Director Age and Tenure: How Old Is Too Old?

The issue of director age is pitting some shareholders against corporate boards.

Shareholders recently filed several lawsuits in Delaware alleging that the board of Viacom Inc. breached its fiduciary duty by not accounting for the “chaos that would ensue” at the company when 93-year-old Sumner Redstone becomes incapacitated or passes away.

According to the complaints , Redstone — who owns about 80 percent of Viacom voting stock through a holding company — hasn’t attended a board meeting in person since 2014, yet routinely is renominated to the Viacom board.

Some may argue that the Viacom case is an extreme one, ...