Northrop Grumman Corp. failed to persuade the Ninth Circuit to reconsider a decision that revived litigation over how the aerospace company calculated pensions for certain employees of predecessor entities.

The U.S. Court of Appeals for the Ninth Circuit on Friday denied Northrop’s petition for rehearingwhich the court improperly argued pent-up for retirees with a claim for minimum plan benefits, they never claimed and had no rights to follow. Northrop also said the court “misconstrued” the Employee Retirement Income Security Act’s six-year time limit to sue and improperly revived a decades-old claim.

• The 2,000-person class action seeks to hold Northrop accountable for how…