Retail sales in South Korea advanced 9.5 percent on-year in September amid the strong performance of online platforms coupled with the Chuseok holiday, data showed Monday.

The combined sales of 25 major offline and online retailers came to 15.3 trillion won ($11.2 billion) last month, compared with 13.9 trillion won a year earlier, according to the data compiled by the Ministry of Trade, Industry and Energy.

Online platforms saw their sales advance 12 percent to 7.46 trillion won on the back of food items and cosmetic products.

Sales from offline retailers also jumped 7.2 percent on-year to 7.8 trillion won on the back of the Chuseok fall harvest holiday that began in late September, the data also showed.

Among offline stores, department stores saw their sales move up 3.1 percent over the period following the strong demand for food, with the sector rising 35.1 percent.

Supermarkets' sales also gained 10 percent on the back of food items, although the weaker demand for home appliances amid inflation limited the overall growth.

Online platforms, meanwhile, accounted for 48.9 percent of total sales in September, up from 47.8 percent a year earlier, the ministry said. (Yonhap)