Mining giants Rio Tinto, BHP Billiton and Vale’s plans to raise the price of their products by up to 90% could mean hundreds of billions of yuan in losses for Chinese steel makers.

According to the China Iron and Steel Association (Cisa), Chinese steel manufacturers, which are already facing great challenge this year, will have to pay heavy additional costs, if the price hikes are implemented.

Initially, Rio Tinto raised prices by 40%, followed by BHP Billiton by 50% in February and recently Vale by 90%.

CISA secretary-general Shan Shanghua said the massive increase in steel production had caused a tense relationship between supply and demand, according to

“The three giants, Vale, Rio Tinto, and BHP Billiton, account for 70% of the world’s sea-borne traded iron ore. They are making supernormal profits by continuing to raise prices,” Shanghua said.

Eurofer, the European steel industry association, has also opposed the intention of iron ore producers to raise prices.