Guaranty fees that Fannie Mae and Freddie Mac charge lenders will rise later this year following a directive from the GSEs’ conservator but industry officials note concern about the potential unintended consequences of spurring additional, future g-fee hikes too soon. Late last week, the Federal Housing Finance Agency announced g-fees on single-family will rise another 10 basis points. The increase is effective Dec. 1, 2012, for loans exchanged for mortgage-backed securities, and on Nov. 1, 2012, for loans sold for cash.