Example.
Example. P, S, and T file a consolidated return for the calendar year 1969, reflecting a consolidated net operating loss attributable in part to each member. P owns 80 percent of S's stock and S owns 80 percent of T's stock. On January 1, 1970, A purchases 50 percent of P's stock. During 1970 T's business is discontinued. Since there has been a 50 percentage point increase in ownership of P, the common parent of the group, and since T has not continued to carry on the same trade or business after such increase, the portion of the 1969 consolidated net operating loss attributable to T shall not be included in any net operating loss deduction for 1970 or for any subsequent taxable years, whether consolidated or separate.
26 C.F.R. §1.1502-21A