The Mortgage Bankers Association (MBA) today released its Weekly Mortgage Applications Survey for the week ending December 15. The Market Composite Index, a measure of mortgage loan application volume, was 647.6, a decrease of 10.2 percent on a seasonally adjusted basis from 721.2 one week earlier. On an unadjusted basis, the Index decreased 11.6 percent compared with the previous week and was up 13.9 percent compared with the same week one year earlier. The seasonally adjusted Refinance Index decreased by 14.6 percent to 1968.8 from 2304.4 the previous week and the Purchase Index decreased by 5.9 percent to 436.5 from 463.8 one week earlier. The seasonally adjusted Conventional Index decreased by 10.7 percent to 963.9 from 1079.4 the previous week, and the seasonally adjusted Government Index decreased 3.1 percent to 120.3 from 124.1 the previous week.   The four week moving average for the seasonally adjusted Market Index is up 0.9 percent to 653.9 from 647.9. The four week moving average is up 2.1 percent to 433.4 from 424.6 for the Purchase Index, while this average is up 0.4 percent to 2003.1 from 1994.8 for the Refinance Index. The refinance share of mortgage activity decreased to 50.8 percent of total applications from 52.6 percent the previous week. The adjustable-rate mortgage (ARM) share of activity decreased to 23.6 from 24.9 percent of total applications from the previous week. The ARM share is at its lowest level since October 2003. The average contract interest rate for 30-year fixed-rate mortgages increased to 6.10 from 6.02 percent, with points decreasing to 0.93 from 1 (including the origination fee) for 80 percent loan-to-value (LTV) ratio loans. The average contract interest rate for 15-year fixed-rate mortgages increased to 5.82 percent from 5.75 percent, with points decreasing to 0.99 from 1 (including the origination fee) for 80 percent LTV loans. The average contract interest rate for one-year ARMs increased to 5.82 percent from 5.76, with points increasing to 0.83 from 0.81 (including the origination fee) for 80 percent LTV loans.