Fewer Americans bought homes in August, as investors retreated from real estate and first-time buyers remained scarce.

The National Association of Realtors says sales of existing homes fell 1.8 percent to a seasonally adjusted annual rate of 5.05 million. That snaps a four-month streak of gains. August sales are down from a July rate of 5.14 million, a figure that was revised slightly downward.

Much of the slowdown came from the exodus of investors, who had been buying properties in the aftermath of the housing bust and recession. Investors accounted for just 12 percent of August purchases, compared to 17 percent a year earlier.

Overall, the pace of home sales has dropped 5.3 percent year-over-year.

Rising prices through much of 2013 and weak income growth priced out many would-be buyers.