NEW YORK — No. 2 home-improvement retailer Lowe's Cos. yesterday said second-quarter earnings fell 19 percent on weaker-than-expected sales, adding fresh fuel to doubts about the ability and willingness of consumers to lead the U.S. economy out of recession.

Lowe's shares and the broader market fell sharply as investors worried that consumers remain tight-fisted in their spending habits. A recovery in consumer spending is crucial for an economic recovery because it accounts for two-thirds of all U.S. economic activity.

The weak results added to economic worries from Friday, when an indicator of consumer sentiment fell significantly short of expectations for the first part of August.

Lowe's results were a stark contrast to the prior quarter, when the company said it saw fresh signs of a consumer resurgence. Yesterday's release cited continued consumer weakness.

The weak earnings combined with a narrowed full-year profit outlook to knock shares down $2.36, or 10.3 percent, to close at $20.47. It was the worst-performing stock in the S&P 500 Index in trading yesterday.

"Wavering consumer confidence, unseasonable weather in core markets, and restrained customer spending compared to last year's fiscal stimulus-aided results led to lower than expected sales in the second quarter," Robert A. Niblock, Lowe's chairman and CEO, said in a statement.

Lowe's said profit fell to $759 million, or 51 cents per share, from $938 million, or 64 cents per share, last year.

Revenue fell 5 percent to $13.84 billion from $14.51 billion last year. Analysts predicted a profit of 54 cents per share on revenue of $14.35 billion. Lowe's had forecast earnings of 51 cents to 55 cents per share.

Sales in stores open at least one year, a key retail metric known as same-store sales, fell 9.5 percent.

Lowe's, like much of the housing and home-improvement industry, has been battered by a weak real estate market, rising unemployment and weak consumer confidence.

Niblock said in an interview with The Associated Press that the second-quarter results likely do not signal a shift in consumer behavior. Rather, weather was unseasonably cool and wet in the Northeast and fiscal-stimulus checks a year ago aided sales more than the company expected, he said.

The company said it is scaling back expansion plans in 2010, opening 35 to 45 stores during the year. It said it is also taking a $48 million charge for canceling plans for opening about 80 new stores over the next few years.