Upon receipt of a request from a Federal agency for his approval under subsection (a) of this section, the Secretary of the Treasury shall act promptly either to grant his approval or to advise the agency of the reasons for withholding his approval. In no case shall the Secretary of the Treasury withhold such approval for a period longer than sixty days unless, prior to the end of such period, he submits to the Congress a detailed explanation of his reasons for so doing. In no case shall the Secretary withhold such approval for a period longer than one hundred and twenty days. To the maximum extent practicable, withholdings of approval shall be made in a manner which is not disproportionately detrimental to the functioning of any particular type of Federal program. Expedited treatment shall be accorded in any case in which the Federal agency advises the Secretary of the Treasury that unusual circumstances require such treatment.
Federal agencies subject to this section shall submit financing plans to the Secretary of the Treasury at such times and in such forms as he shall prescribe.