Mortgage applications fell last week as purchases and refinancing volume slid, and mortgage rates likely rose slightly, according to a weekly report published Wednesday morning by the Mortgage Bankers Association. The MBA’s market composite index dropped to 621.6 for the week ended May 16, a drop of 7.8 percent from one week earlier. The application index is calibrated to March 16, 1990; a reading of 621.6 means that application activity was roughly 6.2 times greater than when the index was first established. Refinancing activity, usually the driver of overall application volume, fell 8.7 percent as mortgage rates appeared to have inched higher; the MBA said that average rates on a 30-year fixed-rate mortgage rose 8 basis points during last week. Purchase application activity — usually used by economists to predict the direction of the housing market — feel 6.9 percent. Surprisingly, FHA application activity took a sharp dip as well, falling 6.8 percent; the drop was one of the few weekly decreases posted for FHA applications so far this year. The share of adjustable-rate mortgages as a portion of overall application activity continued to rise as well, hitting its first double-digit total this year at 10.0 percent, the MBA said. For more information, visit http://www.mortgagebankers.org.