Members of the cartel set prices and divided up the market, while restricting imports, GVH said. It added that the illegal practices drove up farmers' input prices and may have fed into consumer food prices.

Of the nine companies involved in the cartel, two admitted wrongdoing and cooperated with GVH. GVH reduced the fine of one of those companies and waived the fine of the other.

Six of the companies that were fined in full are members of the Nitrogénművek group. The others are Hőgyészi Agrokémiai and Cargill Magyarország.

Nitrogénművek/Bige Group told MTI that it learned of the GVH decision on Friday and is in the process of evaluating it, but would "certainly challenge it in court". Nitrogénművek/Bige Group added that the timing of the fine, "of an unprecedented scale", on an industry highly exposed to the European energy crisis "raises many questions".