National Australia Bank produced its first financial report under its new organisational structure, when it released its results for the six months to March yesterday.The restructure announced last year brought banking operations previously managed as personal banking, business banking, private wealth and wholesale banking into a single division called Australian Banking.It hasn't been the most auspicious start for the division that now produces more than 80 per cent of the bank's profit.Operating income of A$6.5 billion was down 0.9 per cent on the previous corresponding period and down 1.4 per cent on the September half. Expenses were up 4.8 per cent, year on year, and the only reason the division was able to report an increase in cash profit was that there was a significant reduction in the bad debt charge.NAB chief executive Cameron Clyne said the big reduction in the division's bad debt charge - down 36.8 per cent to $375 million over 12 months - was the result of a program to de-risk the bank.Clyne said the other highlight in the division's performance was its increase in market share in home lending, household deposits and business deposits (see results at a glance). Loss of share in business lending was a result of the de-risking process.The bank's chief financial officer, Craig Drummond, said the flat result of the division was due to a combination of subdued business lending volumes, increasing competition impacting lending margins, higher investment spend (including regulatory spend) and some additional staff costs related to higher mortgage volumes.NAB is often described as a business banking powerhouse but 59 per cent of the Australian Banking division's lending is mortgages. This percentage has increased from 46 per cent in 2001.Clyne said the business was well placed to take advantage of any pick-up in demand for lending.However, analysts expressed some concern that the bank didn't have more to show for all the de-risking and market share growth.