The National Association of Realtors said the index, which tracks contracts of intention, said its Pending Home Sales Index rose 4.5 percent to 105.9 in January after sliding 4.3 percent in December.
In January, the index stood at 9.5 percent above January 2012, making it 21 consecutive months that the index has improved on a 12-month basis.
"Favorable affordability conditions and job growth have unleashed a pent-up demand," said NAR Chief Economist Lawrence Yun in a statement.
"Over the near term, rising contract activity means higher home sales, but total sales for the year are expected to rise less than in 2012, while home prices are projected to rise more strongly because of inventory shortages," Yun said.
The Pending Home Sales Index for the Northeast rose 8.2 percent to 84.8, while the index in the Midwest rose 4.5 percent to 105. The index rose 5.9 percent in the South to 119.3 and 0.1 percent in the West to 102.1, NAR said.
The index is a comparison to the monthly average for 2001, the first year the index was monitored, which was assigned a value of 100.