Flour products are displayed at a grocery store in Seoul, April 5. Yonhap

Seven flour makers were fined a combined 671 billion won ($444 million) for colluding on prices and supply volumes for nearly six years, the Fair Trade Commission (FTC) said Wednesday, marking the largest cartel penalty ever imposed in Korea.

The companies are Daehan Flour Mills, CJ CheilJedang, Sajo DongA One, Samyang, Daesun Flour Mills, Samhwa Flour Mills and Hantop.

They engaged in unfair price-fixing activities between November 2019 and October 2025, targeting their major business-to-business (B2B) clients, such as noodle, instant noodles, confectionery and bakery makers, according to the FTC investigation.

Collectively, the seven firms accounted for 87.7 percent of the nation’s B2B flour-based sales in 2024.