The Pending Home Sales Index jumped 10.4 percent in October after three months of declines. November's increase put the index at 100.1, up from 93.3 in October.
From November 2010, the index is up 5.9 percent, the NAR said.
"Housing affordability conditions are at a record high and there is a pent-up demand from buyers who've been on the sidelines, but contract failures have been running unusually high," said NAR Chief Economist Lawrence Yun.
"Some of the increase in pending home sales appears to be from buyers recommitting after an initial contract ran into problems, often with the mortgage," he said in a statement.
Region by region, the index jumped 8.1 percent in the Northeast and 3.3 percent in the Midwest. In the South, the index rose 4.3 percent. In the West, the index surged 14.9 percent, the NAR said.