Mortgage application filings increased 1.3% this past week as refinance and purchase activity picked up, an industry trade group said Wednesday. The Mortgage Bankers Association reported that the market composite index – a measure of loan application volume – jumped 1.3% on a seasonally adjusted basis from last week. The refinance index also edged up 1.3%, while the purchase index grew 1.1% over a week ago. The increases in both categories were driven by government loans, the MBA said. The government purchase index alone shot up 2.4%. The refinance share of mortgage activity remained unchanged overall, representing 79.1% of all activity. In terms of interest rates, the adjustable-rate mortgage fell to 6% from 6.4% of total applications. The 30-year, FRM increased to 4.25% from 4.18%, while the 30-year, FRM on jumbos increased to 4.59% from 4.49%. The 30-year fixed backed by the FHA grew to 4.06% from 4.05%, while the 15-year FRM increased to 3.53% from 3.49%. The 5/1 ARM increased to 3.03% from 3.02%. The average loan size in the U.S. hit $210,863, down from $212,736 in August. The average loan in refinancing was valued at $237,632, compared to $241,323 a month ago. Write to Kerri Panchuk.