* Compares to previous high forecast of $15 bln
* Storm surge to blame for most of increase
* Does not count gov't flood program losses
Nov 26 (Reuters) - Disaster modeling company AIR Worldwide raised its estimate of insured losses from superstorm Sandy substantially to between $16 billion and $22 billion.
The firm's initial estimate, the day after the storm hit, had been for $7 billion to $15 billion in losses. AIR said on Monday that higher storm surge damage accounted for most of the change.
AIR peer Eqecat has forecast insured losses of up to $20 billion, while peer RMS says losses could hit $25 billion. In all three cases, Sandy would be the second-costliest catastrophe in U.S. history, behind only Hurricane Katrina.
AIR's estimate also excludes losses incurred by the federal government's National Flood Insurance Program, which will likely seek a bailout amid expected losses of up to $12 billion.