During the third quarter, total Fannie Mae and Freddie Mac servicing related to single-family mortgage-backed securities nudged slightly higher, according to a new Inside The GSEs analysis and ranking.The two GSEs had a combined $4.5 trillion in single-family MBS outstanding at the end of September. That was up 0.4 percent from the previous quarter, but down 0.4 percent from a year ago. Total GSE single-family servicing is somewhat higher because both Fannie and Freddie have retained portfolios of unsecuritized mortgages. Fannie MBS servicing was actually down 0.2 percent during the third quarter and off 2.3 percent from September 2015. Freddie servicing was up 1.6 percent for the quarter and up...