Winn-Dixie Stores Inc posted a wider quarterly loss and gave a weak 2010 outlook as recession-hit consumers shopped for lesser number of items on every visit to its stores, sending the supermarket chain's shares down 13 percent.

Same store sales -- a key measure of retail health -- decreased 1.5 percentage for the first quarter compared with the year-ago period.

The company also said sales were hurt as consumers shifted toward generic pharmaceuticals and an absence of storm-related sales that it saw last year.

Adjusting for storm-related sales and the shift from branded pharmaceuticals to cheaper generics, same store sales were flat, the company said in a statement.

Wal-Mart Stores Inc recently put considerable pressure on grocery stores and discount retailers, when it announced its plans to cut prices each week during this holiday season.

Last week, Winn-Dixie's larger rival Supervalu Inc slashed its quarterly dividend and gave a weak full-year profit forecast, hit by a fierce price war among food sellers.

Winn-Dixie cut its full-year 2010 earnings before interest, taxes, depreciation and amortization (EBITDA) outlook to between $140 million and $160 million.

For the latest first quarter, the company posted a loss of $8.1 million, or 15 cents a share, compared with a loss of $2.3 million, or 4 cents a share, a year ago.

Total sales fell 2 percent to $1.64 billion.

The economic climate continued to impede our growth during the quarter and caused our adjusted EBITDA to fall below last year's levels, Chief Executive Peter Lynch said in a statement.

However, he added that transaction count was flat in the current quarter.

Adjusted EBITDA in the first quarter of fiscal 2009 included an estimated benefit of $2.7 million due to storm-related sales net of storm-related inventory losses and other costs, the company said.

Shares of the company were down 13 percent in trading after the bell. They had closed at $13.33 Monday on Nasdaq.

(Reporting by Vidya Lakshmi in Bangalore; Editing by Unnikrishnan Nair, Saumyadeb Chakrabarty)