“ All we hold is that the controversy at present is not one appropriate for judicial action.
Section 10 of the Administrative Procedure Act, 60 Stat. 243, 5 U.S.C. § 1009, 5 U.S.C.A. § 1009, excludes from the categories of cases subject to judicial review 'agency action' that is 'by law committed to agency discretion.' We think the initiation of a proceeding for readjustment of the tolls of the Panama Canal is a matter that Congress has left to the discretion of the Panama Canal Co. Petitioner is, as we have seen, an agent or spokesman of the President in these matters. ”

“ Petitioner is not only agent for the President but a creature of Congress. It is on close terms with its committees, reporting to the Congress, airing its problems before them, looking to Congress for guidance and direction. It is at least arguable that Congress to date has sided with petitioner and against the Comptroller General in construing §§ 411 and 412 of the Code. For Congress, fully advised of the Comptroller General's views in his Report for 1954, approved the budgets for the Panama Canal Co. ”

“ It is 'authorized' to prescribe tolls and to change them. Canal Zone Code, Tit. 2, § 411. But the exercise of that authority is far more than the performance of a ministerial act. As we have seen, the present conflict rages over questions that at heart involve problems of statutory construction and cost accounting: whether an operating deficit in the auxiliary or supporting activities is a legitimate cost in maintaining and operating the Canal for purpose of the toll formula. These are matters on which experts may disagree ”