The big banks' share of home loans written by one of the country's biggest mortgage aggregators, AFG, declined last year.Yesterday, AFG reported that 73.5 per cent of the loans written by its brokers in December were funded by the Big Four banks and their subsidiaries - down from 78.4 per cent in February last year.Over the same period, "non-major" share (regional banks, mutuals, mortgage specialists and foreign-owned banks) increased from 21.6 per cent to 26.5 per cent.The continuation of strong deposit inflows and an increasingly active securitisation market have provided smaller lenders with the funds to pursue growth in the mortgage market.The non-majors were particularly strong in the fixed rate segment. Their share grew from 13.6 per cent in February last year to 38.2 per cent in December.The major bank that suffered the biggest fall in its share of AFG's business was Commonwealth Bank, whose share fell from 21.4 per cent in February to 16.4 per cent in December. ANZ's share grew over the same period, while Westpac and NAB were steady.Among smaller lenders, ING Direct, Macquarie Bank, ME Bank, Heritage Bank and Bank of Queensland picked up share.