AFG brokers have been sending more business to non-major lenders but have shown less interest in their own white-label product.
The big four banks and their sub-brands accounted for 71.7 per cent of AFG mortgages in October. That compared to a share of 72.3 per cent in November 2013.
The non-majors increased their share from 27.7 per cent to 28.3 per cent during that period.
The two big movers were Suncorp, which increased its market share from 4.8 per cent to 8.2 per cent, and Bank of Queensland, which climbed from 0.5 per cent to 2.6 per cent.
ME Bank suffered a loss of market share from 3.5 per cent to 1.6 per cent, while AFG's white-label offering fell from 3.3 per cent to 1.9 per cent.
AFG's general manager of sales and operations, Mark Hewitt, said he was pleased by the growth of the non-major sector.
"It is very encouraging from a competition perspective to see borrowers more and more willing to explore alternatives," he said.
"Suncorp are a great example of this. Traditionally they have struggled outside their home state of Queensland, however through delivering on a combination of customer value and service, they have reached an all-time market share high of 8.2 per cent."
[Related: AFG enjoys 17.2pc jump in volumes]