American retailers posted the biggest sales decline on record last month, trailing estimates that were already reduced as the coldest April in a decade curbed sales of lightweight clothing.

Wal-Mart Stores Inc., the world’s largest retailer, said April sales fell 3.5% trailing its forecast for a decline of at most 2%. Sales at stores open at least a year dropped at Federated Department Stores Inc. and Gap Inc.

Temperatures dipped 5 degrees below normal in the Northeast, cutting into sales of shorts, and other spring apparel. The results may be further evidence that consumer spending, which accounts for twothirds of the economy, is slowing.

“The consumer isn’t dead but I don’t think they are itching to open their wallets,” an analyst at Brean Murray Carret & Co. in New York, Eric Beder, said.

Easter was eight days earlier than in 2006, shifting purchases for the season into March. Analysts said the declines were caused mainly by one-time events, and most retailers maintained their profit forecasts.

The Standard & Poor’s 500 Retailing Index of 30 companies declined 1.2% as of 4:15 p.m. New York time. It has risen 3.3% this year, compared with a 5.2% gain on the Standard & Poor’s 500 Index.

Shares of Wal-Mart slipped 18 cents to $47.75 in New York Stock Exchange composite trading. Federated dropped $1.72, or 3.9%, to $42.10 and Gap declined 15 cents to $18.28.

Sales at 53 American retail chains fell a combined 2.4%, the International Council of Shopping Centers said. The “ugly” decline was the largest since the New York-based trade group started keeping records in 1970, the chief economist from the International Council of Shopping Centers, Michael Niemira, said. The ICSC had forecast a “small dip” in April.

March sales climbed 5.9%, the biggest gain since April 2006, according to the New York-based ICSC. For March and April combined, rose 1.8%.

A record 80% of retailers missed analysts’s estimates in April, according to Retail Metrics Inc. Same-store sales are an industry benchmark used to measure the health of older stores.

Goldman Sachs Group Inc. said its index of April sales, which tracks about 30 retailers, fell 3%.

Last month was the coldest April since 1997 in America and the snowiest in more than 14 years, according to Weather Trends International, a Bethlehem, Penn.-based firm. Three-quarters of the country had temperatures that were lower than normal, the firm said.

“April sales results were a distortion,” an analyst at PNC Wealth Management in Philadelphia, Steven Baumgarten, said. “A lot of retailers planned for the weak April.” The firm manages $54 billion, including shares of Wal-Mart and J.C. Penney Co.

Yesterday’s results confirm that consumer spending has slowed down, Niemira said yesterday in an interview. American consumers’s confidence dropped to a seven-month low in April as concerns about fuel prices, inflation, and home values intensified, according to the Reuters/University of Michigan’s final index of sentiment released April 27.

The average price of a gallon of unleaded gasoline rose to $3.05 for the week ended May 7, the highest since September 2005, the U.S. Energy Department said. The National Association of Realtors this week lowered its projections for both new and existing home sales this year and said prices will decline.

Discounters’s sales fell 4.6% in April, the ICSC said. Wal-Mart said cooler weather hurt demand. Sales this month and in the second quarter may rise 1% to 2%, the Bentonville, Ark.-based company said yesterday.

Target Corp., the second-largest American discount chain, said April sales declined 6.1%, while analysts predicted a drop of 6.4%. The Minneapolis-based retailer said it was “on track” to meet its full-year financial goals.

American retailers plan to report May sales on June 7. The ICSC forecast an increase of 2% to 2.5%.