South Korea's major department stores and discount chains reported a drop in sales in August compared to the year before, mainly due to a shift in the date of the Chuseok holiday, the government said Tuesday.

The combined sales of three department store chains -- Hyundai, Lotte and Shinsegae -- backtracked 7.6 percent on-year last month, according to the Ministry of Trade, Industry and Energy.

The total sales of three major discount outlet chains -- E-Mart, Homeplus and Lotte Mart -- also fell 6.5 percent on-year in August,

The drops follow generally weak sales in the preceding months brought on by the Middle East Respiratory Syndrome outbreak that killed 36 people in South Korea. The respiratory disease infected a total of 186 people, but no new cases have been reported since July 4.

"Last month's numbers are mostly the result of Chuseok falling in late September this year, while in 2014, the Korean Thanksgiving holiday took place in early September and contributed to a spike in sales in August," the ministry said. The three-day traditional holiday is celebrated according to the lunar calendar and therefore the date changes from year to year. The weeks prior to Chuseok usually witness a rise in consumption as people buy gifts for family and friends, and prepare special dishes.

The ministry said a rebound in sales is expected for September of this year.

Sales at convenience stores, meanwhile, continued to grow by a large margin, spiking 34.3 percent on-year last month, helped by the rise in the sales of cigarettes.

Sales at the so-called super supermarkets, mostly run by large retailers, slipped 1.7 percent on-year, according to the latest data. (Yonhap)