The major banks' share of home loans written by one of the country's biggest broker groups fell during the June quarter.Aggregator AFG, which claims a 10 per cent share of the mortgage distribution market, issued its latest competition index yesterday. It showed the big banks' share falling from 79.4 per cent in March to 75.2 per cent in June.The big mover has been Macquarie Bank, whose share of AFG's business has increased from 2.5 per cent in January to 5.5 per cent in June.The non-majors' share of fixed-rate lending was slightly higher than the overall figure; they accounted for 25.3 per cent of fixed-rate loans compared with an overall share of 24.8 per cent.Non-majors increased their share among first-home buyers from 22.1 per cent in March to 25.6 per cent in June.Not all the big banks lost share, however. AFG brokers did more business with Commonwealth Bank's subsidiary, Bankwest, and Westpac picked up a few percentage points of share.AFG's strongest relationship is with Commonwealth Bank. CBA and Bankwest together accounted for 26 per cent of AFG's business in June.