On Wednesday, a federal judge will begin weighing whether Boeing Co. mishandled its 401(k) plan by offering imprudent investment options and allowing excessive fees to get passed on to employees.

The class-action suit, filed on behalf of 190,000 Boeing employees and retirees, has been in court for almost a decade. On the plaintiffs’ side is a St. Louis lawyer known for waging yearslong battles over retirement plans. Boeing is his biggest target to date.

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