Out of all programs placed this year, more than half experienced a reduction in lead hull and liability premiums, with several seeing reductions of over 10 percent.

Capacity is suppressing high premiums by insurers, says the airline insurance report, and there is much competition for attractive risks. Insurers, however, are trending towards their preferred airline portfolios as opposed to the greater risk selection seen in 2011.

Renewal premiums moved down by 13 percent in April, when renewal premiums were at $122 million, but are at $145 million and down by 10 percent year-to-date.

Claims are currently lower than they were at this point in 2011, which was the lowest claims year in two decades. The most recent loss figure is $35 million in comparison with $65 million in April 2011. Factoring in minor losses, the cumulative loss is now $235 compared to $265 million year to date.

All surveyed insurers have a trading strategy in place for the bottom of the market cycle, the report continues. Shifting risk appetites mean that while some airlines find themselves with new capacity on their hands, others are losing it.

Spanair, with 25 aircraft valued at over $1 billion, has folded along with seven airlines included in Aon's 2011 data results.

In North America and Europe, regional exposure is falling in response to economic challenges and cultural events. Nine carriers project average fleet value increases of 10 percent or higher and more than 60 percent of programs predict passenger increases.

According to the International Air Transport Association, global traffic rose by close to 9 percent in February 2012 and cargo figures climbed to 5 percent against the previous year. The strong figures disguise factors which influence cross-global traffic, such as the Arab spring, a postponed Brazilian carnival, and the mid-winter Chinese New Year that deferred some deliveries until February, the report says.