A confidential settlement agreement between a large-scale window manufacturer and a flat glass producer is not discoverable by the remaining defendants in the multidistrict litigation case alleging price-fixing among makers of flat glass, a federal judge in Pittsburgh has ruled.

In 2008, the Judicial Panel on Multidistrict Litigation consolidated nine cases in U.S. District Senior Judge Donetta Ambrose’s courtroom in the Western District of Pennsylvania and several more followed. Last year, two parties settled — Oregon-based Jeld-Wen, a plaintiff, and Pittsburgh-based PPG Industries, a defendant. The remaining defendants in the case asked the court to compel discovery of the agreement’s terms, but Ambrose sided with Jeld-Wen, which opposed the motion.