SAN DIEGO — The real estate tracking firm DataQuick says the median price for homes in the nine-county San Francisco Bay Area reached $555,000 in June, an increase of 6.9 percent over the previous month.

DataQuick said Thursday that the rise was the result of disappearing distress sales, an improving economy and mortgage rates remaining low.

However, the number of homes sold dropped 7.5 percent to 7,897 in June. DataQuick attributes the decrease to the number of homes for sale falling short of demand and an easing of purchases by cash and investor buyers.

The real estate information service says last month's sales were 20.9 percent below the June average of 9,993 sales.