Mortgage aggregator AFG put a positive spin on its flat 2018/19 result by pointing out that half its gross margin was generated outside its mortgage business last financial year. It expects this business diversification to continue.AFG has invested in commercial lender and fund manager Thinktank, which provides commercial loans to the AFG network, and it has a growing residential mortgage-backed securities business, which is now worth more than $2 billion. Both contributed to earnings.Its 30 per cent stake in Thinktank added $1.5 million to pre-tax profit.The company announced on August 12 that it had launched a takeover bid for a rival mortgage aggregator, Connective Group. The $120 million deal would create a mortgage distribution network with more than 6500 brokers.Overall, AFG's commission and other income rose 3.4 per cent to $569.7 million and securitisation interest income rose 39.8 per cent to $73.1 million. Total operating income rose 6.5 per cent to $642.8 million.But with the cost of sales and other expenses rising at about the same rate net profit was down 0.8 per cent to $33 million.Residential mortgage settlements fell 11 per cent to $31.3 billion. AFG Securities settlements more than doubled to $1 billion. The company said AFG Securities was giving borrowers greater choice in segments such as near prime.