Sales of new homes plunged in November by the largest amount in nearly 12 years, providing the most dramatic evidence yet that the red hot housing market during the past five years is starting to cool down.

The Commerce Department reported Friday that new single-family homes were sold at a seasonally adjusted annual rate of 1.245 million units last month, a drop of 11.3 percent from October, when sales had surged to an all-time high.

Last month’s decline was even bigger than the 8.7 percent drop-off that Wall Street analysts had been expecting. While sales of both new and existing homes are still on track to set records for a fifth straight year in 2005, analysts are forecasting sales will decline in 2006 as the housing boom quiets down.