The National Association of Realtors said the index that keeps track of contracts of intention rose 0.3 percent in the month after after sliding away from the highest level in more than two years in August.
Although gains were slight, the index has shown year-over-year improvements for 17 consecutive months. In step with that data, the index in August is 14.5 percent higher than the 86.9 posting from September 2011.
"Home contract activity remains at an elevated level in contrast with recent years, but currently appears to be bouncing around in a narrow range," Lawrence Yun, NAR's chief economist, said in a statement.
NAR said the pending home sales index rose 1.4 percent in the Northeast to 79.3.
The index fell 5.8 percent in the Midwest to 89.5. In the South it rose 1 percent to 111.5. In the West, the index rose 4.3 percent to 106.9.
NAR's monthly forecast was increased slightly in September.
NAR forecast existing home sales to climb 9 percent to 5.1 million in 2013.
The last report predicted a rise of 8 percent to nearly 5.02 million next year.