26 C.F.R. § 1.355-4

Section 355 provides for nonrecognition of gain or loss with respect to a distribution whether or not (a) the distribution is pro rata with respect to all of the shareholders of the distributing corporation, (b) the distribution is pursuant to a plan of reorganization within the meaning of section 368 (a) (1)(D), or (c) the shareholder surrenders stock in the distributing corporation. Under section 355, the stock of a controlled corporation may consist of common stock or preferred stock. (See, however, section 306 and the regulations thereunder.) Section 355 does not apply, however, if the substance of a transaction is merely an exchange between shareholders or security holders of stock or securities in one corporation for stock or securities in another corporation. For example, if two individuals, A and B, each own directly 50 percent of the stock of corporation X and 50 percent of the stock of corporation Y, section 355 would not apply to a transaction in which A and B transfer all of their stock of X and Y to a new corporation Z, for all of the stock of Z, and Z then distributes the stock of X to A and the stock of Y to B.