((a)) Notwithstanding any final judgment rendered in any action brought by the United States under which a joint operating arrangement has been held to be unlawful under any antitrust law, any party to such final judgment may reinstitute said joint newspaper operating arrangement to the extent permissible under .

((b)) The provisions of shall apply to the determination of any civil or criminal action pending in any district court of the United State  on , in which it is alleged that any such joint operating agreement is unlawful under any antitrust law.