A Delaware federal judge on Sept. 29 denied a last-chance effort by headset-maker Plantronics Inc. to avoid trial next week in a 4-year-old antitrust case that has already cost the company $3 million in sanctions for deleting emails relevant to the case.

Initially filed under seal, the ruling from U.S. District Chief Judge Leonard P. Stark of the District of Delaware denied Plantronics’ motion for summary judgment on rival GN Netcom Inc.’s claims that it had used its agreements with distributors, or PODs, to control prices and prevent competitors from selling headsets to call centers.