Dec. 23 (Bloomberg) -- Purchases at U.S. retailers fell last week as recession fears deterred shoppers from spending in the closing days of what may be the worst holiday sales season in four decades.

Sales at stores open at least a year declined 0.6 percent in the seven days through Dec. 20 from a year earlier, the International Council of Shopping Centers and Goldman Sachs Group Inc., said today in a joint statement.

The council cut its forecast for December, saying sales may fall 1 percent “or slightly more” from a year earlier. Previously, it had projected same-store sales for the month to rise as much as 1 percent or remain unchanged.

“There have been a few busy days and busy spots, but this has been nothing like a normal holiday season,” Patricia Edwards, a retail analyst and the founder of Seattle-based Storehouse Partners LLC, told Bloomberg Radio yesterday.

U.S. shoppers grappled with a recession, tightening credit and the loss of 1.91 million jobs through November. Retailers responded with steepened markdowns, which may erode profit margins in the fourth quarter, the most important of the year for retailers.

“This year especially, I think I have to be more careful,” said Magaly Torrez, 30, while shopping Dec. 20 at the Atlantic Terminal mall in Brooklyn, New York. “We have to buy just the necessities for the house and the kids.” The mother of two said she’ll shop for essentials at the after-Christmas sales “if we have any money left.”

ICSC has estimated that in November and December, sales may decline as much as 1 percent. That would be largest drop since at least 1969, when the New York-based trade group starting tracking data.

Some investors consider comparable-store sales the best measure of results because they exclude the effect of location openings and closings in the past year.

To contact the reporter on this story: Heather Burke in New York at hburke2@bloomberg.net.

Last Updated: December 23, 2008 07:46 EST