(a) A financial institution shall compute its net earnings:
(1) based on the accounting period used as its fiscal year; and
(2) subject to the modifications required under this section, in the manner that a corporation computes, for purposes of the income tax, the Maryland modified income.
(b) A financial institution shall add to its net earnings computed under subsection (a) of this section the amounts that, even if otherwise allowed to be subtracted under § 10–307(b) and (g)(1) and (4) of this article, equal:
(1) profit realized from the sale or exchange of bonds issued by this State or a political subdivision of this State;
(2) dividends received from foreign corporations and included in federal gross income under § 78 of the Internal Revenue Code;
(3) interest derived from a United States obligation;
(4) State tax–exempt interest received from a mutual fund and allowed to be subtracted under § 10–307(g)(4) of this article; and
(5) interest excluded from federal gross income under § 103 of the Internal Revenue Code and derived from a bond:
(i) issued by a state or a public corporation, special district, political subdivision of a state or their instrumentalities; or
(ii) under § 150 of the Internal Revenue Code, treated as a bond issued by a state or a public corporation, special district, or political subdivision of a state or their instrumentalities.
(c) A financial institution shall subtract from its net earnings computed under subsection (a) of this section interest expense incurred to purchase or carry a bond as defined in subsection (b)(5) of this section.