ArcelorMittal files patent infringement suit against Severstal and Nisshin Steel Holdings

ArcelorMittal, the world's biggest steelmaker, has sued the US units of Russian steelmaker OAO Severstal and Japan's Nisshin Steel Holdings Co for infringing its patent on metal used in auto parts.

ArcelorMittal's US subsidiary ArcelorMittal USA has filed the lawsuit in the US District Court in Wilmington, Delaware against Michigan-based Severstal Dearborn and West Virginia-based Wheeling-Nisshin.

The move comes barely a month after ArcelorMittal lost an aluminised boron steel patent infringement suit against Ohio-based AK Steel Holding Corp.

ArcelorMittal, which claims to have an ''exclusive right and license'' under the patent, is seeking unspecified damages from Severstal and Wheeling-Nisshin after a jury trial.

In an email answer to a Bloomberg query, Katya Pruett, a Severstal spokeswoman, said, ''For the past three years, Severstal has successfully defended itself'' against ArcelorMittal claims, and ''it will continue to successfully defend itself against this most recent complaint.''