Natural disasters cost insurers $65 billion last year, with the US accounting for nine-tenths of the bill.

Superstorm Sandy has prompted payouts of $25 billion, a leading insurance company said today.

However, Munich Re said that the total insured losses worldwide were down from a record $119 billion in 2011, when devastating earthquakes in Japan and New Zealand cost the industry dear.

The company said total economic costs in 2012 from natural disasters worldwide - including uninsured losses - amounted to $160 billion, compared with the previous year's $400 billion.

Sandy, which battered eastern coastline areas at the end of October, killed at least 125 people in the US and 71 people in the Caribbean. New York, New Jersey and Connecticut were the hardest-hit US states.

Munich Re estimated insured losses from Sandy at $25 billion and total losses at $50 billion, though it cautioned that the figures are "still subject to considerable uncertainty."

That made it the year's most costly disaster - but several other events in the US meant that the country accounted for 90% of insured costs and 67% of overall losses, the company said. Over the past decade the well-insured US on average accounted for 57% of insured losses and 32% of overall costs every year.

The lengthy drought that seared swathes of the US last summer produced 2012's second-biggest insurance bill. Munich Re said the insured losses, being picked up by a public-private crop insurance programme, totalled between $15 billion and $17 billion - most of the $20 billion worth of overall crop losses.

That was the biggest loss in US agricultural insurance history, comparing with average insured losses of about $9 billion a year, Munich Re said.

Severe storms and tornadoes in March, late April, June and July completed Munich Re's list of the five costliest disasters for insurers in 2012, each costing $2.5 billion.

Back-to-back earthquakes in northern Italy last May caused total losses of $16 billion, but only one-tenth of that was covered by insurance. Deadly flooding in China in July caused damage worth $8 billion, but only a small fraction of that - $180m - was insured.

Munich Re said that last year's heavy losses from weather-related disasters in the US "showed that greater loss-prevention efforts are needed."

Munich Re's main business is reinsurance, which means offering backup policies to companies that write primary insurance policies. Reinsurance helps spread risk so that the system can handle large losses from natural disasters.