A
US appeals court ruled Tuesday that three infringement lawsuits involving a lightweight steel patent should not have been canceled outright. The lawsuit was filed in 2010 by
ArcelorMittal against
AK Steel,
Severstal Dearborn and Wheeling-Nisshin.
According to the ruling, two claims of the company's reissued patent have been revived, although the judge affirmed the
US district court’s ruling that invalidating the rest.