Ito-Yokado Co., Japan's largest retailer, on Thursday became the latest chain to report dismal first-half results due to the cool summer.

The group's supermarkets, including subsidiary stores, saw operating profit drop 71.2 percent to 4.8 billion yen and revenue decline 2.1 percent to 826.5 billion yen for the six-month period ending Aug. 31.

"These were the worst results for a first half," Ito-Yokado President Sakae Isaka said.