The average fee charged by Fannie Mae and Freddie Mac to lenders rose last year, while payments collected on the Home Affordable Refinance Program dropped off, according to the Federal Housing Finance Agency.The fourth-annual FHFA study found that the average total guaranty fee charged by Fannie and Freddie on single-family mortgages was 28 basis points in 2011, compared to 26 bps in 2010. When HARP and flexible refinance loans were excluded, the FHFA said the total average g-fee increased to 26 basis points in 2011 from 24 basis points in 2010. “That change reflects increases in both the average ongoing fee and the average upfront fee,” the FHFA report said.