In a publicly-traded company's bylaws, a provision mandating that the consent of more than a simple majority of shareholders is needed for certain actions. These actions, and the specific percentage needed for consent, are outlined in the bylaws and are often used as an anti-takeover measure. For example, a company may require that two-thirds of shareholders must approve of a merger or acquisition. Supermajority provisions exist primarily to ensure the company's independent survival, but they may limit the board of directors' authority in even a friendly takeover. See also: Board-out clause.
A part of a corporation's by-laws that requires an unusually high percentage of stockholder votes in order to bring about certain changes. For example, a firm may require that 80% of shares approve a resolution to call a meeting of stockholders for any purpose other than the annual meeting. This provision makes a corporate takeover more difficult. See also board-out clause.