included construction finance, wholesale finance, property purchase, purchase of plant and equipment and motor vehicle finance.The only growth came from refinancing and lease finance, which was up 8.7 per cent.CommSec Research said in a note that it was likely that the slide was a one-month aberration, given that the business environment was improving.