The latest comments from the world's biggest retailer reflects accounting for some Brazil-related charges and other items.
Chief Financial Officer Charles Holley said in a statement that these additional items were not anticipated when Wal-Mart previously provided its forecasts.
Shares of the Bentonville, Arkansas, company fell 70 cents to USD 74.05 in premarket trading about 45 minutes ahead of the market opening.
Wal-Mart Stores Inc also revised its fourth-quarter guidance for a key sales metric.
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The chain previously expected the key sales figure would be relatively flat at its namesake locations in the US and that it would be between flat and 2 per cent at Sam's Club.
Sales at stores open at least a year is a closely-watched indicator of a retailer's health. It excludes results from stores recently opened or closed that can distort year-to-year comparisons.
Holley said that the sales were hurt by eight winter storms that resulted in some store closings. He added that Sam's Club was hurt by weather throughout the quarter.