BOSTON (AP) -- The median price of a single-family home in Massachusetts rose last month to its highest level in almost six years, two organizations that track the state's real estate market announced Tuesday.

The rise in median prices in June went hand in hand with a slight increase in sales when compared with the same month last year, according to The Warren Group and the Massachusetts Association of Realtors.

Median prices jumped last month to $350,000, a 9 percent increase from June 2012, according to the Boston-based Warren Group, a publisher of real estate data.

The Waltham-based Realtors association reported a nearly 7 percent year-over-year jump to $350,500. It was the ninth consecutive month of year-over-year price rises and the highest they have been since August 2007, both groups said.

Warren Group Chief Executive Timothy Warren Jr. said "aggressive bidding is driving up prices," but also issued a few words of caution.

"We don't want to see prices rise to the point where homeownership becomes unaffordable," he said.

The Realtors reported a 1.6 percent increase in sales of single-family homes last month, while The Warren Group reported a 1 percent jump.

The news wasn't quite so good in the condominium market. While median prices were up around 3 percent in June compared with the year-ago month, sales numbers were modest. The Warren Group reported a 3 percent decrease, while the Realtors reported an increase of less than 1 percent.