Sales of existing homes fell in June and are expected to keep sinking showing renewed turbulence in the housing market as the tax credit expires and unemployment remains high.

Sales fell 5.1 percent last month to a seasonally adjusted annual rate of 5.37 million, the National Association of Realtors said Thursday. Year-over-year sales were up 9.8 percent.

June sales still captured some buyers who availed of the popular $8,000 tax credit, which was initially due to expire on June 30 but was extended September.

"The supply of homes on the market is higher than we'd like to see," said NAR chief economist Lawrence Yun, adding that home prices have held up well despite the glut.

The national median existing-home price for all housing types was $183,700 in June, up 1% from a year ago, according to NAR.

As sales have slowed, the inventory of unsold homes on the market has risen 2.5 percent to nearly 4 million. At current sales pace, that is a nearly nine-month supply, the highest level since August. Considered healthy inventory level is about six-month supply.