“(a)In General.—The aggregate reduction in the rate of duty applicable to items described in this subsection in effect on any day pursuant to a trade agreement entered into under section 101 of the Trade Act of 1974 [19 U.S.C. 2111] before January 3, 1980, may exceed the limitation in section 109(a) of such Act (19 U.S.C. 2119):“(1) Items amended under section 223(d) of this Act [items 402.00 to 413.51 of the Tariff Schedules] to the extent that they apply to articles which the President determines were not imported into the United States before January 1, 1978, and were not produced in the United States before May 1, 1978.
“(2)(A) Items to the extent that they apply to articles which the President determines are not import sensitive and are the product of a least developed developing country as defined in the United Nations General Assembly list of “Least Developed Countries” and which are beneficiary developing countries under section 502 of the Trade Act of 1974 [19 U.S.C. 2462]. “(B) The President may at any time suspend the treatment accorded under subparagraph (A) in which case the aggregate reduction in effect for such products shall be the reduction in effect for countries other than least developed developing countries.
“(3) Item 628.57. Notwithstanding the first sentence of this subsection, the limitation in section 109(a) of the Trade Act of 1974 may be exceeded only to the extent necessary to permit an aggregate reduction of 4.8 percent ad valorem in the rate of duty in effect under such item during the first 1-year period after the effective date of the first reduction in the rate of duty proclaimed for such item.
“(4) Items 132.50, 170.10, 170.15, 170.20, 177.62, 186.15, and 429.47.
“(5) Items 306.31, 306.32, 306.33, and 306.34. Notwithstanding subsection (a), the limitation in section 109(a) of the Trade Act of 1974 may be exceeded only to the extent necessary to permit the total reduction proclaimed under section 101 of the Trade Act of 1974 relating to such item to take effect within 2 years after the effective date of the first reduction in the rate of duty proclaimed for such item.
“(6) Items for which the President determines the effective date of the first reduction will be after June 30, 1980, and before January 1, 1981, to the extent necessary to permit the second reduction to take effect on January 1, 1981.
