Berkshire Subsidiary Loses Challenge to Insulation Monopoly Suit

Berkshire Hathaway Inc. subsidiary Johns Manville Corp. moved a step closer to a trial of claims that it monopolizes the market for calcium silicon piping insulation, when a federal magistrate in Denver rebuffed its attempt to scotch the antitrust market proposed by a rival.

Magistrate Judge Michael E. Hagerty denied Johns Manville’s partial summary judgment motion, rejecting its argument that a product market consisting of “direct purchasers” of “calsil"—mainly distributors, along with some contractors—was too narrowly drawn. The market definition “passes muster” for now, the judge said.

“Regular market forces such as price do not necessarily affect end user ...