Suncorp chief executive Steve Johnson has made it one of his top priorities to improve the banking division's performance in the mortgage broker channel. The bank suffered a loan book contraction during the December half, largely as a result of "elevated processing times" for broker applications.Suncorp reported net profit of A$642 million for the six months to December, an increase of 156.8 per cent. The result includes a $293 million gain on the sale of two businesses, Capital SMART and ACM Parts.Net profit from ordinary activities, based on the performance of continuing operations, fell 7.2 per cent to $348 million.Revenue was down 6.1 per cent to $7 billion.Earnings from the banking and wealth division fell 6.6 per cent to $171 million, while earnings from insurance fell 3.9 per cent to $123 million and earnings from the New Zealand division fell 8.1 per cent to $102 million.In the insurance division, premium growth was offset by higher than anticipated natural hazard costs.The New Zealand result was also affected by higher natural hazard costs, as well as remediation relating to the incorrect application of customer discounts.In the banking and wealth division, the home loan book contracted 1.4 per cent to $47.2 billion over the half.Suncorp chief financial officer Jeremy Robson said the impact of low system growth was compounded by "elevated processing times", particularly in the broker channel.The net interest margin rose from 1.9 per cent to 1.92 per cent. This was largely due to strong growth in at-call deposits.Net interest income rose 1.5 per cent to $594 million, while non-interest income fell 47.8 per cent to $12 million. The big fall was attributed to a one-off GST adjustment.The impairment loss was $1 million - down from $7 million in the previous corresponding period.Operating costs rose 5.9 per cent, reflecting higher regulatory and compliance costs and an increase in technology spend. The cost-to-income ratio was around 60 per cent.Johnson said the positives in the result were growth in the Australian home and motor businesses and growth in the bank's net interest margin.He said he had made some adjustments to the structure of the business since he joined last August but he acknowledged he had a way to go.In banking, apart from fixing the problems in the broker channel, he is keen for Suncorp to make more of its home ground advantage in Queensland. He is planning to increase the bank's footprint in the state and target more aggressive growth there.He also has a raft of digitisation and automation projects planned.