WASHINGTON —

Previously owned home sales fell unexpectedly in June as tight supply and increasing rates for mortgages imperiled the real-estate market recovery in the United States.

Purchases fell 1.2 percent to a 5.08 million annualized rate, the National Association of Realtors reported Monday in Washington.

The median forecast of 79 economists surveyed by Bloomberg called for a 5.26 million pace. Demand was the second- strongest since November 2009 following May’s downwardly revised 5.14 million rate.

First-time buyers are having difficulty finding properties for less than $100,000 as a lack of inventory pushes up property values, and higher mortgage rates are also starting to cool demand for more expensive houses in the West and Northeast, the real-estate agents group said.

Federal Reserve Chairman Ben Bernanke last week said housing was one of the bright spots for growth and added that policy makers will monitor the recent jump in borrowing costs to ensure it won’t derail the recovery.

“Demand is still fairly strong, but this is where the inventory constraints come into play,” said Richard Moody, chief economist at Regions Financial Corp. in Birmingham, Ala., who predicted sales would decline to a 4.99 million pace. “Inventories still remain fairly tight, particularly on the low end of the price scale.”

Sales climbed 8.2 percent from June 2012 before adjusting for seasonal variations, Monday’s report showed.

The median price of an existing home climbed 13.5 percent to $214,200 last month from $188,800 a year earlier.

The number of properties on the market increased 1.9 percent to 2.19 million, the fewest for any June since 2001. These data aren’t adjusted for seasonal changes, so it’s important to compare figures for the same month each year.