1 percent in September from a year earlier to 136.6 billion yen for the seventh consecutive monthly decline.
The Japan Department Stores Association said Friday that it was the steepest fall in three months, mainly due to sluggish sales of autumn clothes amid the lingering summer heat in the first half of the reporting month as well as unfavorable weather conditions, including a typhoon, in its latter half.
The association's preliminary report also cited falling demand from corporate customers.
Sales of clothing, the largest commodity sector, fell 10.9 percent to 49.93 billion yen. The scope of the fall was sharper than the 6.9 percent decline in August.
Sales of food, the second largest, dropped 0.9 percent to 26.16 billion yen for the seventh consecutive monthly decrease, the association said.
Sundry goods, including jewelry, cosmetics and stationery, dipped 1.3 percent to 24.19 billion yen, it said.
Sales of personal goods, including shoes and bags, fell 1.9 percent to 18.63 billion yen for the first fall in three months.