Private mortgage insurers last year diverted a record $753.2 billion of mortgage insurance premiums to captive reinsurance vehicles sponsored by their primary market lender customers, according to a new ranking and analysis by Inside Mortgage Profitability, an affiliated newsletter. The flow of MI premiums into lender captives rose 7.4 percent last year, a bit slower than the 12.7 percent increase reported in 2004. But the trends in sharing premiums with lender captives were by no… [One data table included]