U.S. mortgage activity fell last week with movement of long-term interest rates mixed, the Mortgage Bankers Association said Wednesday. In the week that ended Friday, U.S. mortgage activity fell 4.8 percent and refinancing fell 6 percent, the MBA said. Interest rates for 30-year, fixed-rate conforming mortgages rose from 3.63 percent to 3.65 percent with points falling from 0.45 to 0.39. The average interest rate for 30-year contracts on jumbo loans -- loans larger than $417,500 -- rose from 3.85 percent to 3.94 percent with points for 30-year jumbo loans dropping from 0.42 to 0.36. Interest rates for 15-year, fixed-rate mortgages fell from 2.96 percent to 2.95 percent. Points for 15-year, fixed-rate contracts fell from 0.36 to 0.35. The average rate for 30-year loans backed by the Federal Housing Administration were unchanged at 3.41 with points rising from 0.61 to 0.76. Average rate for short-term, adjustable-rate mortgages fell from 2.72 percent to 2.66 percent in the week with points averaging 0.33, unchanged from the previous week, the MBA said.