NEW YORK (CNNMoney.com) -- The slowdown in the real estate market ain't over, according to an industry report showing a slowdown in sales that's putting downward pressure on prices.

The National Association of Realtors said Monday that existing home sales fell to an annual pace of 6.30 million in August from a revised July reading of a 6.33 million rate.

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While that's down just a bit from July, the pace of sales is down 12.6 percent from a year earlier.

Economists surveyed by Briefing.com had forecast that sales would slow to a 6.25 million pace in August.

The inventory of homes on the market in August was 3.9 million, up 37 percent from the same time a year ago. That gave the market a 7.5 month supply of homes, a nearly 60 percent jump from a year earlier.

The median and average sales prices also both fell about 2 percent from year-earlier levels. While month-over-month declines in prices are not uncommon, year-over-year decreases in prices is a more serious sign of a slumping housing market.

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