U.S. existing home sales fell less sharply than expected to a three-month low in June, though the supply of unsold homes rose to the highest in almost a year, an industry group said on Thursday.

Sales fell 5.1 percent to an annual unit rate of 5.37 million units, the National Association of Realtors said. Economists polled by Reuters had expected an 8.1 percent decline to a 5.18 million pace in June.

There were about 3.99 million homes for sale at the end of June, a level that would take about 8.9 months to deplete at the current sales pace. That's the highest monthly supply since August 2009.

Sales have risen 9.8 percent since June 2009.

NAR chief economist Lawrence Yun said he expected the inventory of homes to rise to higher than a 10-month supply in the coming months as the pace of sales for homes under contract has declined.

That increase in the inventory of unsold homes could push prices down if the higher supply remains unsold for a prolonged period.

The median home sales price in June was $183,700, a 1.0 percent increase from the prior year.