Fannie Mae is lowering its maximum loan-to-value ratio to 95 percent come November, a move that could lead to more business going to the FHA. The policy change was confirmed by the GSE when it recently sent out an update to users of its automated underwriting program, Desktop Originator. It also means that mortgage insurers could lose business at a time when many have shown a new willingness to take on more credit risk amid improving delinquencies and earnings.