Major mortgage companies snagged an estimated $400 million in revenue through captive reinsurance programs with private MIs during 2002, up from $300 million the year before. Most of the growth in captive reinsurance volume appears to result from increased business levels rather than an expansion of the number of captive reinsurance arrangements, according to an analysis by Inside Mortgage Finance, an affiliated newsletter. The share of new MI premiums being ceded by insurers to