The National Association of Realtors said the index that tracks contracts of intention rose 1.5 percent month-to-month to 105.7.
The NAR said it had revised its February reading for the index to a lower number, 104.1.
In March, the 23rd consecutive month of improvements on an annual basis, the index was 7 percent higher than March 2012.
"Contract activity has been in a narrow range in recent months, not from a pause in demand but because of limited supply. Little movement is expected in near-term sales closings, but they should edge up modestly as the year progresses," NAR Chief Economist Lawrence Yun said in a statement.
The Pending Home Sales Index for the Northeast held steady in March 82.8, while the index in the Midwest rose 0.3 percent to 103.8. The index rose 2.7 percent in the South to 120 and 1.5 percent in the West to 102.9, NAR said.
The index is a comparison to the monthly average for 2001, its first year, which was assigned a value of 100.