opinion: PER CURIAM:
  We affirm the order of the district court denying appellants’ motion for summary judgment. We affirm on the grounds stated in the district court’s opinion, except that we do not pass upon the soundness of the district court’s dictum that a government antitrust proceeding filed more than one year subsequent to the termination of a prior government antitrust proceeding could not toll the running of the statute of limitations on private treble damage actions. Nor do we pass upon the contention, made for the first time in a reply brief in this court, that a partial summary judgment should have been granted because American Pipe and Construction Company was not named as a defendant in two of the five civil actions commenced by the government. We see no reason to depart from the general rule that a district court judgment should not be reversed on grounds not raised below. Our affirmance is without prejudice, however, to the filing in the district court by appellants of a motion for partial summary judgment raising this new issue.