A countervailing duty proceeding shall be initiated whenever an interested party described in subparagraph (C), (D), (E), (F), or (G) of section
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(9) of this title files a petition with the administering authority, on behalf of an industry, which alleges the elements necessary for the imposition of the duty imposed by section
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(a) of this title, and which is accompanied by information reasonably available to the petitioner supporting those allegations. The petition may be amended at such time, and upon such conditions, as the administering authority and the Commission may permit.