US Steel Corporation and Nucor Corporation have said in separate motions in federal trade court that US Department of Commerce failed to follow its own rules when assessing anti dumping duties on South Korean steelmakers.

The steelmakers, which dispute the anti dumping duties assessed on a Korean rival Union Steel, asked the court for a judgment on the agency record.

The companies said that the DOC failed to properly valuate inputs from a Union affiliate and violated its own rules as to what should be considered negligible.

The DOC undertook an administrative review of anti-dumping duties on corrosion resistant carbon steel products from Korea, including Union's, in September 2007 and published its final results in March 2009. In the review process, the DOC made its input valuation while ignoring steel substrate inputs from several Union affiliates, saying in their unpublished memorandum that those inputs they amounted to an insignificant amount of Union's total inputs.

US Steel filed suit against the DOC in April, and was joined by plaintiff intervenor Nucor in June.

In the suit and recent motion for judgment on the administrative record, US Steel asks the court to hold that the complained about valuations are not supported by substantial evidence and are otherwise not in accordance with law. It said that "Commerce's decision not to make the adjustment because it was allegedly insignificant cannot stand. The undisputed facts show that Commerce's calculations were repeatedly incorrect and often grossly understated the magnitude of the adjustment."

In its motion, Nucor largely echoed US Steel's arguments, but added an additional request: Union's tariff should be collapsed into that of fellow Korean steelmaker POSCO, since the two companies have sufficiently intermingled operations to warrant it.

Nucor said that "The department's goal in collapsing two companies is forward looking and does not require actual manipulation of price or production during the period of review. Here, there is compelling affirmative evidence of intertwined operations."