(1) In case of either a merger or a consolidation of corporations, the absorbed corporations must file final returns covering the period between the close of the preceding reporting period and the date of merger or consolidation.   For taxable years beginning after December 31, 1990, the final return filed on a separate company basis for the period prior to the consolidation is due on the fifteenth day of the fifth month following the close of the first taxable period for which a return is filed on a consolidated basis.   A merger will have no effect on the reporting period of the continuing corporation, and it will file its next return on the basis of its regularly established period.   However, in the case of a consolidation of corporations, the consolidated company is treated as a new corporate entity and files its first return for the period commencing with the date of the consolidation.

(2) Any corporation which acquires another corporation, by any available method, shall be required to report that income and shall be liable for the corporate tax due on their combined entire net income for the year ensuing.