A worker at a steel company in Lianyungang, Jiangsu province, in January 2015. [Photo/China Daily]

China will safeguard the interests of its steel producers by appealing to the World Trade Organization after the United States launched an investigation of Chinese companies for alleged price-fixing, the Ministry of Commerce said on Friday.

The ministry said the country was resolutely opposed to the US decision and would encourage its companies to legally defend their interests.

The US International Trade Commission said on Thursday that it would investigate a complaint by Pittsburgh-based US Steel Corp, which claimed that Chinese steelmakers and distributors conspired to fix prices, stole trade secrets via computer hacking and misrepresented the origin of their exports to the US.

In its complaint, US Steel Corp is seeking to bar nearly all imports from China's largest steelmakers.

Trade remedy measures recently taken by the US constitute trade protectionism, and they will disrupt trade and not solve the US steel industry's problems, said a statement by the ministry's Trade Remedy and Investigation Bureau.

It said current steel industry woes were global challenges and that a solution will require coordinated efforts by the countries concerned.

The US investigation would target 40 Chinese steel producers and distribution subsidiaries, including Baosteel Group, Hebei Iron & Steel Group Co, Wuhan Iron & Steel Co and Anshan Iron & Steel Group Co.

Shen Yan, head of the legal affairs department at Shanghai-based Baosteel, said he was shocked and angered by the US move, which he said is against WTO rules.

"The company will pay close attention to the case and support the Chinese government to take all necessary measures to ensure the rights of Chinese steel companies," said Shen.

Sun Jin, director of the international publicity office of Wuhan Iron & Steel, said he was baffled by the US decision, because steel products involved in this case are products manufactured by Chinese companies for many years.

Meanwhile, the US government imposed on Wednesday anti-dumping and anti-subsidy duties of up to 450 percent on exports of corrosion-resistant steel products from China.

The European Union also launched an anti-subsidy investigation this month into imports of Chinese hot-rolled flat steel, the subject of an anti-dumping probe since February.

Liu Zhenjiang, secretary-general of the Beijing-based China Iron and Steel Association, said the US recently has taken frequent trade remedy measures against foreign steel products without prudence, which will not help solve problems faced by US steel companies.

"Excessive trade protection is the primary cause that results in the operation loss of the US steel industry," said Liu.

Du Juan and Wang Ying contributed to this story.