Mortgage applications decreased 0.7 percent from one week earlier, according to data from the Mortgage Bankers Association’s Weekly Mortgage Applications Survey for the week ending March 11, 2011.

The Market Composite Index, a measure of mortgage loan application volume, decreased 0.7 percent on a seasonally adjusted basis from one week earlier. On an unadjusted basis, the Index decreased 0.5 percent compared with the previous week. The Refinance Index increased 0.9 percent from the previous week and is the highest Refinance Index recorded in the survey since December 2010. The seasonally adjusted Purchase Index decreased 4.0 percent from one week earlier. The unadjusted Purchase Index decreased 3.2 percent compared with the previous week and was 15.5 percent lower than the same week one year ago.

The four week moving average for the seasonally adjusted Market Index is up 4.9 percent. The four week moving average is up 1.6 percent for the seasonally adjusted Purchase Index, while this average is up 6.6 percent for the Refinance Index.

The refinance share of mortgage activity increased to 66.4 percent of total applications from 65.5 percent the previous week. The adjustable-rate mortgage (ARM) share of activity decreased to 5.6 percent from 6.0 percent of total applications from the previous week.

The average contract interest rate for 30-year fixed-rate mortgages decreased to 4.79 percent from 4.93 percent, with points increasing to 1.07 from 0.87 (including the origination fee) for 80 percent loan-to-value (LTV) ratio loans. This is the lowest contract 30-year rate observed in the survey since the week ending January 14, 2011. The effective rate also decreased from last week.

The average contract interest rate for 15-year fixed-rate mortgages decreased to 4.03 percent from 4.17 percent, with points decreasing to 0.85 from 1.15 (including the origination fee) for 80 percent LTV loans. This is the lowest contract 15-year interest rate observed in the survey since the week ending December 3, 2010. The effective rate also decreased from last week.

The survey covers over 50 percent of all U.S. retail residential mortgage applications, and has been conducted weekly since 1990. Respondents include mortgage bankers, commercial banks and thrifts. Base period and value for all indexes is March 16, 1990=100.