The Ocean State’s single-family house listings in August grew as fewer buyers signed contracts to purchase and the average selling time during the summer stretched to 82 days, the Rhode Island Association of Realtors reported.

The statewide median price of a single-family house during June, July and August fell 3.2 percent, to $283,750, the report said, compared with $293,000 during the same period last year. The number of buyers who signed purchase-and-sales agreements in August declined 9.5 percent, to 863 contracts, down from 954 in the same month last year, the association reported. (The group recently began reporting sales under contract on a monthly basis to provide a “more current predictor” of sales trends, said the association’s spokeswoman, Kerry Park.)

The number of single-family houses on the Statewide Multiple Listing Service during the last week of August rose 6.2 percent from a year earlier, to 6,874, which represents about a 10-month supply. “Homebuyers’ confidence is weak despite solid gains in job growth, a stable local economy and continued low interest rates,” the Realtors association’s president, Cecil Cohen, said in a statement. “It’s a great time to buy or sell a home, but the subprime mortgage scare and other negative reports seem to be making people hesitant.”

The Rhode Island association also released an analysis of the Providence market conducted by the National Association of Realtors, which describes the recent price declines locally as “negligible” and predicts an upturn in the market.

The “price analysis” by the national group said that costs of houses in the Providence metro area — which includes Fall River and New Bedford — remained essentially unchanged during the second quarter of this year.

The national association forecasts that those prices will climb 2.5 percent this year, and 7.3 percent next year — if mortgage rates remain “relatively stable at around 6.5 percent over the next two years.”

“Despite some media reports of the worst housing market conditions since the early 1990s or since the Great Depression, the recent house-price declines have been negligible at the local level,” the national association report states.

The group also reported that Rhode Island’s foreclosure rate on conventional home loans remains below the national average, but the foreclosure rate for subprime loans, given to borrowers with blemished credit, “soared in 2005” above the national average. (The 2006 loan data is not yet available.)

Rhode Island’s job growth — which is running about 1 percent a year — has created more “potential homebuyers,” the national association reported. The relationship between jobs and house sales has historically been 1 to 2, or one new homeowner for every two new jobs created, the report said. During the 12-month period ending in July, payroll jobs had grown by 3,500.

The job gains “should provide underlying support for housing in this small-sized state,” the national association reported. “Such conditions are favorable for potential home-price growth.”

larditi@projo.com