Sales at supermarkets open for at least one year fell 3.4 pct year-on-year in May to 1.16 trln yen, the Japan Chain Stores Association said. Sales were down for the fifth straight month, the association said. The figures are based on the combined sales of 87 supermarket chain operators running a total of 8,791 outlets. The data have been adjusted to facilitate comparison on a same-store basis. Including sales at stores newly opened during the past year, revenue declined 1.0 pct from a year earlier. The association said supermarket sales last month fell in all five product categories. Sales of food -- the largest category, accounting for 60.5 pct of overall revenue -- declined 1.6 pct from a year earlier. Sales of household products -- the second-largest category, accounting for 20.0 pct of overall revenue -- fell 2.2 pct. Sales of clothing -- the third-largest category, at 13.1 pct of the total -- were down 3.5 pct. Sales of miscellaneous goods -- the fourth-largest category, accounting for 5.9 pct -- were down 17.1 pct. Revenue from services -- accounting for 0.4 pct of the total -- were off 48.7 pct