(a) Maximum Deposits.—The amount deposited in a capital construction fund for a taxable year may not exceed the sum of—

(1) that portion of the taxable income of the owner or lessee for the taxable year (computed under chapter 1 of the Internal Revenue Code of 1986 (26 U.S.C. ch. 1) but without regard to the carryback of net operating loss or net capital loss or this chapter) that is attributable to the operation of agreement vessels in the foreign or domestic trade of the United States or in the fisheries of the United States;

(2) the amount allowable as a deduction under section 167 of such Code (26 U.S.C. 167) for the taxable year for agreement vessels;

(3) if the transaction is not taken into account for purposes of paragraph (1), the net proceeds (as defined in joint regulations) from the disposition of an agreement vessel or from insurance or indemnity attributable to an agreement vessel; and

(4) the receipts from the investment or reinvestment of amounts held in the fund.

(b) Reductions for Lessees.—For a lessee, the maximum amount that may be deposited for an agreement vessel under subsection (a)(2) for any period shall be reduced by any amount the owner is required or permitted, under the capital construction fund agreement, to deposit for that period for the vessel under subsection (a)(2).