The National Association of Realtors said the index, which tracks contracts of intention, rose 1.7 percent and hit its highest level since April 2010.
The index for October was revised lower to 104.6. In November, the index reached 106.4, 9.8 percent gain over November 2011.
As of November, the index has shown year-over-year improvements for 19 consecutive months, a sign of sustained improvement in the housing market.
"Even with market frictions related to the mortgage process, home contract activity continues to improve. Home sales are recovering now based solely on fundamental demand and favorable affordability conditions," Lawrence Yun, NAR's chief economist, said in a statement.
NAR said the pending home sales index rise 5.2 percent in the Northeast to 83.3.
The index rose a marginal 0.1 percent in the Midwest to 103.8. In the South it was unchanged at 117.2 and in the West, the index rose 4.2 percent to 110.1.