Homes sales edged down in June, coming off a six-year high in May.

The National Association of Realtors Pending Home Sales Index fell slightly in June, declining by 0.4%. The result sees home sales come off a May result that was the highest since December 2006.

NAR chief economist Lawrence Yun said the dip in home sales showed the impact rising home prices and interest rates are beginning to have on affordability, especially in already high-cost regions.

"Mortgage interest rates began to rise in May, taking some of the momentum out of contract activity in June. The persistent lack of inventory also is contributing to lower contract signings," Yun said.

In spite of the decline, home sales remain 10.9% higher than a year ago. The NAR said pending sales have now been above year-ago levels for 26 consecutive months, and Yun predicted that - though sales may continue to see slight declines - the housing market will continue to perform more strongly than in 2012.

"Closed sales may edge down a bit in the months ahead, but they'll stay above year-ago levels."