opinion: Mr. Justice White
  delivered the opinion of the Court.
  The issue here is whether the Kentucky Court of Appeals properly enjoined implementation of the decision of a joint employer-employee committee purporting to settle certain grievances in accordance with the terms of a collective bargaining contract. The decision of the committee determined the relative seniority rights of the employees of two companies, Dealers Transport Company of Memphis, Tennessee, and E & L Transport Company of Detroit, Michigan. We are of the opinion that the Kentucky court erred and we reverse its judgment.
  Part of the business of each of these companies was the transportation of new automobiles from the assembly plant of the Ford Motor Company in Louisville, Kentucky. In the face of declining business resulting from several factors, the two companies were informed by Ford that there was room for only one of them in the Louisville operation. After considering the matter for some time, the two companies made these arrangements: E & L would sell to Dealers its “secondary” authority out of Louisville, the purchase price to be a nominal sum roughly equal to the cost of effecting the transfer of authority; E & L would also sell to Dealers its authority to serve certain points in Mississippi and Louisiana; and Dealers would sell to E & L its initial authority out of Lorain, Ohio, along with certain equipment and terminal facilities. The purpose of these arrangements was to concentrate the transportation activities of E & L in the more northerly area and those of Dealers in the southern zone. The transfers were subject to the approval of regulatory agencies.
  The employees of both Dealers and E & L were represented by the same union, General Drivers, Warehouse-men and Helpers, Local Union No. 89. Its president, Paul Priddy, as the result of inquiry from E & L by his assistant, understood that the transaction between the companies involved no trades, sales, or exchanges of properties but only a withdrawal by E & L at the direction of the Ford Motor Company. He consequently advised the E & L employees that their situation was precarious. When layoffs at E & L began three E & L employees filed grievances claiming that the seniority lists of Dealers and E & L should be “sandwiched” and the E & L employees be taken on at Dealers with the seniority they had enjoyed at E & L. The grievances were placed before the local joint committee, Priddy or his assistant meanwhile advising Dealers employees that they had “nothing to worry about” since E & L employees had no contract right to transfer under these circumstances.
  The collective bargaining contract involved covered a multi-employer, multi-local union unit negotiated ,on behalf of the employers by Automobile Transporters Labor Division and on behalf of the unions by National Truck-away and Driveaway Conference. Almost identical contracts were executed by each company in the unit and by the appropriate local union. According to Art. 4, § 1 of the contract “seniority rights for employees shall prevail” and “any controversy over the employees’ standing on such lists shall be submitted to the joint grievance procedure. . . .” Section 5 of the same article, of central significance here, was as follows:
  “In the event that the Employer absorbs the business of another private, contract or common carrier, or is a party to a merger of lines, the seniority of the employees absorbed or affected thereby shall be determined by mutual agreement between the Employer and the Unions involved. Any controversy with respect to such matter shall be submitted to the joint grievance procedure.”
  Article 7 called for grievances to be first taken up between the employer and the local union and, if not settled, to be submitted to the local joint committee where the union and the employer were to have equal votes. Failing settlement by majority vote of the members of the local committee, the matter could be taken to the Automobile Transporters Joint Conference Committee upon which the employers and the unions in the overall bargaining unit had an equal number of representatives. Decisions of the Joint Conference Committee were to be “final and conclusive and binding upon the employer and the union, and the employees involved.” However, if the Joint Conference Committee was unable to reach a decision the matter was to be submitted to arbitration as provided in the contract.
  Article 7 also provided that:
  (d) “It is agreed that all matters pertaining to the interpretation of any provision of this Agreement, whether requested by the Employer or the Union, must be submitted to the full Committee of the Automobile Transporters Joint Conference Committee, which Committee, after listening to testimony on both sides, shall make a decision.”
  Other provisions of the contract stated that it was “the intention of the parties to resolve all questions of interpretation by mutual agreement” and that the employer agreed “to be bound by all of the terms and provisions of this Agreement, and also agrees to be bound by the interpretations and enforcement of the Agreement.”
  The grievances of the E & L employees were submitted directly to the local joint committee and endorsed “Deadlocked to Detroit for interpretation” over the signatures of the local union president and the Dealers representative on the committee. Later, however, the local union, having been more fully advised as to the nature of the transaction between the two companies, decided to recommend to the Joint Conference Committee that the seniority lists of the two companies be dovetailed and the E & L employees be employed at Dealers with seniority rights based upon those which they had enjoyed at E & L. The three shop stewards who represented the Dealers employees before the Joint Conference Committee meeting in Detroit were so advised by the union immediately prior to the opening of the hearing. After hearing from the company, the union and the stewards representing Dealers employees, the Joint Conference Committee thereupon determined that “in accordance with Article 4 and particularly sub-sections 4 and 5” of the agreement the employees of E & L and of Dealers should “be sandwiched in on master seniority boards using the presently constituted seniority lists and the dates contained therein . . . .”
  Since E & L was an older company and most of its employees had more seniority than the Dealers employees, the decision entailed the layoff of a large number of Dealers employees to provide openings for the E & L drivers.
  Respondent Moore, on behalf of himself and other Dealers employees, then brought this class action in a Kentucky state court praying for an injunction against the union and the company to prevent the decision of the Joint Conference Committee from being carried out. Damages were asked in an alternative count and certain E & L employees were added as defendants by amendment to the complaint. The complaint alleged that Dealers employees had relied upon the union to represent them, that the president of Local 89, Paul Priddy, assured Dealers employees that they had nothing to worry about and that precedent in the industry provided that when a new business is taken over, its employees do not displace the original employees of the acquiring company; it further alleged that Priddy had deliberately “deadlocked” the local joint committee and that the Dealers employees learned for the first time before the Joint Conference Committee in Detroit, that Priddy favored dovetailing the seniority lists. Priddy’s actions, the complaint went on, “in deceiving these plaintiffs as to his position left them without representation before the Joint Conference Committee.” The decision, according to the complaint, was “contrived, planned and brought about by Paul Priddy” who “has deceived and failed completely to represent said employees” and whose “false and deceitful action” and “connivance . . . with the employees of E & L” threatened the jobs of Dealers employees. The International union is said to have “conspired with and assisted the defendant, Local No. 89, and its president, Paul Priddy, in bringing about this result . . . .” The decision of the Joint Conference Committee was charged to be arbitrary and capricious, contrary to the existing practice in the industry and violative of the collective bargaining contract.
  After hearing, the trial court denied a temporary and permanent injunction. The Court of Appeals of the Commonwealth of Kentucky reversed and granted a permanent injunction, two judges dissenting. 356 S. W. 2d 241. In the view of that court, Art. 4, § 5 could have no application to the circumstances of this case since it came into play only if the absorbing company agreed to hire the employees of the absorbed company. The clause was said to deal with seniority, not with initial employment. Therefore, it was said, the decision of the Joint Conference Committee was not binding because the question of employing E & L drivers was not “arbitrable” at all under this section. The Court of Appeals, however, went on to hold that even if it were otherwise, the decision could not stand since the situation involved antagonistic interests of two sets of employees represented by the same union advocate. The result was inadequate representation of the Dealers employees in a context where Dealers itself was essentially neutral. Against such a backdrop, the erroneous decision of the board became “arbitrary and violative of natural justice.” Kentucky cases were cited and relied upon. We granted both the petition filed by the E & L employees in No. 17 and the petition in No. 18, filed by the local union. 371 U. S. 966, 967.
  I.
  Since issues concerning the jurisdiction of the courts and the governing law are involved, it is well at the outset to elaborate upon the statement of the Kentucky court that this is an action to enforce a collective bargaining contract, an accurate observation as far as we are concerned.
  First, Moore challenges the power of the parties and of the Joint Conference Committee to dovetail seniority lists of the two companies because there was no absorption here within the meaning of § 5 of Art. 4 and because, as the court below held, that section granted no authority to deal with jobs as well as seniority. His position is that neither the parties nor the committee has any power beyond that delegated to them by the precise terms of § 5. Since in his view the Joint Committee exceeded its power in making the decision it did, the settlement is said to be a nullity and his impending discharge a breach of contract.
  Second, Moore claims the decision of the Committee was obtained by dishonest union conduct in breach of its duty of fair representation and that a decision so obtained cannot be relied upon as a valid excuse for his discharge under the contract. The undoubted broad authority of the union as exclusive bargaining agent in the negotiation and administration of a collective bargaining contract is accompanied by a responsibility of equal scope, the responsibility and duty of fair representation. Syres v. Oil Workers Union, 350 U. S. 892, reversing 223 F. 2d 739; Brotherhood of Railroad Trainmen v. Howard, 343 U. S. 768; Tunstall v. Brotherhood of Locomotive Firemen & Enginemen, 323 U. S. 210; Steele v. Louisville & N. R. Co., 323 U. S. 192. “By its selection as bargaining representative, it has become the agent of all the employees, charged with the responsibility of representing their interests fairly and impartially.” Wallace Corp. v. Labor Board, 323 U. S. 248, 255. The exclusive agent’s obligation “to represent all members of an appropriate unit requires [it] to make an honest effort to serve the interests of all of those members, without hostility to any . . .’’and its powers are “subject always to complete good faith and honesty of purpose in the exercise of its discretion.” Ford Motor Co. v. Huffman, 345 U. S. 330, 337-338.
  In the complaint which Moore filed here, the union is said to have deceived the Dealers employees concerning their job and seniority rights, deceitfully connived with the E & L drivers and with the International union to deprive Moore and others of their employment rights and prevented the latter from having a fair hearing before the Joint Committee by espousing the cause of the rival group of drivers after having indicated that the interests of the men at Dealers would be protected by the union. These allegations are sufficient to charge a breach of duty by the union in the process of settling the grievances at issue under the collective bargaining agreement.
  Both the local and international unions are charged with dishonesty, and one-half of the votes on the Joint Committee were cast by representatives of unions affiliated with the international. No fraud is charged against the employer; but except for the improper action of the union, which is said to have dominated and brought about the decision, it is alleged that Dealers would have agreed to retain its own employees. The fair inference from the complaint is that the employer considered the dispute a matter for the union to decide. Moreover, the award had not been implemented at the time of the filing of the complaint, which put Dealers on notice that the union was charged with dishonesty and a breach of duty in procuring the decision of the Joint Committee. In these circumstances, the allegations of the complaint, if proved, would effectively undermine the decision of the Joint Committee as a valid basis for Moore’s discharge.
  For these reasons this action is one arising under § 301 of the Labor Management Relations Act and is a case controlled by federal law, Textile Workers Union v. Lincoln Mills, 353 U. S. 448, even though brought in the state court. Local 174, Teamsters v. Lucas Flour Co., 369 U. S. 95; Smith v. Evening News Assn., 371 U. S. 195. Although there are differing views on whether a violation of the duty of fair representation is an unfair labor practice under the Labor Management Relations Act, it is not necessary for us to resolve that difference here. Even if it is, or arguably may be, an unfair labor practice, the complaint here alleged that Moore’s discharge would violate the contract and was therefore within the cognizance of federal and state courts, Smith v. Evening News Assn., supra, subject, of course, to the applicable federal law.
  We now come to the merits of this case.
  II.
  If we assume with Moore and the courts below that the Joint Conference Committee’s power was circumscribed by § 5 and that its interpretation of the section is open to court review, Moore’s cause is not measurably advanced. For in our opinion the section reasonably meant what the Joint Committee said or assumed it meant. There was an absorption here within the meaning' of the section and that section did deal with jobs as well as with seniority.
  Prior to this transaction both E & L and Dealers were transporting new cars out of Louisville for the Ford Motor Company. Afterwards, only one company enjoyed this business, and clearly this was no unilateral withdrawal by E & L. There was an agreement between the companies, preceded by long negotiation. E & L’s authority to engage in the transportation of new cars out of Louisville was sold to Dealers. The business which E & L had done in that city was henceforth to be done by Dealers. While there was no sale of tangible assets at that location, the Joint Conference Committee reasonably concluded that there was an absorption by Dealers of the E & L business within the meaning of § 5 of the contract.
  It was also permissible to conclude that § 5 dealt with employment as well as seniority. Mergers, sales of assets and absorptions are commonplace events. It is not unusual for collective bargaining agreements to deal with them, especially in the transportation industry where the same unions may represent the employees of both parties to the transaction. Following any of such events, the business of the one company will probably include the former business of the other; and the recurring question is whether it is the employees of the absorbed company or those of the acquiring company who are to have first call upon the available work at the latter concern. Jobs, as well as seniority, are at stake; and it was to solve just such problems that § 5 was designed. Its interpretation should be commensurate with its purposes.
  Seniority has become of overriding importance, and one of its major functions is to determine who gets or who keeps an available job. Here § 5 provided for resolving the seniority of not only those employees who are “absorbed,” but all who were “affected” by the absorption. Certainly the transaction “affected” the E & L employees; and the seniority of these drivers, which the parties or the Joint Conference Committee could determine, was clearly seniority at Dealers, the company which had absorbed the E & L business. The parties very probably, therefore, intended the seniority granted an E & L employee at Dealers to carry the job with it, just as seniority usually would. If it did not and if Dealers unilaterally could determine whether to hire any E & L employee, it might decide to hire none, excluding E & L employees from any of the work which they had formerly done. Or if it did hire E & L employees to fill any additional jobs resulting from the absorption of the E & L business, it might select E & L employees for jobs without regard to length of service at E & L or it might insist on an agreement from the union to grant only such seniority as might suit the company. Section 5 would be effectively emasculated.
  The power of the Joint Conference Committee over seniority gave it power over jobs. It was entitled under § 5 to integrate the seniority lists upon some rational basis, and its decision to integrate lists upon the basis of length of service at either company was neither unique nor arbitrary. On the contrary, it is a familiar and frequently equitable solution to the inevitably conflicting interests, which arise in the wake of a merger or an absorption such as occurred here. The Joint Conference Committee’s decision to dovetail seniority lists was a decision which § 5 empowered the committee to make.
  Neither do we find adequate support in this record for the complaint’s attack upon the integrity of the union and of the procedures which led to the decision. Although the union at first advised the Dealers drivers that they had nothing to worry about but later supported the E & L employees before the Joint Conference Committee, there is no substantial evidence of fraud, deceitful action or dishonest conduct. Priddy’s early assurances to Dealers employees were not well founded, it is true; but Priddy was acting upon information then available to him, information received from the company which led him to think there was no trade or exchange involved, no “absorption” which might bring § 5 into play. Other sections of the contract, he thought, would protect the jobs of Moore and his fellow drivers. Consistent with this view, he also advised E & L employees that the situation appeared unfavorable for them. However, when he learned of the pending acquisition by Dealers of E & L operating authority in Louisville and of the involvement of other locations in the transaction, he considered the matter to be one for the Joint Committee. Ultimately he took the view that an absorption was involved, that § 5 did apply and that dovetailing seniority lists was the most equitable solution for all concerned. We find in this evidence insufficient proof of dishonesty or intentional misleading on the part of the union. And we do not understand the court below to have found otherwise.
  The Kentucky court, however, made much of the antagonistic interests of the E & L and Dealers drivers, both groups being represented by the same union, whose president supported one group and opposed the other at the hearing before the Joint Conference Committee. But we are not ready to find a breach of the collective bargaining agent’s duty of fair representation in taking a good faith position contrary to that of some individuals whom it represents nor in supporting the position of one group of employees against that of another. In Ford Motor Co. v. Huffman, 345 U. S. 330, the Court found no breach of duty by the union in agreeing to an amendment of an existing collective bargaining contract, granting enhanced seniority to a particular group of employees and resulting in layoffs which otherwise would not have occurred. “Inevitably differences arise in the manner and degree to which the terms of any negotiated agreement affect individual employees and classes of employees. The mere existence of such differences does not make them invalid. The complete satisfaction of all who are represented is hardly to be expected. A wide range of reasonableness must be allowed' a statutory bargaining representative in serving the unit it represents, subject always to complete good faith and honesty of purpose in the exercise of its discretion.” Id., at 338. Just as a union must be free to sift out wholly frivolous grievances which would only clog the grievance process, so it must be free to take a position on the not so frivolous disputes. Nor should it be neutralized when the issue is chiefly between two sets of employees. Conflict between employees represented by the same union is a recurring fact. To remove or gag the union in these cases would surely weaken the collective bargaining and grievance processes.
  As far as this record shows, the union took its position honestly, in good faith and without hostility or arbitrary discrimination. After Dealers absorbed the Louisville business of E & L, there were fewer jobs at Dealers than there were Dealers and E & L drivers. One group or the other was going to suffer. If any E & L drivers were to be hired at Dealers either they or the Dealers drivers would not have the seniority which they had previously enjoyed. Inevitably the absorption would hurt someone. By choosing to integrate seniority lists based upon length of service at either company, the union acted upon wholly relevant considerations, not upon capricious or arbitrary factors. The evidence shows no breach by the union of its duty of fair representation.
  There is a remaining contention. Even though the union acted in good faith and was entitled to take the position it did, were the Dealers employees, if the union was going to oppose them, deprived of a fair hearing by having inadequate representation at the hearing? Dealers employees had notice of the hearing; they were obviously aware that they were locked in a struggle for jobs and seniority with the E & L drivers, and three stewards representing them went to the hearing at union expense and were given every opportunity to state their position. Thus the issue is in reality a narrow one. There was no substantial dispute about the facts concerning the nature of the transaction between the two companies. It was for the Joint Conference Committee initially to decide whether there was an “absorption” within the meaning of § 5 and, if so, whether seniority lists were to be integrated and the older employees of E & L given jobs at Dealers. The Dealers employees made no request to continue the hearing until they could secure further representation and have not yet suggested what they could have added to the hearing by way of facts or theory if they had been differently represented. The trial court found it “idle speculation to assume that the result would have been different had the matter been differently presented.” We agree.
  Moore has not, therefore, proved his case. Neither the parties nor the Joint Committee exceeded their power under the contract and there was no fraud or breach of duty by the exclusive bargaining agent. The decision of the committee, reached after proceedings adequate under the agreement, is final and binding upon the parties, just as the contract says it is. Drivers Union v. Riss & Co., 372 U. S. 517.
  The decision below is reversed and the cases are remanded for further proceedings not inconsistent with this opinion.
  It is so ordered.
  Mr. Justice Douglas.
  I agree for the reasons stated by my Brother Goldberg that this litigation was properly brought in the state court but on the merits I believe that no cause of action has been made out for the reasons stated by the Court.
  The International union was also named as a party but service was quashed and the action dismissed as against it.
  The denial of a temporary injunction by the trial court was set aside and temporary injunction ordered by the Court of Appeals. Thereafter the trial court dismissed the complaint, but the Court of Appeals reversed and made the temporary injunction permanent.
  In its brief filed here Dealers does not support the decision of the Joint Committee. It suggests, rather, that the matter be finally settled by arbitration under the terms of the contract.
  Section 301 (a) of the L. M. R. A. is as follows:
  "Suits for violation of contracts between an employer and a labor organization representing employees in an industry affecting commerce as defined in this chapter, or between any such labor organizations, may be brought in any district court of the United States having jurisdiction of the parties, without respect to the amount in controversy or without regard to the citizenship of the parties.” 29 U. S. C. §185 (a).
  Compare, for example, Labor Board v. Local 294, International Bro. of Teamsters, 317 F. 2d 746 (C. A. 2d Cir.), with Miranda Fuel Co., 140 N. L. R. B. 181 (1962); enforcement denied, Labor Board v. Miranda Fuel Co., 326 F. 2d 172 (C. A. 2d Cir.). See also Cox, The Duty of Fair Representation, 2 Yillanova L. Rev. 151, 172-175.
  The union contended in the state courts that the jurisdiction of the state courts had been preempted by the federal statutes. The Kentucky Court of Appeals ruled otherwise and the union appears to have abandoned the view here, since it says, relying upon Ford Motor Co. v. Huffman, 345 U. S. 330, that individual employees “may undoubtedly maintain suits against their representative when the latter hostilely discriminates against them.”
  We note that in Syres v. Oil Workers International Union. 350 U. S. 892, individual employees sued the exclusive agent and the company to enjoin and declare void a collective bargaining agreement alleged to violate the duty of fair representation. Dismissal in the trial court was affirmed in the Court of Appeals. This Court reversed and ordered further proceedings in the trial court in the face of contentions made both in this Court and the lower courts that the employees should have brought their proceedings before the National Labor Relations Board. Cf. Cosmark v. Struthers Wells Corp., 54 L. R. R. M. 2333 (Pa. Oct. 17, 1963).
  The E & L employees, petitioners in No. 17, urge that even if the federal courts may entertain suits such as this, the state courts may not. Since in our view the complaint here charged a breach of contract, we find no merit in this position. It is clear that suits for violation of contracts between an employer and a labor organization may be brought in either state or federal courts. Dowd Box Co. v. Courtney, 368 U. S. 502.
  We need not consider the problem posed if § 5 had been omitted from the contract or if the parties had acted to amend the provision. The fact is that they purported to proceed under the section. They deadlocked at the local level and it was pursuant to § 5 that the matter was taken to the Joint Conference Committee which, under Art. 7, was to make a decision “after listening to testimony on both sides.” The committee expressly recited that its decision was in accordance with § 5 of the contract. Even in the absence of § 5, however, it would be necessary to deal with the alleged breach of the union’s duty of fair representation.
  We also put aside the union’s contention that Art. 7, § (d)— providing that all matters of interpretation of the agreement be submitted to the Joint Conference Committee — makes it inescapably clear that the committee had the power to decide that the transfer of operating authority was an absorption within the scope of § 5. But it is by no means clear that this provision in Art. 7 was intended to apply to interpretations of § 5, for the latter section by its own terms appears to limit the authority of the committee to disputes over seniority in the event of an absorption. Reconciliation of these two provisions, going to the power of the committee under the contract, itself presented an issue ultimately for the court, not the committee, to decide. Our view of the scope and applicability of § 5, infra, renders an accommodation of these two sections unnecessary.
  See cases cited in footnote 10, infra.
  See for example, Kent v. Civil Aeronautics Board, 204 F. 2d 263 (C. A. 2d Cir. 1953); Keller v. Teamsters Local 249, 43 CCH Labor Cases ¶ 17,119 (D. C. W. D. Pa. 1961); Pratt v. Wilson Trucking Co., 214 Ga. 385, 104 S. E. 2d 915 (1958); Walker v. Pennsylvania-Reading Seashore Lines, 142 N. J. Eq. 588, 61 A. 2d 453 (1948); In re Western Union Telegraph Co. and American Communications Association (Decisions of War Labor Board 1944) 14 L. R. R. M. 1623. Cf. Colbert v. Brotherhood of Railroad Trainmen, 206 F. 2d 9 (C. A. 9th Cir. 1953); Labor Board v. Wheland Co., 271 F. 2d 122 (C. A. 6th Cir. 1959); Hardcastle v. Western Greyhound Lines, 303 F. 2d 182 (C. A. 9th Cir. 1962); Fagan v. Pennsylvania R. Co., 173 F. Supp. 465 (D. C. M. D. Pa. 1959). "Integration of seniority lists should ordinarily be accomplished on the basis of each employee’s length of service with his original employer Kahn, Seniority Problems in Business Mergers, 8 Industrial and Labor Relations Review 361, 378.
  The Dealers employees rely upon a rider to the Dealers contract protecting the seniority of the employees at a terminal when another terminal of that company is closed down. The court below did not believe the rider dispositive, and we agree.