Major steel-producing nations like Japan, Brazil and South Korea have long complained about US efforts to stem the flow of cheap imports, but the Clinton administration says that measures were needed to protect US producers from steel dumped in the United States at below fair market value.

"Nobody is going to argue that the US market is not the most open market in the world, especially in steel," said US Commerce Under Secretary for International Trade Robert LaRussa, who called the study "totally ridiculous and absurd."

Written by lawyers for foreign producers and released by the American Institute for International Steel, the study claims that US steel makers have benefited from more than $21 billion in federal, state and local subsidies over 30 years.

Since the late 1960s, the study says, an assortment of US trade restraints and price quotas have created a "protected, overpriced US steel market" that has cost American consumers an alleged $90 billion to $150 billion.

"American consumers and tax payers have paid a high price to protect an antiquated industry that refuses to modernise and compete fairly in the open global marketplace," said Horst Buelte, chairman of the Washington-based American Institute for International Steel, which represents importers and exporters.

The study was written by attorneys from Willkie Farr & Gallagher who represent foreign steel producers and US Importers in international trade disputes.

LaRusso called the study "biased," and said the White House was finalising its own report analysing steel policies, which is expected to show how US markets remained open despite a flood of imports from countries including Japan. "Let's face it, if anybody wants to take a look at the impact of protectionist practices on consumers, the first place to look is Japan," LaRusso said. Under pressure from US steel makers and labour unions, the Clinton administration has imposed punitive duties on a wide range of steel imports, alleging they were dumped in the US market at unfair prices.

Earlier this month, the US International Trade Commission cleared the way for duties as high as 65 percent on Japanese structural beam imports. In February, Clinton slapped tariffs on steel line pipe and wire rod imports, outraging foreign producers. In response, South Korea this week launched a World Trade Organisation (WTO) case against the United States, arguing that safeguard measures limiting line pipe imports violated open trading rules.