NEW YORK (Dow Jones/AP) ? Catastrophe bonds have traditionally been linked to the risk of natural disasters such as earthquakes and hurricanes in highly developed regions.

But the market is expanding as insurers look to offload their exposure to these same risks in rapidly developing areas. Bonds linked to the risk of less familiar hazards such a flu pandemic also represent a growth area, according a report published on Monday by Moody?s Investor Services.

?We are seeing catastrophe bond coverage extending to familiar hazards in new regions, such as earthquakes in Mexico and cyclones in Australia, and to some new hazards, such as ice storms, floods, and even general liability due to losses in the oil and gas industry,? said Rodrigo Araya, Moody?s senior vice president and co-author of the report.

Of the roughly 45 catastrophe bonds, or ?cat? bonds, that Moody?s has rated since 1997, nearly all have been linked to earthquakes, hurricanes and other windstorms.

But the ratings agency said other kinds of natural disasters, such as ice storms and floods occur often enough, that it?s possible to model the risks associated with them reasonably accurately.

Since 2003, Moody?s has also rated a few extreme mortality cat bonds with risks tied to extreme mortality risk associated with events such as a flu pandemic or terrorist attack.

The ratings agency said modelling mortality rates in a influenza outbreak presents some special challenges: Although pandemics have occurred in the past, society has changed in ways that is likely to alter the frequency and severity of future pandemics. For example, advances in medical science would tend to reduce the spread of an influenza virus, while the relative ease of international travel would tend to have the opposite effect.

It can be even more difficult to model mortality risk from other types of events such as a nuclear, biological, chemical or radioactive terrorist attack.