@ JohnMcGhie
I have heard that there are one or two insurers which still offer this ( which really surprises me) , though off the top of my head I couldn't give you a name.
The reason I am surprised that anyone still offers it is that most travel insurers re-wrote their policies to exclude financial collapse in the wake of the 11 September attacks as a large number of airlines went bung in quick succession, so it is not as if it is a recent development.
The risks were just too great to keep offering that sort of cover and given the current state of the industry I can't see most insurers bringing it back any time soon... unless of course people are prepared to trade the extra cover for significant additional premiums.
Good luck... and if you find a company which offers it please post... I would be very interested to know ( and I am sure that a lot of others would be too) .