Mortgage brokers are writing record levels of fixed-rate loans, as borrowers take advantage of low fixed rates to cover the risk of interest rate increases over the next couple of years.Yesterday, AFG reported that fixed-rate loans accounted for 30.7 per cent of the business its brokers wrote in April. AFG's fixed-rate lending has increased from 18.7 per cent of total mortgage sales since December.AFG's general manager of sales and operations, Mark Hewitt, said: "Borrowers are choosing to lock in historically low rates."AFG processed 8005 loans in April, worth $3.2 billion - an increase of 0.65 per cent over the previous month. Mortgage Choice reported that fixed-rate loans accounted for 28 per cent of the business its brokers wrote in April - the highest level for five years. Mortgage Choice's fixed-rate business has increased from 18.4 per cent in February.Mortgage Choice spokesperson, Belinda Williamson, said: "A number of lenders are still offering highly competitive fixed-rate loans. It is not surprising borrowers have been taking advantage of the deals on offer."According to Reserve Bank figures, the average three-year fixed home loan rate is 5.45 per cent, compared with the average discounted variable home loan rate of 5.65 per cent.