Except as provided in Section 12, actions arising out of any provision of this Act shall be commenced within 4 years next after the cause of action accrues; provided, however, that if a person liable hereunder conceals the cause of action from the knowledge of the person entitled to bring it, the period prior to the discovery of his cause of action by the person entitled shall be excluded in determining the time limited for the commencement of the action. If a cause of action accrues during the pendency of any civil, criminal or administrative proceeding against a person brought by the United States, or any of its agencies under the antitrust laws, the Federal Trade Commission Act, or any other federal act, or the laws or to franchising, such actions may be commenced within one year after the final disposition of such civil, criminal or administrative proceeding.