WASHINGTON (AP) — U.S. sales of existing homes increased 1.1 percent on a monthly basis in March, which suggests that buyers are undeterred by the dwindling number of properties available on the market.

The National Association of Realtors said Monday that homes sold last month at a seasonally adjusted annual pace of 5.60 million, up from 5.54 million in February. This sales rate is higher than the 2017 total, but March sales were down slightly over the past 12 months.

The housing market continues to be in the grip of an inventory crunch that has restricted sales and growth in home ownership. Even as the overall economy has improved, there has been a 7.2 percent decline in listing from a year ago to just 1.67 million homes. The decline in listings could bottom out later this year because there has been a recent uptick in people listing homes that are then quickly purchased. But rising mortgage rates are also making it less likely that homeowners will choose to sell in order to buy another property at a higher interest rate.

Nor have gains in new construction been enough to make up for the decline in inventories.

"Demand is outstripping supply, and builders have been constrained in their efforts to add new homes by tight labor, zoning restrictions, and most recently a run-up in materials costs," said Stephen Stanley, chief economist at Amherst Pierpont Securities.

Homes stayed on the market for 30 days in March, down from 34 days a year ago in a sign that the lack of inventory is prompting buyers to sign contracts quickly.

The shortage is also causing prices to grow at roughly double the pace of wages. The median sales price has risen 5.8 percent from a year ago to $250,400.

Home sales rose last month in the Northeast and Midwest, but they fell in the South and West.

Mortgage buyer Freddie Mac said the average rate for a 30-year fixed rate mortgage had climbed to 4.47 percent last week. That is the highest average since January 2014, something that could dissuade people from listing their homes for sale because it would also mean that they would have to pay a higher mortgage rate for any replacement homes they bought.