Existing-home prices continued to show gains, but sales fell in June with tight supplies of affordable homes limiting first-time buyers, according to the National Association of Realtors.

Total existing-home sales, which are completed transactions that include single-family homes, townhomes, condominiums and co-ops, declined 5.4 percent to a seasonally adjusted annual rate of 4.37 million in June from an upwardly revised 4.62 million in May, but are 4.5 percent higher than the 4.18 million-unit level in June 2011.

Lawrence Yun, NAR chief economist, said the bigger story is lower inventory and the recovery in home prices.

"Despite the frictions related to obtaining mortgages, buyer interest remains solid. But inventory continues to shrink and that is limiting buying opportunities. This, in turn, is pushing up home prices in many markets," he said. "The price improvement also results from fewer distressed homes in the sales mix."

According to Freddie Mac, the national average commitment rate for a 30-year, conventional, fixed-rate mortgage fell to a record low 3.68 percent in June from 3.80 percent in May; the rate was 4.51 percent in June 2011; recordkeeping began in 1971.

The national median existing-home price for all housing types was $189,400 in June, up 7.9 percent from a year ago. This marks four back-to-back monthly price increases from a year earlier, which last occurred in February to May of 2006. June's gain was the strongest since February 2006 when the median price rose 8.7 percent from a year prior.

Distressed homes -- foreclosures and short sales sold at deep discounts -- accounted for 25 percent of June sales (13 percent were foreclosures and 12 percent were short sales), unchanged from May but down from 30 percent in June 2011. Foreclosures sold for an average discount of 18 percent below market value in June, while short sales were discounted 15 percent.

"The distressed portion of the market will further diminish because the number of seriously delinquent mortgages has been falling," said Yun.

NAR President Moe Veissi, broker-owner of Veissi & Associates Inc., in Miami, said there's been a steady growth in buyer interest.

"Buyer traffic has virtually doubled from last fall, while seller traffic has risen only modestly," he said. "The very favorable market conditions are helping to unleash a pent-up demand, which is why housing supplies have tightened and are supporting growth in home prices. Nonetheless, incorrectly priced homes will not attract buyers."

Total housing inventory at the end June fell another 3.2 percent to 2.39 million existing homes available for sale, which represents a 6.6-month supply at the current sales pace, up from a 6.4-month supply in May. Listed inventory is 24.4 percent below a year ago when there was a 9.1-month supply.

First-time buyers accounted for 32 percent of purchasers in June, compared with 34 percent in May and 31 percent in June 2011.

"A healthy market share of first-time buyers would be about 40 percent, so these figures show that tight inventory in the lower price ranges, along with unnecessarily tight credit standards, are holding back entry level activity," Yun said.

All-cash sales edged up to 29 percent of transactions in June from 28 percent in May; they were 29 percent in June 2011. Investors, who account for the bulk of cash sales, purchased 19 percent of homes in June, up from 17 percent in May; they were 19 percent in June 2011.

Single-family home sales declined 5.1 percent to a seasonally adjusted annual rate of 3.9 million in June from 4.11 million in May, but are 4.8 percent above the 3.72 million-unit pace in June 2011. The median existing single-family home price was $190,100 in June, up 8 percent from a year ago.

Existing condominium and co-op sales fell 7.8 percent to a seasonally adjusted annual rate of 470,000 in June from 510,000 in May, but are 2.2 percent higher than the 460,000-unit level a year ago. The median existing condo price was $183,200 in June, which is 6.9 percent above June 2011.

Regionally, existing-home sales in the Northeast dropped 11.5 percent to an annual pace of 540,000 in June but are 1.9 percent above June 2011. The median price in the Northeast was $253,700, down 1.8 percent from a year ago.

Existing-home sales in the Midwest slipped 1.9 percent in June to a level of 1.02 million but are 14.6 percent higher than a year ago. The median price in the Midwest was $157,600, up 8.4 percent from June 2011.

In the South, existing-home sales declined 4.4 percent to an annual pace of 1.73 million in June but are 5.5 percent above June 2011. The median price in the South was $165,000, up 6.6 percent from a year ago.

Existing-home sales in the West fell 6.9 percent to an annual level of 1.08 million in June and are 3.6 percent below a year ago. The median price in the West was $233,300, up 13.3 percent from May 2011. Given tight supply in both the low and middle price ranges in this region, sales in the West are stronger in the higher price ranges.