“ A business transaction of great magnitude and importance, which the Federal Power Commission has found to be in the public interest, is, at least for the time being, set for naught, without the slightest inquiry into whether the antitrust charges leveled against it are weighty or not. ”

“ Had the Commission stayed its hand and had the courts found the stock acquisition unlawful, the entire transaction would have been set aside in limine. Had the courts found the stock acquisition lawful, presumably no problems under § 7 of the Clayton Act would have remained. When the Commission proceeds in the face of a pending but undecided antitrust suit and approves a merger that has been preceded, as this one was, by a stock acquisition, it in substance treats the entire relation of the companies-from the acquisition of stock to the merger-as an integrated transaction. ”

“ On August 7, 1957, El Paso filed with the Federal Power Commission its application for authorization to merge Pacific's assets with its own. Despite this announced intention further to intermingle the affairs of the two corporations, the Government did not seek temporary relief from the District Court in Utah. El Paso, on the other hand, contended that 'primary jurisdiction' with regard to the merger resided with the Commission and sought to have the antitrust action stayed. ”

“ On the Court's premise that the agency's approval did not immunize the transaction from antitrust liability, the Commission's action in granting the certificate of public convenience and necessity did not more than permit the merger to be consummated subject to all possible antitrust infirmities. ”

“ In reaching our determination, we do not have authority to determine whether a given transaction is in violation of the Clayton Act, but we are required to consider the bearing of the policy of the antitrust laws on the public convenience and necessity. ”

“ Under the Interstate Commerce Act, mergers of carriers that are approved have an antitrust immunity, as § 5 (11) of that Act, 49 U.S.C.A. § 5 (11) , specifically provides that the carriers involved 'shall be and they are hereby relieved from the operation of the antitrust laws * * *.' See McLean Trucking Co. v. United States, 321 U.S. 67, 64 S.Ct. 370, 88 L.Ed. 544.
There is no comparable provision under the Natural Gas Act. ”

“ The Commission's standard, set forth in § 7 of the Natural Gas Act, is that the acquisition, merger, etc., will serve the 'public convenience and necessity.' If existing natural gas companies violate the antitrust laws, the Commission is advised by § 20 (a) to 'transmit such evidence' to the Attorney General 'who, in his discretion, may institute the necessary criminal proceedings.' Other administrative agencies are authorized to enforce § 7 of the Clayton Act when it comes to certain classes of companies or persons ”

“ The decision, on the one hand, in effect transfers to the Antitrust Division of the Department of Justice regulatory functions entrusted to administrative agencies, and on the other hand deprives the courts in government antitrust litigation of the authority given them by statute to determine whether or not interlocutory relief is necessary or appropriate. ”