Citadel Loan Servicing, which specializes in non-agency loans, has increased its maximum loan-to-value ratio to 80 percent from 75 percent. The change, which came about a week ago, is for fully documented loans.The privately held nonbank made the switch in response to borrower demand. The phones are ringing like a son-of-a-gun, said Citadel CEO Dan Perl. The Irvine, CA-based firm originates...