31 C.F.R. § 850.219
The term parent means, with respect to an entity:
(a) A person who or which directly or indirectly holds more than 50 percent of:
Note 1 to § 850.219: Any entity that meets the conditions of paragraph (a), (b), or (c) of this section with respect to another entity is the parent, even if the parent entity is an intermediate entity and not the ultimate parent.