The Secretary of the Interior shall, not later than 30 days after December 22, 1975, prescribe and make effective a rule which prohibits the bidding for any right to develop crude oil, natural gas, and natural gas liquids on any lands located on the Outer Continental Shelf by any person if more than one major oil company, more than one affiliate of a major oil company, or a major oil company and any affiliate of a major oil company, has or have a significant ownership interest in such person. Such rule shall define affiliate relationships and significant ownership interests.
This section shall not be construed to prohibit the unitization of producing fields to increase production or maximize ultimate recovery of oil or natural gas, or both.