With Wal-Mart Stores Inc. (WMT) dropping monthly same-store-sales reports, investors are losing a valuable barometer and may also expect other retailers to follow suit in what could be a sea change in the way the industry disseminates information.

Wal-Mart's move "is a loss of a very important indicator and put a laser on the issue," said Peter Brown, vice chairman of consulting firm Kurt Salmon Associates. "They are the best gauge of what is going on with general consumer spending in America."

In tandem with issuing better-than-expected April same-store sales figures on Thursday, Wal-Mart said it was dispensing with the monthly report it has issued since 1979. The move will better align investors with Wal-Mart's own long-term approach to business and also cut volatility caused by holiday shifts, said Chief Financial Officer Tom Schoewe in a statement.

The company will now issue forecasts for the 13 weeks that roughly track its quarterly reporting periods.

Wal-Mart is not the first retailer to stop issuing monthly sales reports. Over the past year, about a half dozen retailers have done so, but they are mainly specialty retailers like AnnTaylor Stores Corp. (ANN), Guess Inc. (GES), Bebe Stores Inc. (BEBE), Cache Inc. (CACH) and Pacific Sunwear of California Inc. (PSUN). Analysts say many of the stores acted because their comparable-store-sales were deteriorating and it is also more of a cost drain on them compared to better-capitalized large retailers.

Macy's Inc. (M), among the biggest retailers in the nation, stopped dispensing same-store-sales figures in February of 2008 but started up again the following October.

No other large retailers have yet given indications they will follow in Wal-Mart's footsteps, but it may just be a matter of time, Brown said.

Volatility can certainly result when a retailer misses expectations. The biggest case in point on Thursday is Hot Topic (HOTT). The teen retailer did a lot better than most others in the industry by reporting a sales gain of 3.1%. But the advance was well below the 7% analysts expected and the stock is down 22% to $9.65.

There are retailers that may not want to keep bombarding investors with bad news. Limited (LTD) has now posted 20 consecutive months of same-store sales declines, according to Thomson Reuters. J.C. Penney Co. (JCP) and Gap Inc. (GPS) have both logged 17 straight monthly declines. Kohl's Corp. (KSS), Saks Inc. (SKS) and Stage Stores Inc. (SSI) all have 10 drops in a row. Abercrombie & Fitch Inc. (ANF), which has stuck largely to a no-promotion approach, has notched nine double-digit percentage sales declines in a row, Thomson Reuters said.

"It makes perfect sense for Wal-Mart to stop monthly same-store sales reports," said Brian Sozzi, equity retail analyst at Wall Street Strategies. "And I would expect others to start falling under the umbrella."

Sozzi feels the moves could lead to lesser sharp moves by stocks and help their performance in the long run as investors become more focused on trends in the companies' business, rather than sporadic shifts.

It does mean that investors will have to work a little harder, though, Sozzi said. "There will be a bit less easily attainable information out there, but a little extra footwork on investors' parts will help make up for it."

Wal-Mart's move on Thursday followed its decision in February to give comparable store guidance on a quarterly, rather than monthly, basis.

The company, when it posts results next Thursday, will provide a forecast for comp-store sales for the second quarter, which runs from May 2 through July 31, 2009. That period's same-store-sales figures will be released when Wal-Mart announces second quarter earnings on Aug. 13.

Thomson Reuters plans to keep with trend by starting this summer to issue quarterly same-store-sales reports, while continuing its monthly releases.

-By Karen Talley, Dow Jones Newswires, 201-938-5106; karen.talley@dowjones.com