December 08, 2015
A Delaware federal judge on Friday invalidated an ArcelorMittal SA patent on a type of steel asserted against AK Steel Corp. and others, rejecting ArcelorMittal's argument that two claims that were reissued during an earlier appeal created genuine issues of material fact.
October 29, 2013
A Delaware federal judge on Friday dismissed an infringement suit facing AK Steel Corp. after declaring ArcelorMittal SA's patent covering a form of specialized steel invalid, saying the company illegally broadened the claims when it obtained a reissue of the patent.
August 25, 2011
A Delaware federal judge on Thursday refused to overturn a jury verdict that found invalid an ArcelorMittal SA patent on steel used in car making and cleared defendant AK Steel Corp.
January 18, 2011
A federal jury has cleared AK Steel Corp. and two other U.S. steelmakers in a patent infringement suit brought by rival ArcelorMittal SA, finding that its patent for aluminum-coated boron steel used in automobile frames was obvious and, therefore, invalid.
January 14, 2011
A jury began deliberations Friday in steel giant ArcelorMittal's suit accusing three U.S. rivals of infringing its patent for making aluminum-coated steel sheets used in automobile frames.
January 11, 2011
Steel giant ArcelorMittal questioned trial witnesses Tuesday as it tried to prove three U.S. competitors infringed on its patent for aluminum-coated steel sheets to provide a domestic supply of the product to major U.S. auto manufacturers.