In the

United States Court of Appeals

For the Seventh Circuit ____________________ 

No. 21-1794 

RIVERSTONE GROUP, INC., 

Plaintiff/Counter Defendant-Appellee, 

v.

MIDWEST OPERATING ENGINEERS

FRINGE BENEFIT FUNDS, 

Defendant/Counter Plaintiff-Appellant. 

____________________ 

Appeal from the United States District Court for the

Central District of Illinois. 

No. 4:19-cv-04039 — Sara Darrow, Chief Judge. 

____________________ 

ARGUED DECEMBER 6, 2021 — DECIDED MAY 4, 2022 

____________________ 

Before RIPPLE, WOOD, and KIRSCH, Circuit Judges. 

RIPPLE, Circuit Judge. RiverStone Group, Inc. (“RiverStone”) filed this action seeking a declaratory judgment, see 

28 U.S.C. § 2201, that it had no obligation to make contributions to the employees’ pension fund on behalf of individuals 

hired after the collective bargaining agreement had expired. 

The defendant, Midwest Operating Engineers Fringe Benefit 

Funds (“the Funds”), filed a counterclaim, seeking an 
2 No. 21-1794 

accounting and payment of the contributions that, in their 

view, RiverStone owed on behalf of these new employees. In 

due course, the parties filed cross-motions for summary judgment. The district court granted RiverStone’s motion; it held 

that RiverStone did not have a contractual duty to contribute 

to the Funds on behalf of the new employees and that it lacked 

jurisdiction to evaluate noncontractual sources of liability, 

such as the National Labor Relations Act (“NLRA”). Therefore, the dispute fell within the exclusive jurisdiction of the 

National Labor Relations Board (“NLRB”). The Funds timely 

appealed.1

Because we agree with the district court that this matter 

falls within the exclusive province of the NLRB, we affirm the 

decision of the district court.

I 

BACKGROUND

A.

RiverStone, a mining company, operates sand and stone 

quarries in three midwestern states. The International Union 

of Operating Engineers, Local 150 (“Local 150”), represented 

a bargaining unit of RiverStone employees. Under the collective bargaining agreement, RiverStone contributed to the 

Funds based upon hours worked by the members of the bargaining unit. 

The collective bargaining agreement expired on May 1, 

2016. No language in the agreement imposes on RiverStone 

an obligation to make contributions after the agreement’s 

1 Our appellate jurisdiction is secure under 28 U.S.C. § 1291.
No. 21-1794 3

expiration. RiverStone and Local 150 tried unsuccessfully to 

negotiate a successor agreement but were unable to come to 

mutually acceptable terms. However, the parties did not 

reach an “impasse,” as that term is employed in the federal 

labor law context.2 After the agreement expired, RiverStone 

continued to contribute to the Funds on behalf of the members of the bargaining unit. 

On March 20, 2018, Local 150 went on strike, claiming that 

RiverStone had committed unfair labor practices; the union 

also filed charges with the NLRB.3 At that point, RiverStone 

stopped making contributions to the Funds on behalf of the 

striking employees. 

2 The Supreme Court described an “impasse” in these terms: “that point 

at which the parties have exhausted the prospects of concluding an agreement and further discussions would be fruitless.” Laborers Health & Welfare 

Tr. Fund for N. Cal. v. Advanced Lightweight Concrete Co., 484 U.S. 539, 543 

n.5 (1988) (quoting Laborers Health & Welfare Tr. Fund for N. Cal. v. Advanced 

Lightweight Concrete Co., 779 F.2d 497, 500 n.3 (9th Cir. 1985)). 

3 An administrative law judge for the NLRB found that RiverStone had 

violated the NLRA by changing its “punch-in policy” without bargaining 

with Local 150, by requiring strikers to sign a preferential hiring list in 

order to return to work, by removing picket signs from public property, 

by disciplining and discharging an employee for engaging in union activity, and by denying an employee’s right to union representation during 

an investigatory interview. See Troy Grove, a Div. of Riverstone Grp. Inc., 

Case No. 25-CA-234477, 2021 WL 86882 (N.L.R.B. Div. of Judges Jan. 11, 

2021). 
4 No. 21-1794 

During the strike, RiverStone hired new employees.4

These new employees did the same work as that performed 

previously by striking employees, but RiverStone did not 

make contributions to the Funds on their behalf. In the summer of 2018, some striking employees began to make unconditional offers to return to work; as they did, they were reinstated and contributions on their behalf resumed.

B.5

1. 

On February 12, 2019, the Funds asserted in an audit letter 

that RiverStone owed the Funds $243,882.40 in benefit contributions on behalf of the new employees. After receiving the 

letter, RiverStone filed this action in the district court, seeking 

a declaratory judgment that it did not owe the payments 

sought by the Funds. RiverStone asserted that the district 

4 The parties dispute whether these new employees were “permanent replacements.” Compare R.1 at 2, with R.20 at 2. Answering this question is 

outside the scope of this case. We will call the employees hired during the 

strike the “new employees” and the ones hired before the strike the “striking employees.”

5 This case involves three statutes and several acronyms and initialisms. 

For clarity, we will use the following nomenclature:

• Section 301 of the Taft-Hartley Act, also known as the Labor Management Relations Act, is referred to as LMRA § 301. LMRA § 301 

is codified at 29 U.S.C. § 185(a). 

• Section 8 of the National Labor Relations Act is NLRA § 8(a)(5), 

and the Act itself is referred to as the NLRA. This Section is codified at 29 U.S.C. § 158(a)(5).

• Section 515 of the Employee Retirement Income Security Act

(“ERISA”) is ERISA § 515, codified at 29 U.S.C. § 1145.
No. 21-1794 5

court had subject matter jurisdiction under LMRA § 301(a) because “the parties’ dispute involves a purported obligation 

arising from the [collective bargaining agreement].”6 It further asserted that there was no obligation “arising from the 

[collective bargaining agreement] that requires RiverStone to 

make contributions to the Fund on behalf of Permanent Replacements whose wages, hours, terms and conditions of employment do not arise from the [collective bargaining agreement].”7

 

The Funds filed a motion to dismiss, submitting that 

LMRA § 301 could not serve as a predicate for the district 

court’s subject matter jurisdiction because the Funds are not a 

labor organization and because the complaint contained no 

allegation of a contract violation. They maintained that the 

district court’s jurisdiction was preempted by the NLRA because RiverStone was, in essence, claiming that it had no obligation to negotiate with Local 150 about its refusal to contribute for new employees. Such a dispute, in the Funds’ view, 

should have been brought before the NLRB, not the district 

court. 

In deciding the motion to dismiss, the district court held 

that it had subject matter jurisdiction over the declaratory 

judgment action. It reasoned that LMRA § 301 permits a fund 

to sue an employer for breach of a collective bargaining agreement, and therefore the statute also permits an employer to 

bring a declaratory judgment action against a fund to 

6 R.1 at 2. 

7 Id. at 3. 
6 No. 21-1794 

determine its rights and obligations under such an agreement.8 The district court further held that the NLRB did not 

have exclusive jurisdiction over the dispute. Because the controversy involves a breach of a collective bargaining agreement, wrote the court, LMRA § 301 gave the court at least concurrent jurisdiction.

8 LMRA § 301 provides jurisdiction for fund trustees to sue an employer 

for contributions under a contract. See Kaiser Steel Corp. v. Mullins, 455 U.S. 

72, 76, 83–84 (1982). In turn, under the inverse well-pleaded complaint rule 

of declaratory judgments, see NewPage Wisconsin Sys. Inc. v. United Steel, 

Paper & Forestry Workers Int’l Union, 651 F.3d 775, 777–78 (7th Cir. 2011), 

an employer can invoke Section 301 in a declaratory judgment action to 

determine whether it violated a collective bargaining agreement, see Michels Corp. v. Cent. States, Se., & Sw. Areas Pension Fund, 800 F.3d 411, 415–

16 (7th Cir. 2015). 

Although a Section 301 suit can be brought only against the parties to 

the contract, see Loss v. Blankenship, 673 F.2d 942, 946 (7th Cir. 1982); Baker 

v. Fleet Maint., Inc., 409 F.2d 551, 554 (7th Cir. 1969), we have long recognized that trust fund beneficiaries can sue under Section 301 as third-party 

beneficiaries to the agreement, see, e.g., Lewis v. Quality Coal Corp., 243 F.2d 

769, 772–73 (7th Cir. 1957); Bugher v. Feightner, 722 F.2d 1356, 1358 (7th Cir. 

1983) (“[P]lan trustees are considered to be third party beneficiaries of the 

collective bargaining agreement between the union and the employer. In 

that capacity, the trustees can bring an action [under LMRA § 301] seeking 

damages for breach of contract ... .”); Laborers’ Pension Fund v. Blackmore 

Sewer Constr., Inc., 298 F.3d 600, 602 (7th Cir. 2002); Chi. Painters & Decorators Pension, Health & Welfare & Deferred Sav. Plan Tr. Funds v. Karr Bros., 

755 F.2d 1285, 1287–88 (7th Cir. 1985); Chi. Reg’l Council of Carpenters Pension Fund v. Schal Bovis, Inc., 826 F.3d 397, 399–400 (7th Cir. 2016); McCleskey v. CWG Plastering, LLC, 897 F.3d 899, 901 (7th Cir. 2018); see also Kaiser 

Steel Corp., 455 U.S. at 83 n.8; Loss, 673 F.2d at 948. Because they can be 

sued by fund trustees for breach, employers can seek a declaratory judgment determining whether they are in breach.
No. 21-1794 7

2. 

Relying on ERISA § 515 and LMRA § 301, the Funds then 

filed a counterclaim, asserting a right to an audit and to payment of contributions from RiverStone to the Funds on behalf 

of the new employees. In due course, RiverStone moved for 

summary judgment on its declaratory judgment request and 

on the Funds’ ERISA-based counterclaim. RiverStone raised 

labor law defenses, not relevant to this appeal, and submitted 

that because the collective bargaining agreement had expired, 

it had no obligation to contribute on behalf of the new employees. 

In replying to RiverStone’s motion for summary judgment, the Funds characterized the dispute as a simple ERISA 

case and maintained that RiverStone owed contributions for 

bargaining unit employees based on the hours they had 

worked and the wages they were paid. It also contended that, 

absent an impasse, RiverStone was required by NLRA 

§ 8(a)(5) to maintain the status quo by making the disputed 

contributions. In the Funds’ view, RiverStone’s failure to 

make these contributions on behalf of the new employees, regardless of whether they were permanent replacements, altered the status quo.

The district court entered summary judgment for RiverStone. It acknowledged its authority to construe a collective 

bargaining agreement and further acknowledged that a collective bargaining agreement could serve as the predicate for 

ERISA liability. But, here, it continued, the collective bargaining agreement had expired and therefore could not serve as 

such a predicate. The sine qua non for liability under ERISA 

§ 515, the court emphasized, is the existence of a valid written 

instrument binding the employer to make the payments. 
8 No. 21-1794 

Although the district court had full authority to hear an 

ERISA case, it did not have jurisdiction to resolve claims of 

unpaid contributions when no contractual provision applied. 

Relying on Laborers Health & Welfare Trust Fund for Northern 

California v. Advanced Lightweight Concrete Co., 484 U.S. 539, 

548–49 (1988), the district court concluded that “[a]fter a [collective bargaining agreement] or other relevant agreement expires, an employer’s obligation under ERISA to pay contributions pursuant to that agreement ceases.”9

Without a contract, 

concluded the court, any failure to make payments “could 

only constitute a violation of NLRA § 8(a)(5),”10 which is under the NLRB’s exclusive jurisdiction. 

The court therefore determined that there could be no 

duty under ERISA without a contractual provision and declared that “RiverStone has no duty to make contributions to 

the Funds on behalf of the new employees pursuant to the 

[collective bargaining agreement] or the Trust Agreements.”11

Finally, the district court noted that, in their counterclaim, the 

Funds had sought relief under NLRA § 8(a)(5), but it ruled 

that such claims were within the exclusive purview of the 

NLRB. 

9 R.53 at 6.

10 Id. at 8.

11 Id. at 13.
No. 21-1794 9

II

DISCUSSION

A.

At this point in the litigation, the Funds maintain RiverStone’s refusal to make payments to the Funds for the new 

employees violates the company’s continuing obligation to 

maintain the status quo while the parties continue to negotiate a new agreement. See NLRB v. Katz, 369 U.S. 736, 743 

(1962). Given its authority to construe labor contracts in accordance with national labor policy grounded in the LMRA, 

see Textile Workers Union v. Lincoln Mills of Alabama, 353 U.S. 

448, 456 (1957), the district court should have viewed this obligation to maintain the status quo as federal labor policy and 

enforced it as an obligation of RiverStone. Relying on Lincoln 

Mills, the Funds submit that it was well within the permissible 

“range of judicial inventiveness” of the LMRA to apply the 

status quo preservation rule12 derived from the NLRB’s jurisprudence of unfair labor practices in the context of Section 

301.13

In the alternative, the Funds submit that the district court 

should have assumed jurisdiction under Sections 502 and 515 

of ERISA, 29 U.S.C. §§ 1132, 1145, because the Funds have an 

independent right to enforce the terms of the collective bargaining agreement relating to the funding of benefits. See 

Cent. States, Se. & Sw. Areas Pension Fund v. Gerber Truck Serv., 

12 The requirement to maintain the status quo stems from the statutory 

duty to bargain. See NLRB v. Katz, 369 U.S. 736, 743 (1962); see also 29 U.S.C. 

§ 158(a)(5).

13 Appellant’s Br. 19.
10 No. 21-1794 

870 F.2d 1148 (7th Cir. 1989) (en banc). The new employees 

were, emphasize the Funds, employees of RiverStone and 

performing bargaining unit work. Therefore, RiverStone was 

obligated to contribute to the Funds on their behalf. 

RiverStone maintains that no contractual provision is implicated because the contract had expired. Without a contractual provision to serve as a predicate, continues RiverStone, 

the sole possible legal ground left for relief is the NLRA. Because the NLRB has exclusive jurisdiction over NLRA disputes, the district court correctly ruled that it was without jurisdiction. 

B.

We begin our analysis by examining the statutory landscape. Central to the federal regulation of industrial relations 

affecting interstate commerce is the NLRA. This statute 

makes it unlawful for an employer “to refuse to bargain collectively with the representatives of his employees.” 29 U.S.C. 

§ 158(a)(5). As part of this duty to bargain, an employer must 

“maintain the status quo after the expiration of a collective 

bargaining agreement until a new agreement is reached or 

until the parties bargain in good faith to impasse.” Gen. Serv. 

Emps. Union, Loc. 73 v. NLRB, 230 F.3d 909, 913 (7th Cir. 2000) 

(quoting NLRB v. Emsing’s Supermarket, 872 F.2d 1279, 1285 

(7th Cir. 1989)); Katz, 369 U.S. at 743 (“We hold that an employer’s unilateral change in conditions of employment under 

negotiation is similarly a violation of § 8(a)(5), for it is a circumvention of the duty to negotiate which frustrates the objectives of § 8(a)(5) much as does a flat refusal.”). 

“As a general rule, federal courts do not have jurisdiction 

over activity which ‘is arguably subject to ... § 8 of the 
No. 21-1794 11

[NLRA],’ and they ‘must defer to the exclusive competence of 

the National Labor Relations Board.’” Kaiser Steel Corp. v. Mullins, 455 U.S. 72, 83 (1982) (alteration in original) (quoting San 

Diego Bldg. Trades Council v. Garmon, 359 U.S. 236, 245 (1959)). 

There is, however, an exception pertinent to our case. LMRA 

§ 301 vests the district courts with concurrent authority to entertain “[s]uits for violation of contracts between an employer 

and a labor organization representing employees in an industry affecting commerce.” 29 U.S.C. § 185(a). Section 301 provides an “extremely limited” grant of jurisdiction only for 

“cases that allege violations of the collective bargaining agreement.” Teamsters Nat’l Auto. Transporters Indus. Negotiating 

Comm. v. Troha, 328 F.3d 325, 329 (7th Cir. 2003); Textron Lycoming Reciprocating Engine Div. v. United Auto. Workers, Int’l 

Union, 523 U.S. 653, 661–62 (1998); see also Miner v. Loc. 373, 

513 F.3d 854, 860 (8th Cir. 2008) (“The existence of a valid contract between an employer and a labor organization is a necessary prerequisite for federal jurisdiction under Section 

301(a).”). 

ERISA supplies the final statutory landmark. Section 515 

of this statute, 29 U.S.C. § 1145, imposes an affirmative obligation on employers to make contributions to multiemployer 

benefits plans in accordance with the terms of the plan or the 

governing collective bargaining agreement. Another section 

of the same statute, Section 502, 29 U.S.C. § 1132(g)(2), permits 

a “fiduciary for or on behalf of plan” to bring an action in the 

district court to compel such payments. If the employer is 

found to be delinquent in its payments, the court may award 

not only the unpaid contributions but also interest on those 

unpaid contributions and liquidated damages at least equal 

to the amount of that interest. Attorney’s fees, costs and “such 
12 No. 21-1794 

other legal or equitable relief as the court deems appropriate” 

are also available. Id. 

The Supreme Court has spoken on the interaction between 

ERISA and federal labor policy under the NLRA in Advanced 

Lightweight Concrete. The Supreme Court held that once a collective bargaining agreement had expired, ERISA did not confer jurisdiction on the district court to determine whether the 

employer’s failure to make post-contract contributions violated the NLRA. Advanced Lightweight Concrete, 484 U.S. at 

547–49. There, the fund, alleging a breach of the employer’s

duty to bargain in good faith under NLRA § 8(a)(5) and asserting jurisdiction under ERISA § 515, id. at 542–43, sued the 

employer to collect post-contract contributions. The fund contended that the court should give ERISA “§ 515 a broad construction that would include postcontract delinquencies” because to hold otherwise would leave a “gap” in the enforcement scheme. Id. at 550–51. 

The Supreme Court ruled that the fund was not entitled to 

relief under ERISA. It held that the duty to maintain the status 

quo after the expiration of the collective bargaining agreement derives from NLRA § 8(a)(5)—not the collective bargaining agreement. “If the labor legislation were simply repealed, in toto, [the funds] would have no basis whatsoever 

for claiming that an employer had any duty to continue making contributions to [the funds] after the expiration of its contractual commitment to do so.” Id. at 553. Therefore, the NLRB 

has the exclusive authority to determine whether the employer has violated that duty. Id. at 552. The Court reasoned 

that nothing in ERISA “confer[ed] jurisdiction on district 

courts to determine whether an employer’s unilateral decision to refuse to make postcontract contributions constitutes 
No. 21-1794 13

a violation of the NLRA.” Id. at 549. The Court then explained 

that there were strong policy reasons against reading the 

ERISA statute so broadly as to confer jurisdiction over an alleged violation of the NLRA: 

[W]hether an employer’s unilateral decision to 

discontinue contributions to a pension plan constitutes a violation of the statutory duty to bargain in good faith is the kind of question that is 

routinely resolved by the administrative agency 

with expertise in labor law. There are situations 

in which district judges must occasionally resolve labor issues, but they surely represent the 

exception rather than the rule. In cases like this, 

which involve either an actual or an “arguable” 

violation of § 8 of the NLRA, federal courts typically defer to the judgment of the NLRB.

Id. at 552.

14 

C.

Unable to bring an action based on the ERISA statute because of the Supreme Court’s decision in Advanced Lightweight 

Concrete, the Funds attempt to avoid that barrier by premising 

their action for the payment of contributions on LMRA § 301. 

In essence, they maintain that federal courts can develop 

through LMRA § 301 a federal common law obligation to bestow the benefits of an expired collective bargaining agreement on workers hired after that expiration.

14 We have decided in Stone v. Signode Industrial Group LLC, 943 F. 3d 381 

(7th Cir. 2019) that the parties to a contract are free to provide that those 

benefits will survive the underlying agreement.
14 No. 21-1794 

The district court correctly concluded that Advanced Lightweight Concrete precludes such an intrusion into the domain 

of the unfair labor practices provision of NLRA § 8(a)(5). In 

the absence of a contractual provision, whether the duty to 

preserve the status quo extends to contributions of newly 

hired workers is an issue for the NLRB. Consequently, the district court correctly held that it lacked “jurisdiction to resolve 

claims of unpaid contributions when no contractual provision[] applies.”15

Moreover, this conclusion is consonant with the Supreme 

Court’s description of the relationship between NLRA § 8 and 

LMRA § 301: 

When an activity is ... arguably prohibited by 

§ 8 of the NLRA, the preemption doctrine developed in [Garmon], and its progeny, teaches that 

ordinarily “the States as well as the federal 

courts must defer to the exclusive competence 

of the National Labor Relations Board if the 

danger of state interference with national policy 

is to be averted.” When, however, the activity in 

question also constitutes a breach of a collectivebargaining agreement, the Board’s authority “is 

not exclusive and does not destroy the jurisdiction of the courts in suits under § 301.” 

William E. Arnold Co. v. Carpenters Dist. Council, 417 U.S. 12, 

15–16 (1974) (cleaned up) (first quoting Garmon, 359 U.S. at 

245; and then quoting Smith v. Evening News Ass’n, 371 U.S 

195, 197 (1962)). The Funds do not argue that RiverStone 

15 R.53 at 7.
No. 21-1794 15

breached the collective bargaining agreement—instead they 

argue that “labor law” requires “employers [to] honor the 

terms of an expired agreement.”16 This is an NLRA § 8(a)(5) 

argument, not an LMRA § 301 argument. It should thus be 

brought to the NLRB.

The Funds nevertheless submit that “[u]nder Lincoln Mills, 

it was well within the Court’s ‘range of judicial inventiveness’ 

to apply the NLRB’s rule endorsed by the Supreme Court in 

Katz and Advanced Lightweight to enforce RiverStone’s admitted obligation to maintain the [collective bargaining agreement’s] terms and submit contributions to the Funds.”17 They 

remind us that the Supreme Court has indicated that federal

courts can develop federal common law to effectuate the goals 

of LMRA § 301 and that this authority includes solving the 

“problems [that] lie in the penumbra of express statutory 

mandates. Some will lack express statutory sanction but will 

be solved by looking at the policy of the legislation and fashioning a remedy that will effectuate that policy.” Lincoln Mills, 

353 U.S. at 457. Judges are allowed a “range of judicial inventiveness ... determined by the nature of the problem.” Id.

We cannot construe this latitude as permission to go beyond the focused task of construing a labor contract and to 

invade the exclusive province of the NLRB. Cf. Textron, 

523 U.S. at 657 (“‘Suits for violation of contracts’ under 

§ 301(a) are ... suits that claim a contract has been violated.”). 

“Judicial inventiveness” must be limited to those matters directly tied to the enforcement of labor contracts. For instance, 

16 Appellant’s Br. 17.

17 Id. at 19. 
16 No. 21-1794 

in Troha, we held LMRA § 301 permits a party to a collective 

bargaining agreement that is otherwise covered by § 301 to 

enforce an arbitration subpoena against a non-signatory of the 

agreement. 328 F.3d at 331. We concluded that federal question jurisdiction was proper, following two veins of reasoning: first, the federal cause of action was necessary to effectuate the collective bargaining agreement. Id. at 330 (“Enforcement of an agreement to arbitrate cannot provide the ‘necessary legal remedy’ if the parties to the arbitration have no 

means of securing valuable evidence other than their own testimony.”). Second, a parallel statute, the Federal Arbitration 

Act, suggested a congressional desire to have an enforcement 

mechanism for arbitration subpoenas. Id. at 330–31. 

Both rationales for finding a federal cause of action in 

Troha counsel against finding one here. First, a federal cause 

of action is not necessary to effectuate § 301; NLRA § 8(a)(5) 

already handles this exact situation. There is no gap in the 

statutory scheme that requires judicial inventiveness. The dispute falls squarely—but only—into NLRA § 8. Second, employing Section 301 here would not effectuate the congressional regulation of labor relations; Congress already has 

vested this task in the NLRB through NLRA § 8. 

The Funds rely on two other cases in support of their position. Neither is controlling; neither requires extended discussion. Midwest Operating Engineers Welfare Fund v. Cleveland 

Quarry, 844 F.3d 627 (7th Cir. 2016), is of no help to the Funds. 

That case was solely concerned with “the contributions that 

RiverStone had failed to make in the interim between the decertification of the union and the expiration of the collective 

bargaining agreement,” not post-collective bargaining 
No. 21-1794 17

agreement contributions. Id. at 629. Unlike here, the contract 

was still intact. 

Nolde Bros. v. Local No. 358, Bakery & Confectionery Workers 

Union, 430 U.S. 243 (1977), is also of no help. It is a case involving an agreement to arbitrate disputes arising out of the 

contract. When the contract was terminated, the employer refused to arbitrate a dispute over severance payment rights 

earned under the contract. Id. at 246–48. Relying on its precedent, the Supreme Court explained that “obligations under 

their arbitration clause survived contract termination when 

the dispute was over an obligation arguably created by the 

expired agreement.” Id. at 252. Here, the dispute is over an 

obligation that does not arise under any contract. 

The remainder of the Funds’ arguments deal with alleged 

unfair labor practice matters properly within the domain of 

the NLRB. 

Conclusion

We affirm the judgment of the district court.

AFFIRMED