NEW YORK (CNNMoney.com) -- Home prices posted their biggest drop on record in September while sales fell for the sixth month in a row, a real estate group said Wednesday - the latest signs that the housing market is still weakening.

The National Association of Realtors (NAR) said sales of existing homes fell to an annual pace of 6.18 million last month from 6.3 million in August, marking the sixth straight monthly decline in sales.

Economists surveyed by Briefing.com had forecast a rate of 6.25 million in the most recent period.

The median price of a home sold in September fell 2.2 percent to $220,000 from $225,000 a year ago. It was the biggest year-over-year drop since the trade group began tracking median home prices in 1968.

Month-to-month declines in home prices are not uncommon, but a year-over-year drop is a more serious sign of a slumping housing market.

The group's August sales report was the first in 11 years to show a year-over-year decline in the price of a typical home.

The median is the point at which half the homes sold cost more and half less.

One bright spot for the housing sector in the report was a decline in the number of homes on the market, which fell 2.4 percent to 3.75 million in September, giving the market a 7.3 month supply of homes at the current sales pace, which was unchanged from both August and July. But there are still more homes for sale in 2006 than there were last year.

Thomas Stevens, a realtor in Vienna, Va., and the president of the trade group, viewed that number as encouraging.

"The good news is that fewer new listings are coming online," Stevens said in a statement. "It appears we have passed a cyclical peak in terms of the number of homes on the market."

Because there were fewer homes on the market in 2005 and such a demand by buyers, Lawrence Yun, a senior economist with NAR, said that this probably will not be the last drop in median home prices the real estate sector sees this year.

"We'll see continuing weakness in home prices in the next few months before turning upward by spring of 2007," he said.

One other noteworthy item in the trade group's report was that the South was the only region nationwide to report an increase in existing home sales from last month, suggesting the region has been slightly more resilient to the recent downturn in the housing sector.

The real estate market and home building have cooled significantly since hitting records in 2005 - one of the key causes of a slowdown in the broader economy cited by the Federal Reserve at its last two meetings as a key reason not to raise interest rates. The central bank's latest decision on rates and view of the economy is due later Wednesday.

The slowdown has hurt profits and sales for the nation's major home builders, including Pulte Homes (up $0.73 to $32.49, Charts), Centex (up $1.35 to $53.74, Charts) D.R. Horton (up $0.58 to $24.16, Charts), Lennar (up $0.92 to $47.26, Charts), K.B. Home (up $1.22 to $45.54, Charts) and Toll Brothers (up $0.88 to $30.48, Charts). Tuesday afternoon Centex, the nation's No. 2 home builder in terms of revenue, became the latest to cut its sales forecast for the current period and rest of its fiscal year that runs through March.

The government will report on new home sales for September on Thursday -considered more of a leading indicator of the market since it's based on sales when contracts are signed, not on closings, which are used for existing home sales and usually come months later.

Housing starts fall, confusion rises

More on real estate