“ The District Court erred in holding that it is the 'unvariable rule' of the Commission to grant existing carriers an opportunity to remedy deficiencies in service, and in holding that carriers have a property right to such opportunity before a new certificate may be issued upon a lawful finding of public convenience and necessity pursuant to the statute. The Commission's power is not so circumscribed. No such limitation has been established by the Commission's own decisions or by judicial determinations. ”

“ Parker, 326 U.S. 60, 70, 65 S.Ct. 1490, 1495, 89 L.Ed. 2051 (1945) ; see Schaffer Transportation Co. v. United States, 355 U.S. 83, 90-91, 78 S.Ct. 173, 177, 178, 2 L.Ed.2d 117 (1957) . Accordingly, we reverse and remand for further proceedings consistent with this opinion. ”