WASHINGTON – Mortgage applications nationwide fell last week to the lowest level this year, as both purchase and refinance applications declined, the Mortgage Bankers Association reported today.

The trade group’s Market Composite Index – a measure of mortgage loan application volume – fell 7.6 percent to a seasonally adjusted 603.8 points in the week ended Dec. 21, after plunging 19.5 percent the week before, in a two-week decline that Bloomberg News called the largest since April 2004. But compared with a year ago, the index rose 9.9 percent.

Its seasonally adjusted Refinance Index fell 8.5 percent to 1,915.3 points after plunging 27.3 percent in the week ended Dec. 14. The Purchase Index fell 7.8 percent to 292.3 points, after falling 13.1 percent the week before.

Refinancing accounted for 53.0 percent of loan applications last week, down slightly from the previous week’s 53.2 percent, the MBA found. Adjustable-rate mortgages (ARMs) increased to 10.4 percent of total applications from 9.9 percent in the week ended Dec. 14.

Interest rates fell, with the average 30-year fixed-rate mortgage costing borrowers 6.10 percent, down from 6.18 percent the week before, while the rate on the average one-year ARM dipped to 6.03 percent from the previous week’s 6.48 percent.

Going forward, “weak home sales will continue to weigh on housing starts and residential construction, while weak mortgage-equity withdrawals will weigh on consumer spending,” Steven Wood, president of Insight Economics LLC in Danville, Calif., told Bloomberg News.

The MBA’s Weekly Application Survey – conducted each week since 1990 – covers about 50 percent of all U.S. retail residential mortgage originations. The base period and base value for all indexes is March 16, 1990 = 100.

The Mortgage Bankers Association is a trade group representing the real estate finance industry, with 3,000 member companies that include mortgage firms, commercial banks, thrifts, life insurance companies and others. Additional information, including the MBA’s Weekly Application Survey, is available at www.mortgagebankers.org.