For the first time in four months, new single-family home sales unexpectedly fell in December and the median home price dropped to dampen some of the hopes that the housing sector will boost the economy this year.

Recently, the Commerce Department said sales decreased 2.2 percent to a seasonally adjusted 307,000-unit annual rate. Sales were forecasted at a 320,000-unit rate in an economist poll by Reuters and sales pace of November was revised slightly lower.

The housing market remains constrained by high unemployment, falling prices, and an oversupply of unsold homes, after a bust that triggered the 2007-09 recession. Sales fell in two of the four regions of the country, including a 10.1 percent drop in the South, where most new homes were sold. The median sales price for a new home fell 2.5 percent to $210,300 last month, which is the biggest drop in four months. The median price was down 12.8 percent compared to December last year.

Last month, there were a record low 157,000 new homes on the market and at the sales pace of December it would take 6.1 months to clear them, up from 6.0 months in November. Sales were down 6.2 percent from the prior year for all of 2011, with 302,000 new single-family homes being sold.