delivered the opinion of the Court.
This case presents important questions of procedure arising under Title III of the Communications Act of 1934.1
The respondent is licensed to operate station KOA at Denver, Colorado, on a frequency of 850 kilocycles. Station WHDH, of Boston, Massachusetts, had a license to operate, daytime only, on the same frequency. October 25,1938, WHDH applied to the Communications Commission for an increase in power and for operation unlimited in time. The Commission set down the application and designated certain issues for hearing, of which the following are pertinent: To determine whether the interests of any other stations may be adversely affected by reason of interference, particularly KOA and other named stations; to determine whether public interest, convenience or necessity would be served by modifying the rules governing standard broadcast stations to authorize the proposed operation of WHDH.
The Commission’s rules precluded the operation of a second station at night on KOA’s frequency;2 provided that an application not filed in accordance with its regulations would be deemed defective, would not be considered, and would be returned to the applicant;3 and also that if an applicant desired to challenge the validity or wisdom of any rule or regulation he must submit a petition setting forth the desired change and the reasons in support thereof.4
The respondent petitioned to intervene. Its petition was denied. It then moved to dismiss WHDH’s applica*241tion for failure to conform to the rules and regulations. The motion was denied. Meantime the Commission evidently believing that, in view of the possible alteration of the rules concerning standard broadcast stations, questions of policy might be involved and that, consequently, under § 409 (a), the hearing would have to be conducted by a member of the Commission,5 designated Commissioner Case to conduct the hearing.
No hearing was held under the original notice. A new notice was issued which indicated that the Commission did not then contemplate modification of its substantive rules but intended merely to afford the applicant an opportunity to urge that they be construed in the applicant’s favor. Issues specified in the second notice were “to determine whether or not the Commission’s Rules Governing Standard Broadcast Stations, particularly Sections 3.22 and 3.25 (Part III) properly interpreted and applied preclude the granting of the application” and to determine the nature, extent, and effect of any interference which would result from a grant of the application, particularly with station KOA and others named. The inquiry thus limited could be heard before an examiner under § 409 (a) and, accordingly, the Commission withdrew the designation of Commissioner Case and assigned an examiner.
A hearing was held January 29 and 30,1940, but the respondent was not permitted to appear or participate. December 9,1940, the Commission promulgated proposed findings of fact and conclusions. Two commissioners dissented. All agreed that §§ 3.22 and 3.25 of the regulations precluded a grant of WHDH’s application. Three voted to modify those regulations and to grant the *242application. Respondent then filed its second petition to intervene, which was denied. The Commission subsequently, on its own motion, permitted respondent to file briefs and present an oral argument amicus curiae. April 7, 1941, the Commission adopted a final order amending § 3.25 of the rules and granting the WHDH application, two commissioners dissenting.
Respondent filed a petition for rehearing pursuant to § 405 of the Act.6 This was denied. Thereupon respondent gave notice of appeal to the Court of Appeals for the District of Columbia,7 which concluded that the Commission’s action effected a modification of respondent’s license and consequently the statute entitled the respondent to be made a party and to participate in the hearing. The court below therefore reversed the Commission’s order and remanded the case for further proceedings.8
The respondent contends that it was entitled, as a matter of right, to participate in the hearing before the Commission on the question of the granting of WHDH’s application and that its rights in this respect were not satisfied by permitting it to file a brief and present argument. It further insists that the Commission’s proceeding was invalid due to the provisions of § 409 (a) of the statute, the failure to comply with the rules then in force, and the arbitrary and capricious action taken. Finally, the respondent asserts § 405 entitled it to a rehearing and § 402 (b) (2) granted it an appeal.
The petitioner urges that the grant of WHDH’s application did not amount to a substantial modification of KOA’s license or so affect KOA’s rights as to require that KOA be permitted to intervene, and that, in any event, KOA was not denied any substantial right of participation in the proceeding.
*243First. We are of opinion that respondent was entitled to be made a party.
Section 312 (b) of the Act provides:
“Any station license hereafter granted . . . may be modified by the Commission . . ., if in the judgment of the Commission such action will promote the public interest, convenience, and necessity . . . Provided, however, That no such order of modification shall become final until the holder of such outstanding license . . . shall have been notified in writing of the proposed action and the grounds or reasons therefor and shall have been given reasonable opportunity to show cause why such an order of modification should not issue.”
The Commission found that there would be interference with KOA’s broadcast in the eastern part of the United States if WHDH’s application were granted. The Commission’s own reports to Congress show that at night a small proportion of the urban population and a much larger proportion of the rural population of the country enjoy only such broadcasting service as is afforded by clear channel stations. KOA, one of the stations upon which this service depends, has operated continuously at Denver since 1924 and has used a clear channel upon which only one station is permitted to operate during the night. Under the Commission’s regulations (§§ 3.22 and 3.25) KOA had, therefore, little or no channel interference from any station located within the United States. In addition, its signals throughout the United States were free, and entitled to remain free, of channel interference from any station in Canada, Mexico or Cuba, pursuant to the provisions of the North American Regional Broadcasting Agreement.9 The Commission’s order deprives KOA of freedom from interference in its night service over a large area lying east of the Mississippi River. Furthermore, the order opens the way for Canada, Mexico, and Cuba, *244signatories to the broadcasting agreement, to acquire the right to operate stations which may cause channel interference at night on KOA’s frequency within the United States.
The respondent urges that it can be shown that the service of WHDH, while interfering at night with that of KOA, would not be a service equally useful, and that the grant to WHDH adds a new primary service to an area already heavily supplied with such service. In its petitions to intervene, the respondent called attention to the terms of its existing license, asserting that the grant of WHDH’s application would cause interference in areas where KOA’s signal was interference free; that respondent would be aggrieved and its interests adversely affected by a grant of the application and that the operation proposed by WHDH would not be in the interest of public convenience and necessity; that a grant of the application would result in a modification of respondent’s license in violation of § 312 (b) and would result in a modification of the Commission’s regulations without such a hearing as is required by § 303 (f) of the Act. In its petition for rehearing, the respondent elaborated and reiterated the reasons embodied in its motions for dismissal of the petition and in its petitions to intervene.
The Commission says that the section has no application to this case. It asserts that the proceeding was an application by WHDH for modification of its station license and that, under § 309 (a) of the Act, the Commission might have acted on the application without any hearing. ' So much may be conceded, if nothing more were involved. But the grant of WHDH’s application, in the circumstances, necessarily involved the modification of KOA’s outstanding license. This petitioner denies, saying KOA’s license granted no more than the privilege of operating its station in a prescribed manner and that the grant of WHDH’s application in nowise altered the terms *245of KOA’s license. This contention stems from the circumstance that KOA’s license authorizes it to operate a transmitter of 50 kilowatts on the frequency 850 kilocycles at Denver. The petitioner says that the grant of WHDH’s application affects none of these terms. But we think this too narrow a view. When KOA’s license was granted the Commission’s rules §§ 3.21 and 3.25 embodied these provisions:
“A ‘clear channel’ is one on which the dominant station or stations render service over wide areas and which are cleared of objectionable interference within their primary service areas and over all or a substantial portion of their secondary service areas.”
“The frequencies in the following tabulation are designated as clear channels and assigned for use by the classes of stations are given:
“(a) To each of the channels below there will be assigned one class I station and there may be assigned one or more class II stations operating limited time or daytime only: . . . The power of the class I stations on these channels shall not be less than 50 kilowatts.”
850 kilocycles was one of the frequencies appearing on the schedule forming part of the rule.
These rules were incorporated into the terms of KOA’s license which granted it a frequency of 850 kilocycles and a power of 50 kilowatts. To alter the rules so as to deprive KOA of what had been assigned to it, and to grant an application which would create interference on the channel given it, was in fact and in substance to modify KOA’s license. This being so, § 312 (b) requires that it be made a party to the proceeding. We can accord no other meaning to the language of the proviso which requires that the holder of the license which is to be modified must have notice in writing of the proposed action and the grounds therefor and must be given a reasonable *246opportunity to show cause why an order of modification should not issue. Certainly one who is to be notified of a hearing and to have the right to show cause is not to be considered a stranger to the proceeding but is, by the very provisions of the statute, to be made a party. The very notices issued by the Commission show that that body knew there would probably be an interference with KQA’s signals if the pending application of WHDH were granted; and that the Commission also realized there was a serious question whether the application could be granted under its existing rules. It is not necessary to discuss at any length the sufficiency of the petitions to intervene if, as we have held, the Act itself provided that, in such an instance as the present, KOA was entitled to be brought in as a party. A licensee cannot show cause unless it is afforded opportunity to participate in the hearing, to offer evidence, and to exercise the other rights of a party.
Much is said to the effect that KOA was not in fact injured, because the Commission permitted it to file a brief amicus curiae and to present oral argument. It is beside the point to discuss the Commission’s rules as to intervention and the privileges accorded by the Commission to one denied intervention, since we are of opinion, as already stated, that, under the terms of the Act, the respondent was entitled to participate in the proceedings. . . .
Second. While the Commission did not urge before the court below, and did not advance as-a reason for the. grant of certiorari, that respondent was not entitled to appeal to the Court of Appeals, this matter was argued here and, as it raises a question of jurisdiction, we shall consider it.
It would be anomalous if one entitled to be heard before the Commission should be denied the right of appeal from an order made without hearing. We think the Act does not preclude such an appeal. Section 402 (b) (2) .permits an appeal to the Court of Appeals for the District of Cq*247lumbia by “any . . . person aggrieved or whose interests are adversely affected by any decision of the Commission granting or refusing” any application for modification of an existing station license. If, within the intent of the statute, the interests of KOA would be adversely affected, or if KOA would be aggrieved by granting the application of WHDH, then the statute grants KOA a right of appeal.
In Federal Communications Commission v. Sanders Bros. Radio Station, 309 U. S. 470, we dealt with a similar situation. There the question was whether a rival station, which would suffer economic injury by the grant of a license to another station, had standing to appeal under the terms of the Act. We held that it had. We pointed out that while a station license was not a property right, and while the Commission was not bound to give controlling weight to economic injury to an existing station consequent upon the issuance of a license to another station, yet economic injury gave the existing station standing to present questions of public interest and convenience by appeal from the order of the Commission. Here KOA, while not alleging economic injury, does allege that its license ought not to be modified because such action would cause electrical interference which would be detrimental to the public interest.
In view of the fact that § 312 (b) grants KOA the right to become a party to the proceedings, we think it plain that it is a party aggrieved, or a party whose interests will be adversely affected by the grant of WHDH’s application, as indeed'the Commission seems to have thought when it first noticed WHDH’s application for hearing. We, therefore, hold KOA was entitled to appeal from the Commission’s action in excluding it from participation in the proceeding and from the order made by the Commission.
The judgment is
Affirmed.
*248Mr. Justice Black, Mr. Justice Murpht and Mr. Justice Rutledge took no part in the consideration or decision of this case.Act of June 19, 1934, c. 652, 48 Stat. 1064, 1081; 47 U. S. C. § 301 ff.
§§3.22 and 3.25.
§ 1.72.
§ 1.71.
Sec. 409 (a), 47 U. S. C. §409 (a) provides that, in the administration of Tit. Ill, an examiner may not hold hearings with respect to a matter involving a change of policy by the Commission or a new kind of use of frequencies.
47 U. S. C. § 405.
Pursuant to §402 (b) (2); 47 U. S. C. §402 (b) (2).
132 F. 2d 545.
55 Stat., Part 2, 1005.