4—Amendment of section 34A—Standing contracts
(1) Section 34A(4a)(b)—after "a determination" insert:
, other than a determination under paragraph (f),
(2) Section 34A(4a)—after paragraph (e) insert:
(f) if the Commission has determined that special circumstances exist—the Commission may make a determination that takes effect as a variation of the existing determination (with effect for the balance of the term of the existing determination (unless another variation is subsequently made)).