Heavy losses from floods, storms, earthquakes and bushfires have pushed a number of general insurers into underwriting loss over the past year.The combined ratio of Australia's biggest general insurer, Suncorp, rose from 97.9 per cent in the year to June 2010, to 109.3 per cent in the 2010/11 financial year.The combined ratio measures claims plus underwriting expenses as a percentage of premium income; a combined ratio of over 100 per cent indicates an underwriting loss.Allianz Australia's combined ratio fell from 95.9 per cent, at December, to 105.2 per cent for the June half Calliden Group's combined ratio rose from 95.7 per cent to 109.8 per cent over the same period. RACQ Insurance's combined ratio went up from 100 to 101.5 per cent, and Zurich Australian Insurance's rose from 92 per cent to 105.7 per cent. In all, six out of the 13 general insurers in the latest KPMG general insurance survey, released yesterday, moved from underwriting profit to loss over the past year.The Queensland floods in December and January cost the industry $2.4 billion, the Queensland cyclone $1.2 billion, the Melbourne storms $384 million and the Victorian floods $114 million.The cost of natural disasters in 2010, at more than $2.5 billion, eclipsed the cost of the Sydney hailstorms in 1999. Costs so far this year are up at around $1.5 billion.KPMG's insurance partner, Ian Moyser, said the industry was responding with some "transformational efforts" to cut costs. Core claims systems are being replaced. This is improving the management of long-tail claims and reducing the leakages that arise from poor claims handling.