NEW YORK — Crumbling consumer confidence and slumping home sales could prove to be a bad combination for retailers and for the broader economy going into the holiday shopping season, if the labor market contracts further and chokes off spending, economic data showed yesterday.

But markets took some heart from the warning signs, hoping that they would goad the Federal Reserve to further reduce interest rates.

Worries about jobs and the economy flared in September, driving a key barometer of consumer sentiment to its lowest level in nearly two years, a private research group said.

The bad news was compounded by a report from the National Association of Realtors that sales of existing homes declined for a sixth straight month in August, pushing activity to the lowest point in five years. The Realtors showed a rise in median home prices, but a separate report done by S&P/Case-Shiller, said home prices fell 3.9 percent in July in its 20-city index. Economists said that decline was probably a better reflection of where the market stands now.

The New York-based Conference Board said its Consumer Confidence Index fell to 99.8, an almost six-point drop from the revised 105.6 in August. The reading was below the 104.5 that analysts had expected.

It marked its lowest level since a 98.3 reading in November 2005, when gas and oil prices soared after hurricanes Katrina and Rita devastated the Gulf Coast.

"Weaker business conditions combined with a less-favorable job market continue to cast a cloud over consumers and heighten their sense of uncertainty and concern," said Lynn Franco, director of The Conference Board Consumer Research Center, in a statement. "Looking ahead, little economic improvement is expected, and with the holiday season around the corner, this is not welcome news."

The Present Situation Index, which measures how shoppers feel now about the economy, declined to 121.7 from 130.1 in August. The Expectations Index, which measures shoppers' outlook over the next six months, declined to 85.2 from 89.2.

Economists closely monitor confidence because consumer spending accounts for two-thirds of U.S. economic activity.

The National Association of Realtors reported yesterday that sales of existing single-family homes dropped 4.3 percent in August, compared to July. Sales at a seasonally adjusted annual rate dropped to 5.5 million units, the slowest pace since August 2002.

The S&P/Case-Shiller report, also released yesterday, showed that the decline in U.S. home prices accelerated nationwide in July, posting the steepest drop in 16 years. The index of 10 U.S. cities fell 4.5 percent in July from a year ago. That was the biggest drop since July 1991.

Yesterday's reports showing eroding consumer confidence and a further weakening of housing do not bode well for retailers, who already are bracing for a challenging holiday season. Merchants have seen spending slow all year amid falling home prices and higher gas and food bills. Financial turmoil in August and escalating problems in the credit market have made economists and retailers more nervous about the prospects for a decent holiday shopping season.

Such anxiety is further heightened by a weakened outlook for September sales.

Based on a weak weekly sales report, The International Council of Shopping Centers yesterday trimmed its September same-store sales growth estimates to between 2.0 percent and 2.5 percent, from the previous 2.5 percent. Same-store sales are sales at stores open at least a year and are considered a key indicator of a retailer's health.