WASHINGTON — Americans bought fewer homes in June than May, suggesting the weak economy could be slowing a modest housing recovery.

The National Association of Realtors says sales of previously occupied homes fell 5.4 percent in June to a seasonally adjusted annual rate of 4.37 million homes. That’s the fewest since October.

Sales are up 4.5 percent from a year ago, evidence that the market is still recovering. But the annual sales pace is below the 6 million that economists consider healthy.

The number of first-time buyers, critical to a housing recovery, made up just 32 percent of sales. That’s down from 34 percent in May. In healthy markets, first-time buyers make up more than 40 percent of the market.