ownership interests
(4) Ownership interests. The term ownership interests means stock in a corporation and partnership interests in a partnership. (5) Significant portion. With respect to the assets of an eligible QBU, the term significant portion means a significant portion of the operating assets, determined based on all the facts and circumstances, provided that more than 30 percent of the operating assets will constitute a significant portion in all cases and less than 10 percent of the operating assets will not constitute a significant portion in all cases.