(Adds comments on housing market, outlook, new business volume)
Feb 7 (Reuters) - Genworth Mortgage Insurance Australia GMA.AX said on Wednesday its full-year net earned premium fell by 18 percent, in line with its guidance, due to changes in its premium earning pattern, while flagging a further decline in premium for 2018.
Net earned premiums fell to A$370.5 million ($292.9 million) from A$452.9 million, driving up its expense ratio during the year to 29.3 percent from 25.7 percent.
Australia's biggest mortgage insurer had earlier said its modified premium earning pattern reflected an expectation of risks, principally from factors including losses from mining related regions. company warned that net earned premiums in 2018 would further decline by about 25 percent to 30 percent, impacted by earnings curve review in 2017.
Full-year statutory net profit was A$149.2 million, down from A$203.1 million a year ago, while new business volume, measured by new insurance policies, fell over 10 percent.
"Housing market conditions (in Australia) are expected to ease further in 2018 as macro-prudential measures continue to take effect and record levels of new housing supply comes onto the market," the company said in a statement.
Genworth said its loss ratio, the ratio between premiums its customers pay and claims it pays out, rose 3.2 points during the year to 38.3 percent, due to lower net earned premiums.
It expects the 2018 loss ratio to be between 40 percent and 50 percent.
Genworth shares were trading 2.5 percent higher at 2322 GMT, compared with the benchmark index .AXJO , which was up 1.6 percent. ($1 = 1.2649 Australian dollars)