opinion: NATIONAL LABOR RELATIONS BOARD v. AMAX COAL CO., A DIVISION OF AMAX, INC., et al.
  No. 80-692.
  Argued April 28, 1981
  Decided June 29, 1981
  Stewart, J., delivered the opinion of the Court, in which Burger, C. J., and BrenNAN, White, Marshall, Blackmun, Powell, and Rehnquist, JJ., joined. Stevens, J., filed a dissenting opinion, post, p. 339.
  Harrison Combs argued the cause for petitioners in No. 80-289. With him on the briefs were J. Craig Kuhn, Melvin P. Stein, and James C. Kuhn III.
  Harlon L. Dalton argued the cause for the National Labor Relations Board in both cases. On the briefs were Solicitor General McCree, Andrew J. Levander, Robert E. Allen, Norton J. Come, Linda Sher, and Richard B. Bader.
  Daniel F. Gruender argued the cause for respondent Amax Coal Co., a Division of Amax, Inc., in both cases. With him on the brief was Raymond K. Denworth, Jr.
  Together with No. 80-289, United Mine Workers of America, Local No. 1854, et al. v. National Labor Relations Board et al., also on certiorari to the same court.
  Briefs of amici curiae urging reversal were filed by Robert J. Ferdon, Julia Penny Clark, J. Albert Woll, Laurence Gold, and David R. Boyd, for the American Federation of Labor and Congress of Industrial Organizations et al.; by Charles P. O’Connor and Harry A. Rissetto for the Bituminous Coal Operators’ Association, Inc.; and by E. Ccdvin Golumbic for the Board of Trustees of the United Mine Workers of America Health and Retirement Funds.
  Justice Stewart
  delivered the opinion of the Court.
  This litigation concerns the relationship between two important provisions of the Labor Management Relations Act, 1947 (LMRA). Section 8 (b)(1)(B) of the National Labor Relations Act, as amended by § 101 of the LMRA, 61 Stat. 141, makes it an unfair labor practice for a union “to restrain or coerce ... an employer in the selection of his representatives for the purposes of collective bargaining or the adjustment of grievances . ...” Section 302 (c) (5) of the LMRA, 61 Stat. 157, permits employers and unions to create employer-financed trust funds for the benefit of employees, so long as employees and employers are equally represented by the trustees of the funds. The question at issue is whether the employer-selected trustees of a trust fund created under § 302 (c)(5) are “representatives” of the employer “for the purposes of collective bargaining or the adjustment of grievances” within the meaning of § 8 (b)(1)(B).
  I
  The Amax Coal Co. owns several deep-shaft bituminous coal mines, most of them in the Midwestern United States. The United Mine Workers of America (the union) represents Amax’s employees, and, with respect to the midwestern mines, Amax is a member of the Bituminous Coal Operators Association (BCOA), a national multiemployer group that bargains with the union. Through its collective-bargaining contract with the union, Amax, along with the other members of the BCOA, agreed to contribute to the union’s national pension and welfare trust funds. These funds, established under § 302 (c) (5) of the Act, provide comprehensive health and retirement benefits to coal miners and their families. In accord with § 302 (c) (5) (B), the trust funds are administered by three trustees, one selected by the union, one by the members of BOCA, and one by the other two.
  In 1972, Amax opened the Belle Ayr Mine in Wyoming, the company’s first sub-bituminous surface mine. Although Amax did not join the BCOA with respect to that mine, Amax and the union negotiated a collective-bargaining contract for Belle Ayr which resembled the BCOA national contract, and under which Amax contributed specified amounts of money to the national trust funds to benefit the employees at Belle Ayr. In January 1975, when the collectively bargained contract covering the Belle Ayr Mine ended, the union struck Belle Ayr and other western mines, attempting to compel the mine owners to establish a multiemployer bargaining unit and to agree to a new collective contract proposed by the union, under which the members of the new employer unit would contribute to the national trust funds. Amax resisted, and the union, threatened with a complaint from the National Labor Relations Board Regional Counsel for illegally attempting to coerce the employer into a multiemployer bargaining unit, soon began separate negotiations with Amax. Those negotiations came to an impasse, and the union continued its strike at the Belle Ayr Mine. Amax then filed with the Board unfair labor practice charges against the union.
  The matter of pension and welfare benefits had been a major barrier to agreement between Amax and the union, and formed an important part of Amax’s charges before the Board. Amax had proposed its own benefit and pension trust plan, outside the purview of § 302 (c)(5), but the union, claiming that such a plan would not be sufficiently portable to or reciprocal with the national trust funds, had rejected this proposal. Rather, the union had insisted that Amax, even as a separately bargaining employer, continue to contribute to the national trust funds for the Belle Ayr employees. Amax, of course, as a member of BCOA, had participated in selecting the management-appointed trustee of the national trust funds, but it now wanted to appoint its own trustee for any trust fund covering the employees of the Belle Ayr Mine. Amax took the view that any management-appointed trustee of a § 302 (c)(5) trust fund was a collective-bargaining “representative” of the employer within the meaning of § 8 (b)(1)(B); therefore, since the management trustee of the national trust fund had already been selected by BCOA, Amax contended that the union’s insistence that it participate in the national trust funds with regard to Belle Ayr employees constituted illegal coercion under §8 (b)(1)(B) of the Act. Amax also charged the union with refusing to bargain in good faith in violation of § 8 (b) (3) of the Act.
  The National Labor Relations Board unanimously concluded that the union had acted legally in bargaining to impasse and striking to obtain Amax’s participation in the national trust funds for the Belle Ayr employees. The Board noted that the purpose of § 8 (b)(1) (B) was to ensure that an employer can bargain through a freely chosen representative completely faithful to his interests under the principles of agency law, while the trustee of a joint trust fund, though he may appropriately consider the recommendations of the party who appoints him, is a fiduciary owing undivided loyalty to the interest of the beneficiaries in administering the trust. Accordingly, the Board concluded that the union had not violated § 8 (b)(1)(B).
  On cross-petitions by the parties, the Court of Appeals for the Third Circuit, relying on its earlier decision in Associated Contractors of Essex County, Inc. v. Laborers International Union, 559 F. 2d 222, 227-228, held that management-appointed trustees of a § 302 (c) (5) trust fund act as both fiduciaries of the employee-beneficiaries and as agents of the appointing employers, and, insofar as is consistent with their fiduciary obligations, are expected to administer the trusts in such a way as to advance the employer’s interests. 614 F. 2d 872, 881-882. The court therefore concluded that the union had acted in violation of §8 (b)(1)(B) in exerting its economic power to induce Amax to participate in the national trust funds with respect to employees of the Belle Ayr Mine, and reversed the Board’s ruling to the contrary. We granted certiorari to consider the important question of federal labor law these cases present. 449 U. S. 1110.
  II
  Although § 302 (a) of the Act generally prohibits an employer from making payments to any representative of his employees, § 302 (c)(5) allows an employer to contribute to an employee benefit trust fund that satisfies certain statutory requirements. To ensure that the funds in such a trust are not used as a union “war chest,” Arroyo v. United States, 359 U. S. 419, 426, the Act provides that the funds may be used only for specified benefits for employees and their dependents, and that the basis for these payments be laid out in a detailed written agreement between the union and the employer. The fund must be subject to an annual audit, and the results of the audit must be made available to all interested persons. Furthermore, pension or annuity funds must be kept in a trust separate from other union welfare funds. Finally, § 302 (c) (5) (B) requires that “employees and employers [be] equally represented in the administration of such fund, together with such neutral persons as the representatives of the employers and the representatives of the employees may agree upon . . .
  Congress directed that union welfare funds be established as written formal trusts, and that the assets of the funds be “held in trust,” and be administered “for the sole and exclusive benefit of the employees . . . and their families and dependents . . . .” 29 U. S. C. § 186 (c)(5). Where Congress uses terms that have accumulated settled meaning under either equity or the common law, a court must infer, unless the statute otherwise dictates, that Congress means to incorporate the established meaning of these terms. See Perrin v. United States, 444 U. S. 37, 42-43. Under principles of equity, a trustee bears an unwavering duty of complete loyalty to the beneficiary of the trust, to the exclusion of the interests of all other parties. Restatement (Second) of Trusts § 170 (1) (1957); 2 A. Scott, Law of Trusts § 170 (1967). To deter the trustee from all temptation and to prevent any possible injury to the beneficiary, the rule against a trustee dividing his loyalties must be enforced with "uncompromising rigidity.” Meinhard v. Salmon, 249 N. Y. 458, 464, 164 N. E. 545, 546 (Cardozo, C. J.). A fiduciary cannot contend “that, although he had conflicting interests, he served his masters equally well or that his primary loyalty was not weakened by the pull of his secondary one.” Woods v. City National Bank & Trust Co., 312 U. S. 262, 269.
  Given this established rule against dual loyalties and Congress’ use of terms long established in the courts of chancery, we must infer that Congress intended to impose on trustees traditional fiduciary duties unless Congress has unequivocally expressed an intent to the contrary. See Owen v. City of Independence, 445 U. S. 622, 637. However, although § 302 (c)(5)(B) requires an equal balance between trustees appointed by the union and those appointed by the employer, nothing in the language of § 302 (c) (5) reveals any congressional intent that a trustee should or may administer a trust fund in the interest of the party that appointed him, or that an employer may direct or supervise the decisions of a trustee he has appointed. And the legislative history of the LMRA confirms that § 302 (c) (5) was designed to reinforce, not to alter, the long-established duties of a trustee.
  As explained by Senator Ball, one of the two sponsors of the provision, the “sole purpose” of § 302 (c) (5) is to ensure that employee benefit trust funds “are legitimate trust funds, used actually for the specified benefits to the employees of the employers who contribute to them . . . .” 93 Cong. Rec. 4678 (1947). Senator Ball stated that “all we seek to do by [§ 302 (c)(5)] is to make sure that the employees whose labor builds this fund and are really entitled to benefits under it shall receive the benefits; that it is a trust fund, and that, if necessary, they can go into court and obtain the benefits to which they are entitled.” Id., at 4753; see H. R. Conf. Rep. No. 510, 80th Cong., 1st Sess., 66-67 (1947), 1 NLRB, Legislative History of the Labor-Management Relations Act, 1947, p. 570 (1948) (Leg. Hist. LMRA). The debates on § 302 (c) (5) further reveal Congress’ intent to cast employee benefit plans in traditional trust form precisely because fiduciary standards long established in equity would best protect employee beneficiaries. For example, one opponent of the bill suggested that § 305 (c) (5) was unnecessary because even without that provision, the “officials who administer [the fund] thereby become trustees, subject to all of the common law and State safeguards against misuse of funds bv trustees.” 93 Cong. Rec. 4751 (1947) (Sen. Morse). Senator Taft, the primary author of the entire Act, answered that many existing funds were not created expressly as trusts, and that § 302 (c) (5)’s requirement that each fund be an express and enforceable trust would ensure that the future operations of all such funds would be subject to supervision by a court of chancery. 93 Cong. Rec. 4753 (1947). See also id., at 4678 (Sen. Ball) ; id., at 3564-3565 (Rep. Case, author of House bill on which § 302 (c)(5) was patterned). In sum, the duty of the management-appointed trustee of an employee benefit fund under § 302 (c)(5) is directly antithetical to that of an agent of the appointing party.
  Whatever may have remained implicit in Congress' view of the employee benefit fund trustee under the Act became explicit when Congress passed the Employee Retirement Income Security Act of 1974 (ERISA), 88 Stat. 829. ERISA essentially codified the strict fiduciary standards that a § 302 (c)(5) trustee must meet. See 29 U. S. C. §§ 1002 (1) and (2); H. R. Conf. Rep. No. 93-1280, pp. 296, 307 (1974). Section 404(a)(1) of ERISA requires a trustee to “discharge his duties . . . solely in the interest of the participants and beneficiaries . . . 29 U. S. C. § 1104 (a)(1). Section 406 (b) (2) declares that a trustee may not “act in any transaction involving the plan on behalf of a party (or represent a party) whose interests are adverse to the interests of the plan or the interests of its participants or beneficiaries.” 29 IT. S. C. §1106 (b)(2). Section 405 (a) imposes on each trustee an affirmative duty to prevent every other trustee of the same fund from breaching fiduciary duties, including the duty to act solely on behalf of the beneficiaries. 29 U. S. C. § 1105 (a).
  Moreover, the fiduciary requirements of ERISA specifically insulate the trust from the employer’s interest. Except in circumstances involving excess contributions or termination of the trust, “the assets of a plan shall never inure to the. benefit of any employer and shall be held for the exclusive purposes of providing benefits to participants in the plan and their beneficiaries and defraying reasonable expenses of administering the plan.” § 403 (c)(1), 29 IT. S. C. § 1103 (c) (1). Finally, §406 (a)(1)(E) prohibits any transaction between the trust and a “party in interest,” including an employer, and § 407 carefully limits the amount and types of employer-owned property and securities that the trustees may obtain for the trust. 29 IT. S. C. §§ 1106 (a)(1)(E), 1107. In sum, ERISA vests the “exclusive authority and discretion to manage and control the assets of the plan” in the trustees alone, and not the employer or the union. 29 IT. S. C. § 1103 (a).
  The legislative history of ERISA confirms that Congress intended in particular to prevent trustees “from engaging in actions where there would be a conflict of interest with the fund, such as representing any party dealing with the fund.” S. Rep. No. 93-383, pp. 31, 32 (1973). In short, the fiduciary provisions of ERISA were designed to prevent a trustee “from being put into a position where he has dual loyalties, and, therefore, he cannot act exclusively for the benefit of a plan’s participants and beneficiaries.” H. R. Conf. Rep. No. 93-1280, supra, at 309.
  Ill
  The language and legislative history of § 302 (c)(5) and ERISA therefore demonstrate that an employee benefit fund trustee is a fiduciary whose duty to the trust beneficiaries must overcome any loyalty to the interest of the party that appointed him. Thus, the statutes defining the duties of a management-appointed trustee make it virtually self-evident that welfare fund trustees are not “representatives for the purposes of collective bargaining or the adjustment of grievances” within the meaning of § 8 (b)(1)(B). But close examination of the latter provision makes it even clearer that it does not limit the freedom of a union to try to induce an employer to select a particular § 302 (c) (5) trustee.
  Congress enacted §8 (b)(1)(B) largely to prevent unions from forcing employers to join multiemployer bargaining units, or to dictate the identity of those who would represent employers in collective-bargaining negotiations or the settlement of employee grievances. See American Broadcasting Cos. v. Writers Guild, 437 U. S. 411, 422-423, 429-431, 435-436; Florida Power & Light Co. v. Electrical Workers, 417 U. S. 790, 803; S. Rep. No. 105, 80th Cong., 1st Sess., pt. 1, p. 21, (1947), 1 Leg. Hist. LMRA, at 427; 93 Cong. Rec. 4143 (1947) (Sen. Ellender). The legislative history reveals the concern of some Senators that if unions could strike or bargain to impasse to compel employers to join industrywide bargaining units, the large unions might exercise monopoly power over wages or call strikes threatening large portions of the national economy. S. Rep. No. 105, pt. 1, supra, at 51, 1 Leg. Hist. LMRA, at 457; 93 Cong. Rec. 4582-4588 (1947) (Sen. Taft). However, the power of a union to strike or bargain to impasse to induce an employer to contribute to a multiemployer trust fund does not pose the danger Congress sought to prevent. Congress treated the issues of multiem-ployer bargaining units and multiemployer trust funds quite distinctly. It is permissible under the law, and may be in the interest of the public, for an employer to bargain separately with a union, independently of any industrywide employer association, while the union exerts economic pressure to obtain protection for the employees through the medium of a multiemployer benefit fund.
  Moreover, union pressure to force an employer to contribute to an established employee trust fund does not amount to dictating to an employer who shall represent him in collective bargaining and the adjustment of grievances, because the trustees of a § 302 (c) (5) trust fund simply do not, as such, engage in these activities. The term “collective bargaining” in § 8 (b) (1) (B) of the Act is defined by § 8 (d):
  “[T]he performance of the mutual obligation of the employer and the representative of the employees to meet at reasonable times and confer in good faith with respect to wages, hours, and other terms and conditions of employment, or the negotiation of an agreement, or any question arising thereunder, and the execution of a written contract incorporating any agreement reached if requested by either party, but such obligation does not compel either party to agree to a proposal or require the making of a concession 29 U. S. C. § 158 (d).
  Under this definition, the collective-bargaining representatives of an employer and a union attempt to reach an agreement by negotiation, and, failing agreement, are free to settle their differences by resort to such economic weapons as strikes and lockouts, without any compulsion to reach agreement. See Carbon Fuel Co. v. Mine Workers, 444 U. S. 212, 219; NLRB v. Insurance Agents, 361 U. S. 477, 495.
  The atmosphere in which employee benefit trust fund fiduciaries must operate, as mandated by § 302 (c) (5) and ERISA, is wholly inconsistent with this process of compromise and economic pressure. The management-appointed and union-appointed trustees do not bargain with each other to set the terms of the employer-employee contract; they can neither require employer contributions not required by the original collectively bargained contract, nor compromise the claims of the union or the employer with regard to the latter’s contributions. Rather, the trustees operate under a detailed written agreement, 29 U. S. C. § 186 (c) (5) (B), which is itself the product of bargaining between the representatives of the employees and those of the employer. Indeed, the trustees have an obligation to enforce the terms of the collective-bargaining agreement regarding employee fund contributions against the employer “for the sole benefit of the beneficiaries of the fund.” United States v. Carter, 353 U. S. 210, 220. Finally, disputes between benefit fund trustees over the administration of the trust cannot, as can disputes between parties in collective bargaining, lead to strikes, lockouts, or other exercises of economic power. Rather, whereas Congress has expressly rejected compulsory arbitration as a means of resolving collective-bargaining disputes, § 302 (c) (5) explicitly provides for the compulsory resolution of any deadlocks among welfare fund trustees by a neutral umpire. Compare 29 U. S. C. § 158 (d) with 29 U. S. C. § 186 (c) (5); see. n. 12, supra.
  Like collective bargaining, the adjustment of grievances concerns the relationship between employer and employee. See 29 U. S. C. § 159 (a). The trustees’ concern, however, is the relationship between the beneficiaries and the fund. The only “grievances” it may adjust are those concerning the eligibility of employees or their dependents for participation in the benefits of the fund. See Chemical Workers v. Pittsburgh Plate Glass Co., 404 U. S. 157, 164-171. And whereas Congress has adopted the principle of voluntary settlement, free of governmental compulsion, in the adjustment of employee grievances against the employer, § 203 (d) of the Act, 29 U. S. C. § 173 (d), a trustee deadlock over eligibility matters, like any other deadlock, must be submitted to the compulsory resolution procedure established by § 302 (c)(5).
  “Both the language and the legislative history of § 8 (b) (1)(B) reflect a clearly focused congressional concern with the protection of employers in the selection of representatives to engage in two particular and explicitly stated activities, namely collective bargaining and the adjustment of grievances.” Florida Power & Light Co. v. Electrical Workers, 417 U. S., at 803. The duties of an employer-appointed trustee of an employee benefit trust fund, under § 302 (c) (5) of the Act, under principles long ago developed in the courts of chancery, and under the specific provisions of ERISA, are totally alien to both of these activities. The Court of Appeals, therefore, was mistaken in believing that the conduct of the union in this case violated the provisions of §8 (b)(1)(B).
  For the reasons stated, the judgment of the Court of Appeals is reversed, and the cases are remanded for proceedings consistent with this opinion.
  It is so ordered.
  29 U. S. C. § 141 et seq.
  29 U. S. C. §158 (b)(1)(B).
  29 U. S. C. §186 (c)(5).
  The trust agreement sets out the health and retirement benefits provided to employees and their dependents, defines the terms and the responsibilities of the trustees, describes the method of administration of the trust, and provides for periodic audits, reports, and notices. The agree-inent also fixes the employers’ contributions to the trust, requiring a specified number of cents per ton of coal produced, with the one exception that the trustees themselves retain the power to fix the rate for coal salvaged from slurry, sludge, or other refuse.
  29 U. S. C. §158 (b)(3).
  On other claims by Amax, the Board found that the union had not bargained in bad faith in violation of § 8 (b) (3), but that the union had acted illegally in attempting to coerce Amax to join the multiemployer bargaining unit for the western mines, in failing to notify the Federal Mediation and Conciliation Service of its dispute with Amax before striking, and by insisting to impasse on certain contract proposals that would have violated § 8 (e) of the Act, 29 U. S. C. § 158(e). The Court of Appeals affirmed all these rulings, and they are not before this Court.
  The Board relied on its earlier resolution of this same issue in Sheet Metal Workers’ International Assn. and Edward J. Carlough (Central Florida Sheetmetal Contractors Assn., Inc.), 234 N. L. R. B. 1238 (1978).
  29 U. S. C. §186 (a).
  Trust funds may pay only “for medical or hospital care, pensions on retirement or death of employees, compensation for injuries or illness resulting from occupational activity or insurance to provide any of the foregoing, or unemployment benefits or life insurance, disability and sickness insurance, or accident insurance.” 29 U. S. C. § 186 (c)(5)(A).
  29 U. S. C. §186 (e)(5)(B).
  29 U. S. C. §186 (c)(5)(C).
  If the trustees deadlock over a matter of trust administration, the statute further provides that the trustees may select a neutral arbiter, or “in event of their failure to agree within a reasonable length of time, an impartial umpire to decide such dispute shall, on petition of either group, be appointed by the district court of the United States for the district where the trust fund has its principal office . . . .” 29 U. S. C. §186 (c)(5)(B).
  The use of the word “representatives” in §302 (c)(5)(B) in no way suggests that Congress did not intend to incorporate the equitable principles of fiduciary duty. The requirement that employer and employee be equally represented among the trustees of an employee benefit fund prevents any misuse of those funds by union officers who would otherwise have sole control of vast amounts of money contributed by the employer. See Arroyo v. United States, 359 U. S. 419, 425-426. The management-appointed trustee “represents” the employer only in the sense that he ensures that the union-appointed trustee does not abuse his trust with respect to the funds contributed by the employer. Nowhere in the debates over § 302 (c) (5) did any Member of either House of Congress suggest that the employer “representative” as a trustee of a benefit fund created under this statute could or should advance the interest of the employer in administering the fund. In fact, some opponents of the provision objected that the requirement of equal management-union representation imposed onerous administrative duties on the employers. E. g., 93 Cong. Rec. 4749 (1947) (Sen. Murray).
  The legislative history of § 302 (c) (5) also bears directly on the actual question underlying the statutory issue in this litigation: whether Congress intended to prohibit union demands for employer participation in established multiemployer trust funds. One of the events that greatly influenced the legislative efforts culminating in the Act was the demand of John L. Lewis, then head of the United Mine Workers, that all mine owners contribute 10 cents per ton of coal produced into a central welfare fund established by the union itself. United States v. Ryan, 350 U. S. 299, 304-305; S. Rep. No. 105, 80th Cong., 1st Sess., pt. 1, p. 52 (1947), 1 Leg. Hist. LMRA, at 458. The debates and Reports reveal that despite considerable congressional opposition to Lewis’ demands, ibid.; 93 Cong. Rec. 3423, 3516-3517, 3564-3565 (1947) (remarks of Reps. Hartley, Fisher, and Case) ; id., at 4678, 4746-4748 (Sens. Byrd and Taft), Congress specifically rejected proposals that would have rendered those demands illegal either by providing that union proposals concerning pension welfare benefits were not mandatory subjects of bargaining, or by prohibiting all such funds even indirectly established or managed by a union. See H. R. 3020, 80th Cong., 1st Sess., §§2(11), 8 (a) (2) (C) (ii) (1947), 1 Leg. Hist. LMRA, at 39-40, 51; H. R. Rep. No. 245, 80th Cong., 1st Sess., 14-17 (1947), 2 Leg. Hist. LMRA, at 305-308.
  A “participant” is “any employee or former employee . . . who is or may become eligible to receive a benefit of any type from an employee benefit plan ... , or whose beneficiaries may be eligible to receive any such benefit.” 29 U. S. C. § 1002 (7). A “beneficiary” is “a person designated by a participant, or by the terms of an employee benefit plan, who is or may become entitled to a benefit thereunder.” 29 U. S. C. § 1002 (8).
  Although § 408 (c) (3) of ERISA permits a trustee of an employee benefit fund to serve as an agent or representative of the union or employer, that provision in no way limits the duty of such a person to follow the law’s fiduciary standards while he is performing his responsibilities as trustee.
  In 1980, Congress amended ERISA to impose new responsibilities upon the trustees of multiemployer trust funds, passing the Multiemployer Pension Plan Amendments Act of 1980, Pub. L. 96-364, 94 Stat. 1209, which reaffirmed that the trustees must act solely in the interest of the trust beneficiaries, see H. R. Rep. No. 96-869, pt. 1, p. 67 (1980).
  Neither statutory provision refers to the other, and though the same congressional Committees considered the issues of employee benefit trust funds and multiemployer bargaining, the legislative history nowhere suggests that Congress intended that the restrictions on union activity created by § 8 (b) (1) (B) were relevant to the selection of § 302 (c) (5) trustees. Indeed, though faced with a United Mine Workers demand that owners contribute a fixed percentage of their coal receipts to a multiemployer trust fund created by the union, Congress rejected several proposals that would have denied the union the power to make such demands. See n. 14, swpra.
  Another concern of § 8 (b)(1)(B), of no relevance here, was to prevent a union from striking to force an employer to fire a supervisor who, in the union’s view, was too stern in his treatment of employees. 93 Cong. Rec. 3837-3838 (1947) (Sen. Taft).
  The sole and minor exception under the agreement governing the national trust funds in this litigation is the authority of the trustees to fix the number of cents per ton of salvage coal produced which a mine operator must contribute to the funds. See n. 4, supra.
  If the administration of § 302 (c) (5) trust funds were “collective bargaining” within the meaning of federal labor law, as it would be under the Court of Appeals’ view, the NLRB would have to review the discretionary-actions of the trustees according to the statutory duty of good-faith bargaining. 29 U. S. C. §§158 (a) (5), (b)(3), (d). The Board would thereby be thrust “into a new area of regulation which Congress [has] not committed to it,” NLRB v. Insurance Agents, 361 U. S. 477, 499. Moreover, under the Court of Appeals’ view, a trustee would be subject to simultaneous regulation by the Board, the Secretary of Labor, and the courts, and might be tom between conflicting duties imposed by the National Labor Relations Act and ERISA. For example, ERISA requires a trustee to prevent any other trustee from breaching his fiduciary responsibilities to the trust beneficiaries. 29 U. S. C. §§ 1105 (a) (3), (b) (1) (A). On the other hand, § 8 (b) (1) (B) bars a union representative from interfering with the employer’s collective-bargaining agent’s performance of his duties in accordance with the employer’s instructions. American Broadcasting Cos. v. Writers Guild, 437 U. S. 411, 436. Therefore, if trust fund administration is collective bargaining, a trustee could be charged with an unfair labor practice by carrying out his duties under ERISA.
  The view of the Court of Appeals that the union could not seek to compel the employer to join an established employee trust fund conflicts with recent legislation concerning multiemployer pension plans. In this litigation, Amax claimed complete power under §8 (b)(1)(B), unaffected by union economic pressure, to select the sole trustee, or all the trustees, of the trust fund benefiting the Belle Ayr Mine employees. Since, by definition, it is impossible for every employer participating in a multi-employer trust fund to exercise such power, the Court of Appeals’ decision upholding Amax’s claim would effectively preclude a union from resorting to economic pressure to cause an employer to participate in a multiemployer trust fund. Congress amended ERISA in 1980 to strengthen the funding requirements and enhance the financial stability of multiemployer pension plans. In these amendments, Congress sought to foster “the maintenance and growth of multiemployer pension plans . . . [and] to provide reasonable protection for the interests of the participants and beneficiaries of financially distressed multiemployer pension plans.” §§ 3 (c) (2) and (c) (3) of the Multiemployer Pension Plan Amendments Act of 1980, Pub. L. 96-364, 94 Stat. 1209-1210. Section 3(a)(4)(A) of the 1980 Act states that “withdrawals of contributing employers from a multiemployer pension . . . adversely [affect] the plan, its participants and beneficiaries, and labor-management relations. . . .” 94 Stat. 1209. The Court of Appeals’ decision therefore runs afoul of express congressional policy favoring multiemployer trusts.