For purposes of this part, the term “dividend” shall, except as otherwise provided in this section, include only dividends described in section 316 (relating to definition of dividends for purposes of corporate distributions).

The amount of any distribution shall not be considered as a dividend for purposes of computing the dividends paid deduction, unless such distribution is pro rata, with no preference to any share of stock as compared with other shares of the same class, and with no preference to one class of stock as compared with another class except to the extent that the former is entitled (without reference to waivers of their rights by shareholders) to such preference. In the case of a distribution by a regulated investment company to a shareholder who made an initial investment of at least $10,000,000 in such company, such distribution shall not be treated as not being pro rata or as being preferential solely by reason of an increase in the distribution by reason of reductions in administrative expenses of the com­pany.

In the case where a corporation which is a member of an affiliated group of corporations filing or required to file a consolidated return for a taxable year is required to file a separate personal holding company schedule for such taxable year, a distribution by such corporation to another member of the affiliated group shall be considered as a dividend for purposes of computing the dividends paid deduction if such distribution would constitute a dividend under the other provisions of this section to a recipient which is not a member of an affiliated group.

In the case of a real estate investment trust, in determining the amount of dividends under section 316 for purposes of computing the dividends paid deduction, the earnings and profits of such trust for any taxable year beginning after December 31, 1980, shall be increased by the total amount of gain (if any) on the sale or exchange of real property by such trust during such taxable year.