The U.S. National Association of Realtors said Tuesday the housing slump will extend into 2008, reducing its home sales forecast for the ninth time this year.

Existing home sales will fall 8.6 percent in 2007, exceeding the 6.8 percent drop estimated a month ago, the Chicago-based trade group said in a statement.

New-home sales probably will decline 24 percent on top of an 18percent fall in 2006.

"There's been an unusual hit to home sales, starting in March when subprime problems emerged and more recently when problems spread to jumbo loans," Lawrence Yun, an economist for the group, said in the forecast.

Jumbo loans are those over the 417,000 dollars limit guaranteed by Fannie Mae and Freddie Mac and are typically given to borrowers with good credit.

New home sales will not sink to a bottom until the first quarter of 2008, the organization said.