Limitations of actions.

(a) Actions arising out of any provision of this chapter shall be commenced within a 4-year period of the accrual of the cause of action; 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 a cause of action by the person entitled shall be excluded in determining the time limited for the commencement of the action. (b) 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 [15 U.S.C. §§ 41-58] or any other federal act, or the laws as to franchising, such actions may be commenced within 1 year after the final disposition of such civil, criminal or administrative proceeding.