Home-sale agreements in the nine-county Indianapolis area plummeted more than 27 percent in July compared to the same month of 2009, according to a report released Wednesday by residential real estate firm F.C. Tucker Co.

The decline marked the third straight month that home sales have slumped in central Indiana following three straight months of improving sales activity spurred by generous federal tax credits.

Pending home sales dropped from 2,351 in July 2009 to 1,707 last month, a decline of 27.4 percent. Pending sales were down 30 percent in June and 32 percent in May.

Pending home sales account for sales agreements, not sales that have closed. Year-to-date, sales agreements are off 2 percent from the same seven months of 2009.

In Marion County, July sales agreements fell 32.5 percent compared to the previous year, from 1,100 to 743. Pending sales dropped 25.6 percent in Hamilton County, from 496 to 369, and 32.3 percent in Hendricks County, from 198 to 134.

Johnson County saw the area’s smallest decline, as pending sales dropped 11.9 percent, from 177 to 156.

On a positive note, the average price of homes sold in the area in July was up 9.8 percent, from $146,155 in July 2009 to $160,496 in July 2010. Home prices were up 18.2 percent in Hamilton County, to $277,966, and 6.7 percent in Marion County, to $119,786.

Home inventory was up 5.8 percent in July from a year ago, with 17,276 homes listed in the nine-county area.