New sales of single-family homes rose 17.5% in December from a month earlier to the highest level since April when the homebuyer tax credit propped up the market. The Commerce Department said the seasonally adjusted rate of 329,000 units last month was up from a downwardly revised 280,000 for November, yet still 7.6% below 356,000 a year earlier. Analysts surveyed by Econoday expected December home sales to climb to 300,000 with a range of estimate between 276,000 and 320,000. A Briefing.com survey projected home sales to remain flat at 280,000. The median sales price of new homes sold last month was $241,500 and the average price was $291,400. There were about 190,000 new houses for sale at Dec. 31, representing a supply of 6.9 months, according to the joint release from the Census Bureau and the Department of Housing and Urban Development. The new home supply is down from 8.4 months in November and at the lowest point since April. The agencies estimate 321,000 new homes were sold in 2010, down 14.2% from 375,000 for 2009. Earlier Wednesday, the Mortgage Bankers Association said its market composite index for mortgage applications fell 12.9% on a seasonally adjusted basis for the week ended Jan. 21, as refinancing activity declined 15.3% Write to Jason Philyaw.