Berkshire Subsidiary Must Face Insulation Monopolization Suit

Berkshire Hathaway Inc. subsidiary Johns Manville Corp. can’t dodge claims that it used exclusive dealing, disparagement of rivals, and unlawful product bundling to monopolize the market for calcium silicon piping insulation, a Denver federal magistrate ruled.

The lawsuit accused Johns Manville of bullying wholesale customers into buying its “calsil” insulation by threatening to withhold, delay, or jack up the price of other industry-leading products it sells. The company, which controls 98% of the calsil insulation market, also threatened to boycott customers that bought from other suppliers, the suit said.

It was filed in the U.S. District Court for the District ...