On the basis of the petition, investigation and consultations, and after receiving the advice of the Section 301 Committee, the Trade Representative shall determine whether U.S. rights under any trade agreement are being denied, or whether any other act, policy, or practice actionable under section 301 exists and, if so, what action (if any) should be taken under section 301. These determinations shall be made:
(a) In the case of an investigation involving a trade agreement (other than the agreement on subsidies and countervailing measures described in section 2(c)(5) of the Trade Agreements Act of 1979), within 30 days after the dispute settlement procedure concludes, or 18 months after the initiation of the investigation, whichever is earlier.
(b) In all other cases, within 12 months after initiating an investigation.