U.S. existing-home sales fell for the third straight month in June, as declines in the country's South and West exceeded sales gains in the Northeast and Midwest.

Meanwhile, the ongoing supply and demand imbalance helped push June's median sales price to a new all-time high, according to the latest report released by the National Association of Realtors (NAR) on Monday.

NAR said that total existing-home sales, which are completed transactions that include single-family homes, townhouses, condominiums and co-ops, decreased 0.6 percent to a seasonally adjusted annual rate of 5.38 million in June from a downwardly revised 5.41 million in May.

With last month's decline, sales are now 2.2 percent below a year ago.

"There continues to be a mismatch since the spring between the growing level of home buyer demand in most of the country in relation to the actual pace of home sales, which are declining," said Lawrence Yun, NAR's chief economist.

He added that the root cause was undoubtedly "the severe housing shortage" that is not releasing its grip on the nation's housing market.

The median existing-home price for all housing types in June was 276,900 U.S. dollars, surpassing last month as the new all-time high and up 5.2 percent from June 2017, which was 263,300 U.S. dollar.

Properties typically stayed on the market for 26 days in June, unchanged from the last three months and down from 28 days a year ago, according to NAR data, with fifty-eight percent of homes sold in June staying on the market for less than a month. Enditem