a plan that meets the criteria in subparagraph (A) and (B) of paragraph (1) of this subsection or that is described in subparagraph (E) may, pursuant to procedures prescribed by the Pension Benefit Guaranty Corporation, elect to be a multiemployer plan, if—
(I)#
for each of the 3 plan years immediately preceding the first plan year for which the election under this paragraph is effective with respect to the plan, the plan has met those criteria or is so described,
(II)#
substantially all of the plan’s employer contributions for each of those plan years were made or required to be made by organizations that were exempt from tax under section 501, and
(III)#
the plan was established prior to September 2, 1974 .