A powerhouse in manufacturing and exports, the world's second-largest economy has long extended extensive government support to domestic firms.

Critics abroad say the practice harms fair market competition.

The Organisation for Economic Cooperation and Development (OECD) said Monday that Chinese companies in 15 key industrial sectors received vastly more state support than their international competitors between 2005 and 2024.

Asked about the report on Wednesday, Chinese foreign ministry spokeswoman Mao Ning said that the country's "industrial subsidy policy adheres to the principles of openness, fairness and compliance".

"The competitive strengths of Chinese firms are not the result of subsidies, but rather highly market-oriented competition, continuous technological innovation, global expansion and the advantages of economies of scale brought about by a massive market," she said at a regular news conference.

The OECD said almost 60 percent of Chinese firms' global market share gains could be explained by the subsidies they received.

Chinese firms have built up huge market shares over 20 years in sectors such as solar panels, shipbuilding and steel, not because they are better than their US or European competitors but because of their unparallelled state support, it added.

But Mao said Wednesday that subsidies are "commonly used" around the world, calling on countries to comply with World Trade Organization rules.

"It is hoped that relevant international organisations will play a constructive role, not the opposite," she added.