"Contract activity has been in a narrow range in recent months, not from a pause in demand but because of limited supply," said Realtors chief economist Lawrence Yun in a release. "Little movement is expected in the near-term sales closings, but they should edge up modestly as the year progresses.
(Read More: Despite Rising Demand, Some Builders Slow Production)
Listings were down 17 percent in March from a year earlier, according to the association, with several factors affecting inventories. Millions of Americans still owe more on their mortgages than their homes are worth, and that makes it impossible for them to move without incurring major expense.
Others are watching home prices rise and may be waiting to see just how high they go before listing their homes.
Meanwhile, home builders, while trying to ramp up production, are faced with a lack of land, labor and materials. Single-family starts were at a seasonally adjusted annual rate of just 619,000 units, an improvement from the worst of the crash but far below historical norms.
(Read More: Map: Tracking the US Real Estate Recovery)
Regionally, the pending home sales index was unchanged in the Northeast from February, up 0.3 percent in the Midwest, up 2.7 percent in the South and up 1.5 percent in the West.
Existing home sales in March, based on closings, fell just under one percent in March. While higher than a year ago, home sales appear to have leveled off, despite this being the normally busy spring season.
(Read More: Government Mortgage Fix Is Failing)