Salt Lake County's apartment vacancy rate was 6.8 percent in the third quarter, up from 4.3 percent a year earlier, according to a CB Richard Ellis report released this week.

In communities with more than 100 units, the average apartment rental rate in the county was $794 in the third quarter, down 3.2 percent compared to $820 in the same quarter a year earlier. The highest rent on the average two-bedroom unit was found in the northeast submarket at $932 per month, and the lowest average two-bedroom rate was found in the northwest submarket at $765 per month.

The report tracked 131 apartment communities totaling 29,679 units.

Seth Rossow, multi-family investment specialist at CB Richard Ellis, said the apartment vacancy rate appears to be stabilizing, but the rate will rise in 2010 as new apartment buildings are completed.

Thirteen apartment projects with a combined 3,103 units are under construction in Salt Lake County. In the past 12 months, eight communities having a total of 1,713 units have been completed.