(a) Privilege to file consolidated return. —
(1) An affiliated group of corporations as defined for purposes of filing a consolidated federal income tax return shall, subject to the provisions of this section and in accordance with any regulations prescribed by the Tax Commissioner, have the privilege of filing a consolidated return with respect to the tax imposed by this article for the taxable year in lieu of filing separate returns. The making of a consolidated return shall be upon the condition that all corporations which at any time during the taxable year have been members of the affiliated group are included in the return and consent to the filing of the return. The filing of a consolidated return is considered consent. When a corporation is a member of an affiliated group for a fractional part of the year, the consolidated return shall include the income of the corporation for that part of the year during which it is a member of the affiliated group.