Excerpt: They may not know it yet, but United Airlines employees no longer hold any UAL stock in their 401(k) plans, and their former 55 percent stake in the airline through its ESOP plan is also dwindling. Aon Fiduciary Counselors, the independent fiduciary recently hired to protect 401(k) plan participants, sold all the UAL stock held by the plans before the company filed for bankruptcy on Monday, according to Nell Hennessy, president of the Aon unit.