Commonwealth Bank chief executive Ralph Norris said yesterday that falls in market share in a wide range of businesses were the result of a strategy to take risk out of loan portfolios and avoid taking on unprofitable businesses on the deposit-side.Presenting the bank's results for the six months to December 2010, Norris said the bank had avoided picking up "hot money" in the business deposit market and had changed the lending criteria at its subsidiary, BankWest, which had suffered from high bad debt losses.Home loan market share fell from 26.1 per cent in June last year to 25.9 per cent at the end of December. Credit card share remained steady at 22.5 per cent over the same period, as did personal lending at 14.6 per cent. Share of household deposits fell from 27.5 to 26.9 per cent and share of business deposits fell from 22.9 to 21.3 per cent.Share of business lending, based on Australian Prudential Regulation Authority data, fell from 19.5 to 18.6 per cent over the six months to December. According to Reserve Bank data the fall was from 17.1 to 17 per cent.Other parts of the business that lost share include equities trading, risk business, New Zealand housing and business lending, New Zealand household deposits and New Zealand funds under management.In home lending, CBA's home lending book grew at an annualised rate of 9.2 per cent, compared with system growth of 8.4 per cent during the six months to June. In the December half, CBA's growth fell back to an annualised rate of 4.3 per cent, compared with system growth of 6.3 per cent.In business lending, CBA grew at an annualised rate of 3.4 per cent compared with a system fall of 1.5 per cent in the June half. In the December half, CBA's business loan book contracted 6.1 per cent compared with system growth of 0.6 per cent.Commonwealth Bank chief financial officer David Craig said the contraction in business lending was all on the institutional side. Lending to small- and medium-sized businesses was up 8.8 per cent, compared with system growth of one or two per cent.Craig said: "The BankWest story is very much an intentional one. We've quite deliberately got out of low-credit quality lending in this space and, on an annualised basis, our reduction in the target low-quality credit space was well over 20 per cent."We've grown market share in the stronger credit space in Bank West. "In business deposits, we quite deliberately didn't grow at system. System growth was extraordinarily high, at 20.6 per cent, but there is a lot of hot money moving around in the business market, and that hot money knowingly carries a requirement with it to carry offsetting liquid assets."It's either a no or negative margin business, and we're not in the business of profitless growth."