The Court found that USX was a “prevailing party” on a claim before the district court, even though USX prevailed on the issue of invalidity in a different forum (a PTO reexamination). (U.S. Patents 4,421,574 and 4,483,723). Thus, USX may have a right to attorney fees and costs under 35 U.S.C. 285 and Rule 54(d) of the Federal Rules of Civil Procedure. The major indication of the status of prevailing party cited by the Court is that the case would have res judicata effect as to any claims brought against USX in the future with respect to the patent claims that were at issue in the district court case.
Reversed and remanded to determine whether the case is “exceptional” or if the court should exercise its discretion to allow or deny costs to the prevailing party.