WASHINGTON (AP) — The number of Americans who signed contracts to buy homes rose in March to the highest level in three years.

The National Association of Realtors says that its seasonally adjusted index for pending home sales rose 1.5 percent to 105.7. That's the highest since April 2010, when a homebuyer's tax credit boosted sales. It's also above February's reading of 104.1.

Signed contracts are 7 percent higher than they were a year earlier. There is generally a one- to two-month lag between a signed contract and a completed sale.

Still, sales are being held back by limited supply. Sales of previously occupied homes dipped in March to a seasonally adjusted annual rate of 4.92 million, down from 4.95 million in February.