In the

United States Court of Appeals

For the Seventh Circuit

Nos. 99-3634, 99-3994

Naperville Ready Mix, Inc., et al.,

Petitioners/Cross-Respondents,

v.

National Labor Relations Board,

Respondent/Cross-Petitioner,

and

Teamsters Local 673,

Intervening Respondent/Cross-Petitioner.

On Petition for Review and Cross-Application

for Enforcement of an Order

of the National Labor Relations Board

Nos. 13-CA-31031, et al.

Argued September 28, 2000--Decided March 6, 2001

 Before Manion, Rovner, and Diane P. Wood, Circuit

Judges.

 Diane P. Wood, Circuit Judge. Richard Wehrli

owned several companies in Naperville, Illinois,

which were involved in the concrete and trucking

businesses. This case arose when one of the

companies, Naperville Ready Mix, Inc. (NRM),

decided to change the way that it would deliver

concrete. The National Labor Relations Board (the

Board) concluded that NRM and several other of

Wehrli’s companies were a single employer for

purposes of the labor laws, and it further found

that the company had violated various sections of

the National Labor Relations Act (the Act)

through its efforts to transfer bargaining unit

delivery work from employees to alleged

independent owner-drivers. NRM and its

affiliates, T&W Trucking, Inc. (T&W), and Wehrli

Equipment Co. (WEC), have asked us to set aside

the Board’s order requiring reinstatement of

certain drivers and restoration of the bargaining

unit work; the Board requests enforcement of its

order. We conclude that the Board’s order is

supported by substantial evidence and the law,

and we thus conclude that it is entitled to

enforcement.
I

 Wehrli incorporated NRM in 1960, with himself

and his wife Judith Wehrli as the only

stockholders. Wehrli served as NRM’s president,

and as of 1992 the company’s board consisted of

Richard and Judith Wehrli, Richard’s brother-inlaw Jerome Doll and the Wehrlis’ son Robert. In

1978, Wehrli incorporated WEC to provide repair

services for NRM dump trucks and other trucks at

NRM’s facility on High Grove Street in

Naperville. Wehrli is the sole shareholder of

WEC; he served on its board of directors through

1992, when he was replaced by his son Scott. In

1987, Wehrli and a supervisor at NRM, Robert

Tilly, added T&W trucking to the family of

companies. Through 1992, they were T&W’s sole

directors and shareholders. At the time of the

events relevant to this case, T&W was providing

hauling services for only two companies: NRM and

one other.

 Ready-mix truck drivers at NRM were covered by

a collective bargaining agreement that Wehrli had

originally negotiated with Teamsters Local 673

(the Union) in 1986. On April 21, 1992, NRM and

the Union began negotiating a successor agreement

for the one that was due to expire nine days

later, on April 30. The Union’s principal

representative was its Secretary-Treasurer, Tom

Custer, while Wehrli spoke for NRM. At the

initial meeting, the Union presented a

comprehensive written proposal seeking increased

wages and pension benefits as well as improved

job protection standards for the drivers. NRM

rejected the proposal and countered with a oneyear roll-over offer, with a few revisions to the

health and pension plan provisions. Wehrli argued

that concessions from the Union were necessary

because of increased competition and declining

profit margins in the ready-mix business. In the

absence of concessions, he warned, he would

either have to suspend trucking operations until

the market improved or get out of the hauling

business altogether. 

 When the parties met again on May 7, the Union

tried to take the contract items one-by-one. NRM

was not receptive to this tactic; Wehrli saw it

as a ploy by the Union to win benefits comparable

to those it had secured with the Northern

Illinois Ready Mix Association (NIRMA), a local

multi-employer bargaining group. Wehrli claimed

that NRM was losing money on the delivery portion

of its business, and he announced that he wanted

to sell NRM’s trucks and operate with owneroperator subcontractors. Custer responded by

saying that if NRM were to make such a move it

would have to become a party to the NIRMA
agreement (as other similarly situated companies

had done), which gave owner-operators the

protections of union membership. Custer also

commented that the Union was there to negotiate

a contract, not to help NRM sell its trucks. 

 On May 12, Wehrli sent Custer the following

letter:

 I have decided to go out of the trucking

business and am offering to sell my trucks to my

present drivers first, and then any leftover

trucks will be offered to outsiders. I intend to

use individual contractors for all my trucking

needs. If you want any discussion with me in this

regard feel free to call.

Custer saw this letter as a part of the overall

bargaining give-and-take, as it reflected the

position Wehrli had taken at the two previous

bargaining sessions. He therefore saw no need to,

and did not, specifically reply to the letter.

 The parties held another bargaining meeting on

May 14, at which they made some progress. The

Union agreed to remove certain demands, and NRM

agreed to modify the language in several contract

clauses. Wehrli continued to assert that he

intended to sell the trucks. To this end, he

introduced a proposal to delete Article 24 from

the contract. Article 24 provided that certain

owner-operator subcontractors would be treated

like bargaining unit employees for purposes of

wages, union security, and benefits. Wehrli

wanted it deleted because it would have defeated

much of the point of his plan to sell NRM’s

ready-mix trucks and to rely on subcontract

haulers. He made it clear that under his

proposal, the new subcontract haulers would not

be members of the NRM employee bargaining unit.

On May 15, he reduced his proposal to writing. 

 Without waiting for the Union’s response, Wehrli

proceeded to hold meetings with NRM’s drivers on

May 20 and May 27. The Union had no notice of

these meetings and did not approve them. At the

meetings, Wehrli discussed the financial

difficulties he faced and informed the drivers of

his intention to sell the trucks. He promised

that he would make the trucks available for

purchase by current drivers and that he would

assist them with the logistics of becoming owner

operators and with financing the purchase of the

trucks. Wehrli also stated as a fait accompli

that if the drivers became subcontractors they

would no longer be covered under the Union’s

contract with NRM. Finally, he informed the

drivers that as trucks were sold to current NRM

and outside drivers, current drivers who had not

purchased trucks would be laid off in reverse
order of seniority. 

 After Wehrli’s May 20 meeting, Custer met with

the drivers to discuss the status of the

negotiations. The union members voted to reject

NRM’s May 15 proposal, and they authorized the

Union to call a strike. Custer explained that a

strike was premature, because the parties were

still negotiating.

 In the meantime, Wehrli was proceeding

unilaterally with his sales plans. By June 1,

1992, he had found two buyers for the trucks--his

son Robert and a current driver, Richard Downs.

He also placed advertisements in local trade

papers, which yielded the names of ten

prospective outside buyers. By the last week in

June, Wehrli had handshake agreements with five

individuals to sell nine trucks. Between June 28

and 30, he transferred title in those trucks to

the new owners.

 The financial terms that Wehrli set for the

truck sales were favorable for the purchasers,

but in return they gave up almost all control

over the use of the trucks. No down payment was

necessary, and Wehrli supplied the necessary

financing. Each new owner-operator was to be paid

$14 per cubic yard hauled, out of which $1 would

go to pay principal on the debt. Wehrli retained

a security interest in the trucks, under which he

was entitled to find a buyer in default if NRM

had a good faith belief that the driver was

failing to perform the terms of the sales

contract. Most importantly, there was a "first

priority" provision that required the buyers to

give first priority to the hauling needs of NRM

so long as NRM provided reasonable notice of its

intent to use the subcontractor; this requirement

continued until the principal on the truck was

paid off. The sales contract forbade the buyers

from working for NRM’s competitors within a

fifteen mile radius of NRM’s plant. The new

owner-operators were also entitled to purchase

subsidized fuel at the NRM facility and to call

on NRM and WEC mechanics to perform all truck

repairs. Finally, owner-operators were encouraged

to store their vehicles at the NRM facility free

of charge. 

 On July 1, five owner-operator subcontractors

began hauling for NRM under these terms. Except

for the nominal change in ownership of the trucks

and the fact that the new drivers were not part

of the bargaining unit, there were no meaningful

changes in the day-to-day business of hauling at

NRM. The owner-operators all hauled exclusively

for NRM; they received their hauling assignments

from the same individuals and according to

essentially the same procedures as the unit
employee drivers had; they attended the same

monthly safety meetings that NRM had always held;

and they refueled, repaired, and stored their

trucks at the High Grove Street facility.

 Meanwhile, throughout June and July, the

collective bargaining negotiations with the Union

continued. There was at least one meeting in

early June, and on June 15 the parties met with

a federal mediator. The Union modified its offer

at that meeting, as did NRM. Wehrli continued to

insist on a one-year roll-over and the deletion

of Article 24, but he proposed wage and benefit

adjustments modeled after the Union’s recently

ratified contract with NIRMA. Union members

rejected NRM’s offer and two days later they went

on strike. NRM and the Union held brief meetings

June 21 and 22. At the June 22 meeting, Custer

asked Wehrli how the strike might be resolved,

and Wehrli responded that it was too late to

resolve the strike because the trucks had already

been sold. Custer requested information

documenting the sales, but he did not receive it.

Wehrli followed up the June 22 meeting with a

letter to Custer declaring that the parties had

reached impasse on the proposal to sell the

trucks and subcontract NRM’s hauling business.

Custer rejected that claim, and the parties met

again on June 25. The Union offered another

modified contract proposal. NRM rejected it and

instead responded on the same day with a faxed

"Final Contract Proposal." 

 On July 1, non-unit subcontractors began

delivering NRM’s ready mix, and the parties held

another negotiating meeting. The Union made

additional concessions, and Custer told Wehrli

that it would be willing to consider appropriate

modifications of Article 24. At this meeting,

Custer also repeated his request for information

regarding NRM’s sale of its trucks. The next day,

the Union’s counsel sent a letter formally

requesting information regarding terms and

conditions of the sale of the trucks. NRM

responded with a letter stating that it did not

believe that the information was relevant to the

ongoing collective bargaining negotiations and

that the Union had to demonstrate the relevance

of each document it sought access to before NRM

would disclose it. The Union did not respond.

 The parties met again in late July and in early

August. At the August 7 meeting, the Union made

a series of new proposals which NRM rejected.

Finally, on August 18, NRM informed the Union by

letter that it intended to sell all its remaining

trucks and proposed the elimination of an

additional term in the collective bargaining

agreement. In the letter, NRM reminded the Union

that it considered the parties to be "at an
impasse on the issue of [NRM’s] plan to

subcontract all delivery work," but assured the

Union that NRM continued to be willing to

negotiate other aspects of the collective

bargaining agreement.

 The strike that began June 17 continued

throughout this period of negotiation. Wehrli,

who had already encouraged unit workers to take

part in his plan to shift unit hauling work to

subcontractors at the employee meetings in May,

continued to talk to the striking workers about

it on the picket line. Wehrli informed the

strikers that he was selling his trucks and that

if they wanted to continue hauling for NRM they

would have to become owner-operators. He

explained that once the trucks were sold there

would be no more work for them. Wehrli also told

striking workers that they could avoid Union

sanctions for crossing the picket line by signing

documents making them "financial core" members.

NRM subsequently included instructions on how to

become a financial core member and a form for

doing so in paychecks distributed to the

strikers. 

 Despite these efforts, most of the NRM drivers

chose to remain loyal to the Union and continue

the strike. In February of 1993, Custer sent NRM

a letter stating that twenty-four named strikers

wanted to return to work unconditionally. NRM

refused to reinstate them.

 The Union filed a number of charges with the

National Labor Relations Board during the course

of these events. Based on these charges, the

General Counsel ultimately issued a consolidated

complaint against NRM and its affiliated

companies. The complaint began by asserting that

NRM, T&W, and WEC comprised a single employer, as

did NRM and six other corporate entities

(representing the "new" independent trucking

companies that took ownership of some of the

vehicles). Substantively, it claimed that NRM

(meaning for our purposes the whole group)

violated sections 8(a)(5), (3), and (1) of the

Act in several respects: by interfering with the

employees’ union activities through interrogation

and threats (section 8(a)(1)); by direct dealing

with represented employees, unilaterally

transferring bargaining unit work to nonbargaining unit employees, and refusing to

provide information to the Union (sections

8(a)(5) and (1)); and by discharging unit

employees whose work had been reassigned and

refusing to reinstate unfair labor practice

strikers upon their unconditional offer to return

to work (sections 8(a)(3) and (1)).

 The administrative law judge dismissed the
charges in their entirety, but the Board

reversed. 329 NLRB No. 19. It upheld the charges

and ordered the company to cease and desist from

the unfair labor practices it had found, to

restore the delivery work to the unit employees,

and to reinstate both those who lost their jobs

as a result of the unilateral transfer of the

delivery work to the owner-drivers and those who

were not reinstated after the unfair labor

practice strike.

II

 In reviewing the Board’s decision, we give

substantial deference to both its findings of

fact and its interpretations of the Act. Factual

determinations must be upheld if they are

supported by substantial evidence on the record.

29 U.S.C. sec. 160(e). See NLRB v. Roll & Hold

Warehouse & Dist. Corp., 162 F.3d 513, 517 (7th

Cir. 1998); U.S. Marine Corp. v. NLRB, 944 F.2d

1305, 1313-14 (7th Cir. 1991) (en banc). With

respect to questions of law, we defer to the

Board’s interpretation of the statutes it is

charged with administering unless its view is

arbitrary or capricious. See NLRB v. GranCare,

Inc., 170 F.3d 662, 666 (7th Cir. 1999) (en

banc).

 A. Single Employer Status

 NRM first challenges the Board’s conclusion that

NRM, WEC, and T&W are a single employer for

purposes of liability under the Act. We must

decide first whether the legal standard the Board

used to make this determination was a permissible

one. If it is, then the single employer finding

is a factual determination subject only to

substantial evidence review. NLRB v. Emsing’s

Supermarket, Inc., 872 F.2d 1279, 1289 (7th Cir.

1989). NRM’s attack is against both the legal

standard the Board used and its factual

conclusions, but we find no reversible error in

either./1

 The Board acts within its discretion when it

treats as a single employer firms that operate as

an integrated enterprise and "exert[ ]

significant control over" the employees in

question. G. Heileman Brewing Co. v. NLRB, 879

F.2d 1526, 1530 (7th Cir. 1989). In this case,

the Board used its standard four factor test to

determine whether the companies were sufficiently

integrated to constitute a single employer: (1)

common management; (2) centralized control of

labor relations; (3) interrelation of operations;

and, (4) common ownership or financial control.

See Radio and Television Broadcast Technicians

Local Union 1264 v. Broadcast Service of Mobile,
Inc., 380 U.S. 255, 256 (1965). NRM concedes that

this was the proper legal approach in general,

but it argues that the Board erred by failing to

give primacy to the second factor, centralized

control of labor relations. The statute, however,

does not impose such an inflexible weighting

requirement on the Board, nor has the Board

adopted such a rule for itself. At most, the

Board has commented that centralized control of

labor relations is a particularly important

factor, see, e.g., Fedco Freightliners, Inc., 273

NLRB 399 (1984), but it has also consistently

said that this is a contextual inquiry and no one

factor is determinative. Id. at 399; Bistritzky

v. Service Employees Int. Union, Local 32E, AFLCIO, 323 NLRB 524 (1997); NLRB v. Carson Cable

TV, 795 F.2d 879, 881 (9th Cir. 1986). The listed

factors merely help to guide the Board as it

assesses "whether there exists overall control of

the critical matters at the policy level."

Emsing’s Supermarket, Inc., 284 NLRB No. 41 (June

18, 1987), enforced 872 F.2d. 1279 (7th Cir.

1989). 

 On the facts, we find that the Board’s single

employer finding is adequately supported by

substantial evidence. First, as the Board noted,

there is evidence of common ownership. Wehrli and

his wife owned NRM; Wehrli was the sole owner of

WEC; and Wehrli owned 50% of T&W. There is also

substantial evidence of shared management. Wehrli

was an officer in each of the companies; he was

president of NRM and WEC and he was secretary,

and one of only two directors, of T&W. The other

director of T&W, Bob Tilly, was a maintenance

supervisor at NRM and assumed management

responsibilities at WEC on or shortly before July

1, 1992. As the Board pointed out, the only other

individuals involved in the management of these

companies were Wehrli’s wife, his son Scott, and

Jerry Doll. Wehrli also testified before the ALJ

that in the first four months of 1992 it was his

daily practice to "come in and spend time with

each of the managers and officers and whatever

titles they had of the various companies and we

would go over major problems or issues that they

had that they were working on." Finally, there

was evidence of operational integration among the

three companies, including a shared location,

informal sharing of labor among the companies,

and the fact that T&W and WEC served primarily,

if not exclusively, the hauling and maintenance

needs of NRM. Under these circumstances, the

Board was entitled to conclude that the companies

shared common ownership and management. 

 Indeed, the only factor where the record does

not strongly support the Board’s conclusion is

the one NRM has targeted: whether there was

centralized control of labor relations.
Nonetheless, there is significant evidence that

such centralized control existed, and even if it

did not extend to all three companies, the

absence of one factor is not fatal to the Board’s

conclusion. There is no dispute that Wehrli

controlled labor relations for NRM. He was

president of the company and represented it

during negotiations with the Union. With respect

to T&W, Wehrli was one of only two directors and

on at least one occasion it was Wehrli rather

than Tilly who met with the T&W workers to inform

them of the consequences of not continuing to

work during the NRM drivers’ strike. As the Board

concedes, there is little direct evidence that

Wehrli controlled labor relations at WEC, but the

record permits the inference that he did so. He

was president of the company, regularly involved

himself in the management of WEC, and exercised

substantial control over major budgetary

decisions. The record also suggests that it was

Wehrli who directed the use of WEC and NRM

employees in constructing a new ready-mix batch

plant for NRM at the High Grove Street facility. 

 Taken as a whole, substantial evidence indicates

that NRM, WEC, and T&W were highly integrated and

that Wehrli, assisted by a small group of

primarily family members, exercised substantial

control over all aspects of the companies’

affairs. We therefore find that the Board’s

decision to treat them as a single employer is

entitled to enforcement. 

 B. Failure to Bargain

 The Board’s decision in this case rested on one

fundamental finding: that NRM’s sale of its

trucks was part of a plan to shift unit work to

non-bargaining unit subcontractors, and that this

plan was a mandatory subject of bargaining. NRM

has urged all along (successfully to the ALJ)

that it made an entrepreneurial decision to go

out of the trucking business and that it

therefore had no obligation to bargain with the

Union over this plan. The Board rejected this

contention, finding that NRM had not changed the

basic nature of its operations. Instead,

motivated by the desire to reduce labor costs,

"NRM merely replaced the employees driving trucks

with other employees under the ’owner-operator’

rubric (or in some cases the same employees under

the new title), maintaining essentially the same

control over them that it had always enjoyed."

329 NLRB No. 19 at 8. As a result, the Board

concluded, NRM’s plan amounted to subcontracting

unit work, and under section 8(a)(5) of the Act

NRM was required to bargain to impasse prior to

implementing it.
 Before addressing the Board’s decision on the

merits, it is important to explain how the truck

sales should, and should not, be assessed. NRM

has devoted considerable energy in its appellate

briefs to explaining why the sales were not "sham

transactions," as that term is used in alter ego

or single employer cases. See, e.g., NLRB v. Dane

County Dairy, 795 F.2d 1313, 1322 (7th Cir.

1986). But, as we read the Board’s opinion, it

was not invoking that doctrine (despite its

somewhat careless use of the phrase "sham

transaction" here and there). It was not the

Board’s contention that NRM continued to own the

trucks at issue; there is no dispute that title

was legally transferred. The Board was saying

only that the transactions were phony, or "sham,"

insofar as their employment consequences were

concerned. NRM sold the trucks, but it did so as

part of a plan that allowed it to remain in the

business of delivering ready-mix, albeit using

non-union subcontractors instead of bargaining

unit employees. But that was exactly the Board’s

problem: a company cannot, consistent with the

labor laws, shift unit work to subcontractors in

order to save on labor costs without first

bargaining in good faith to impasse. 

 The Board’s conclusion that NRM’s plan to shift

its hauling business away from the bargaining

unit and to subcontractors was a mandatory

subject of bargaining is both based on a

reasonable interpretation of the Act and

supported by substantial evidence in the record.

Section 8(a)(5) of the Act requires an employer

to "bargain collectively with the representatives

of his employees." The Act defines collective

bargaining as "the performance of the mutual

obligation of the employer and the representative

of the employees to . . . confer in good faith

with respect to wages, hours and other terms and

conditions of employment." 29 U.S.C. sec.158(d).

The Board appropriately relied on Fibreboard

Paper Products Corp. v. NLRB, 379 U.S. 203

(1964), to support its conclusion that NRM’s

transfer of its hauling work to non-union

subcontractors was a change in the terms and

conditions of employment over which NRM was

obligated to bargain. In Fibreboard, the Supreme

Court found that a company’s decision to contract

out maintenance work in order to save on labor

costs amounted to "replac[ing] existing employees

with those of an independent contractor to do the

same work under similar conditions of

employment." 379 U.S. at 213. In such a

situation, it held, the employer violates the Act

if it does not first bargain to impasse with the

union. See also First National Maintenance Corp.

v. NLRB, 452 U.S. 666, 679-80 (1981). After

Fibreboard and First National Maintenance, when

an employer chooses to subcontract unit work in
order to save on labor costs, that choice

typically does not involve a change in the scope

and direction of the enterprise and thus is not

a core entrepreneurial decision beyond the scope

of the Act’s bargaining obligation. See Rock-Tenn

Co. v. NLRB, 101 F.3d 1441, 1446 (D.C. Cir. 1997)

(concluding bargaining was mandatory because

shift of unit work to subcontract hauling company

to save on labor costs "is a prototype Fibreboard

case").

 In this case, the Board properly found that

NRM’s sale of its trucks was simply an element of

its plan to switch unit work to lower-cost

subcontractors and that under Fibreboard this

plan could not be implemented until impasse had

been reached. The record amply supports this

characterization. Before and after July 1, 1992,

NRM’s business involved the delivery of ready-mix

concrete to its customers. Neither the scope nor

the manner of this aspect of its business changed

in any way after July 1. To the contrary, Wehrli

ensured that things would stay functionally the

same by carefully structuring the sale of NRM’s

trucks to give NRM nearly complete control over

how the trucks were used. After July 1, the same

trucks were still hauling exclusively NRM’s

product; the drivers still received their orders

from the same dispatcher and in accordance with

essentially the same procedures previously used;

and the trucks were still refueled, repaired, and

stored at the High Grove Street site. The only

identifiable difference in how NRM hauled readymix concrete after July 1 was that the drivers of

the trucks were no longer covered by the Union’s

collective bargaining agreement. 

 There is also substantial evidence in the

record that NRM’s motivation for switching to

subcontract haulers was to save on labor costs.

Wehrli himself admitted that this was what he was

doing, and his statements at the negotiating

meetings leave no doubt about the matter.

Wehrli’s own testimony is sufficient to support

the conclusion that the plan to move to an owneroperator system was motivated by a desire to

reduce labor costs. This is precisely the kind of

concern that Fibreboard and First National

Maintenance instruct is particularly amenable to

resolution through collective bargaining. 379

U.S. at 214; 452 U.S. at 669.

 We agree with the Board that this case is

governed by Fibreboard. At oral argument NRM

argued strenuously that it was entitled to sell

its trucks, but that is not the point. What NRM

was not entitled to do under these circumstances

was to shift unit work to non-union

subcontractors without first bargaining to

impasse with the Union. Of course, had NRM
negotiated to impasse before transferring the

work, there would have been no violation of the

Act. We turn now to the question of whether it

did so, or, if not, whether the Union waived its

right to bargain over the issue. 

 C. Negotiating to Impasse

 An employer violates sections 8(a)(1) and (5)

of the Act when it unilaterally changes a

condition of employment that is a mandatory

subject of bargaining before bargaining has

reached an impasse. NLRB v. Katz, 369 U.S. 736,

743 (1962); Lapham-Hickey Steel Corp., 904 F.2d

1180, 1185 (7th Cir. 1990). Because an employer

is only required to bargain in good faith and may

ultimately refuse to amend its proposals, once

impasse has been reached the employer may

implement its original proposals without

violating the Act. Duffy Tool & Stamping, L.L.C.

v. NLRB, 233 F.3d 995, 996 (7th Cir. 2000). In

the context of ongoing collective bargaining

negotiations, however, we have recently held that

the parties are required to reach an overall

impasse before an employer can unilaterally

implement individual proposals made during the

course of collective bargaining. Id. at 999; see

also Visiting Nurse Services of Western

Massachusetts, Inc. v. NLRB, 177 F.3d 52, 58 (1st

Cir. 1999) (same).

 NRM’s contention that the parties had reached

impasse on the subcontracting issue is precisely

the kind of partial impasse argument foreclosed

by Duffy. Partial impasse does not justify

unilateral implementation of the contested item,

and it is clear both that nothing approaching

total deadlock had occurred between the Union and

NRM at the time NRM unilaterally sold the trucks,

and that NRM’s decision to sell the trucks was

not part of a larger plan to go out of business.

As our earlier review of the course of events

shows, collective bargaining negotiations were

ongoing until at least August 7 or 18, long after

NRM implemented its truck sale plan.

 NRM contends in the alternative that it was not

required to negotiate to impasse because the

Union had waived its right to bargain over the

issue of subcontracting. Duffy recognized that

there could be exceptions to the overall impasse

rule in the event that the employer could

demonstrate that the union waived its right to

bargain over a particular proposal or that the

company would suffer severe economic consequences

from a delay in implementation. 233 F.3d at 997.

 To establish waiver, an employer must prove

that the union’s waiver of its statutorily
protected right was "clearly and unmistakably

articulated." Beverly California Corp. v. NLRB,

227 F.3d 817, 838 (7th Cir. 2000). Alternatively,

a union can relinquish its right to bargain if it

"insists on continually avoiding or delaying

bargaining." Serramonte Oldsmobile, Inc. v. NLRB,

86 F.3d 227, 235 (D.C. Cir. 1996). NRM does not

assert that the Union engaged in any such

dilatory conduct; it must therefore show that the

Union unmistakably waived its right to bargain

over NRM’s proposal to subcontract hauling

services. NRM finds such a waiver in the Union’s

repeated refusal to accept its plan to shift

hauling work to non-union subcontractors and its

proposed modifications of Article 24. The Board

properly rejected this argument. NRM’s waiver

theory is simply a restatement of its singleissue impasse theory using different terminology.

In the context of collective bargaining

negotiations, the Union’s mere refusal to budge

on a particular issue cannot constitute a waiver.

Indeed, the Union expressed its willingness to

discuss changes to Article 24 as late as the July

1 meeting, which further weakens NRM’s argument.

At no time did the Union refuse to negotiate or

fail to negotiate in good faith over the terms of

the successor contract. The record lends ample

support to the Board’s conclusion that while the

Union was opposed to the truck-selling plan, "it

expressed willingness to try to find ways by

which NRM’s economic concerns could be met" and

that "[t]he Union was thus responsive and

persistent rather than dilatory and evasive in

the negotiations." 329 NLRB No. 19 at 9. Under

these circumstances, there was no waiver.

 NRM finally claims that the strike entitled it

to implement its shift to a system of subcontract

haulers, but here it is confusing apples and

oranges. It is true that when workers strike, an

employer may temporarily subcontract unit work in

order "to enable the employer to continue

operating in an emergency situation thrust upon

it by a strike." American Cyanamid Co. v. NLRB,

592 F.2d 356, 360 (7th Cir. 1979). But the mere

fact that employees go on strike does not relieve

the employer of the duty to bargain to impasse,

and thus it does not permit an employer

permanently to subcontract out unit work in the

absence of impasse. Id. All of the evidence

supports the Board’s conclusion that NRM’s

subcontracting was not a temporary response to

circumstances created by the strike, but rather

the implementation of a carefully formulated plan

for a permanent shift of unit work away from

employees and over to subcontractors. 

 D. Failure to Provide Relevant Information
 Section 8(a)(5) of the Act imposes on the

employer a duty to bargain in good faith. This

duty encompasses an obligation on the employer to

disclose information relevant to the bargaining

process. NLRB v. Truitt Mfg. Inc., 351 U.S. 149,

152-53 (1956). Although there are exceptions, in

general an employer violates section 8(a)(5) by

failing to disclose relevant information upon

request. NLRB v. George Koch Sons, Inc., 950 F.2d

1324, 1330-31 (7th Cir. 1991). Whether the

requested information was relevant is the

threshold question and the only one in dispute in

our case. The information the Union wanted was

about NRM’s proposal to subcontract unit work.

The burden was on the Union to demonstrate the

relevance of the requested information under the

very liberal relevancy standard applied in these

situations. See NLRB v. Acme Indus. Co., 385 U.S.

432, 437 n. 6 (1967) (applying a discovery-type

relevancy standard). 

 The Board concluded that NRM violated sections

8(a)(5) and (1) of the Act by failing to give the

Union the requested information about the sale of

its trucks. At the July 1, 1992, negotiating

session, Wehrli indicated to Custer that it was

too late to negotiate a contract with NRM that

covered the NRM drivers, because the trucks they

had been driving had already been sold. Custer

testified that he promptly asked Wehrli to

provide him with documentation of the sales. On

July 10, counsel for the Union sent a letter

again requesting information regarding the nature

and terms of the truck sales. Rather than

providing the requested information, NRM’s

counsel responded with a letter disputing the

Union’s right to have access to the information

and demanding that the Union explain how "each of

the documents requested is reasonably calculated

to elicit information which the Union may need to

properly represent its members and a citation to

case authority which supports the request." The

Union chose not to respond and instead filed an

unfair labor practices charge.

 On these facts, there is again ample evidence

to support the Board’s conclusion that NRM

violated the Act. The Union’s request for

information arose directly out of a subject the

parties were discussing in connection with their

collective bargaining. Under the Court’s

reasoning in Truitt, 352 U.S. at 152-53, the

Union was entitled to know exactly what

circumstances it faced. If NRM’s truck sale claim

was "important enough to present in the give and

take of bargaining," then the Union was entitled

to "some sort of proof of its accuracy." Id. NRM

was aware of the relevance of this information to

the Union’s ability to represent unit members,

and NRM’s subsequent effort to deny its relevancy
is precisely the kind of bad faith negotiating

tactic that is prohibited by section 8(a)(5) of

the Act.

 E. Direct Dealings, Negotiations, and Threats

 Implicit in the obligation to bargain in good

faith "is the principle that the employer is not

to go behind the union’s back and negotiate with

individual workers, nor otherwise to undermine

the union’s status as exclusive bargaining

representative." Szabo v. U.S. Marine Corp., 819

F.2d 714, 718 (7th Cir. 1987); see also Medo

Photo Supply Corp. v. NLRB, 321 U.S. 678, 683-85

(1944). This prohibition forecloses individual

negotiations with unit employees, in most cases

even if collective bargaining negotiations have

reached an impasse. McNealy v. Caterpillar, Inc.,

139 F.3d 1113, 1118 (7th Cir. 1997). Furthermore,

the duty to refrain from undermining the union’s

status as exclusive bargaining agent precludes

promises of benefits or threats of sanctions to

union members that have the effect of reducing

the employees’ support for their union. Beverly

California Corp., 227 F.3d at 817, 832-33. The

Board concluded that NRM repeatedly engaged in

these forms of prohibited activity. 

 We see no need to lengthen this opinion with

yet another rehearsal of the facts. Wehrli’s

meetings with the drivers while negotiations were

still underway and his warnings that those who

did not buy a truck would be laid off support the

Board’s findings. NRM attempts to cast these

meetings as nothing more than occasions during

which Wehrli was providing accurate information

to employees about a "business opportunity." In

the context of the ongoing collective bargaining

negotiations over the very proposal at issue,

however, we find the Board’s characterization

more accurate: "[T]he meetings were efforts to

enlist the employees in the sham transactions by

which [NRM] would carry on the ready mix delivery

operations without the obligations or costs of a

union contract." 329 NLRB No. 19 at 11. These

meetings amounted to direct dealing in violation

of section 8(a)(5) of the Act. 

 With respect to the section 8(a)(1) violation

that the Board found in connection with Wehrli’s

statements that the employees would lose their

jobs if they did not accept the terms of NRM’s

subcontracting plan and that subcontractors would

not be members of the collective bargaining unit,

the record again supports the Board. We find no

merit in NRM’s procedural objection to the effect

that the charges complaining of the alleged

threats made at the meetings and to individual

NRM employees were not timely filed. The threat
charges arose from the General Counsel’s

investigation into precisely the situation about

which the Union had complained in its charge

filed June 9, 1992. The threat charges properly

related back to the June 9, 1992 complaint, and

the Board properly considered them.

 NRM’s argument on the merits that the employees

could not have seen these statements as

"threats," because Wehrli was simply inviting the

employees to negotiate new agreements as owneroperators, is meritless as well. To constitute a

prohibited threat under the Act, a statement must

only "reasonably tend[ ] to interfere with,

restrain, or coerce employees in the free

exercise of their protected rights." NLRB v. Q-1

Motor Express, Inc., 25 F.3d 473, 477 (7th Cir.

1994). The relevant perspective is that of the

employees. Wehrli made it clear to unit workers

at the May meetings and on the picket line that

their only choice was between becoming

subcontract owner-operators outside the current

bargaining unit and losing their jobs. NRM

concedes that this happened. The Board was

entitled to conclude that the employees with whom

Wehrli talked would have felt coerced into

abandoning the Union in the midst of the Union’s

ongoing collective bargaining negotiations with

NRM. The Board’s conclusion that NRM violated

section 8(a)(1) is well within the bounds that

this record would support.

 F. Wrongful Discharge and Failure to Reinstate

 The Board found that NRM violated sections

8(a)(5) and 8(a)(3) of the Act by transferring

unit work to non-unit personnel in order to

eliminate the Union as the unit bargaining

representative. The Board also found that NRM

violated section 8(a)(3) of the Act by failing to

reinstate employees who made an unconditional

offer to return. Again, we find the Board’s

conclusions to be supported by substantial

evidence in the record. The charges were

sufficiently related to the initial complaints to

be properly before the Board, and our approval of

the Board’s section 8(a)(5) analysis with respect

to the transfer of unit work to non-unit

subcontractors is equally applicable here.

 Section 8(a)(3) of the Act prohibits

"discrimination in regard to hire or tenure of

employment or any term or condition of employment

to encourage or discourage membership in any

labor organization." The Board reasoned that NRM

violated section 8(a)(3) when it forced union

employees to choose between abandoning their

union to become owner-operator subcontractors and
having no job at all. In effect, the Board viewed

NRM’s statements as a promise that there would

only be work for those who renounced their union

membership. The Board properly concluded that

imposing this impermissible choice upon the unit

workers was a violation of the Act. See Canteen

Corp. v. NLRB, 103 F.3d 1355, 1365-66 (7th Cir.

1997). In this case, those NRM drivers who

refused to abandon the Union in order to

participate in NRM’s unilaterally implemented

switch to subcontract hauling were constructively

discharged as NRM sold its trucks and replaced

bargaining unit workers with owner-operator

subcontractors. The fact that the unit employees

were on strike at the time is of no consequence.

We thus affirm the Board’s conclusion that NRM

violated section 8(a)(3) of the Act by offering

only those who would abandon the bargaining unit

continued employment.

 Finally, the Board found that NRM violated

section 8(a)(3) of the Act by refusing to

reinstate striking workers who made an

unconditional offer to return to work. It is

settled that "unfair labor practice strikers are

entitled to reinstatement upon making an

unconditional offer to return to work."

Lapham-Hickey Steel Corp., 904 F.2d at 1188;

accord Richmond Recording Corp. v. NLRB, 836 F.2d

289, 292 (7th Cir. 1987). The Board found, and we

agree, that this was an unfair labor practices

strike,/2 and there is substantial evidence in

the record to support the Board’s conclusion that

an unconditional offer was made and that NRM did

not reinstate the workers. Given the absence of

any contrary evidence in the record, this

evidence is sufficient to support the Board’s

finding that NRM failed to reinstate the striking

workers in violation of the Act.

III

 Last, NRM argues that the Board’s order

requiring restoration of NRM’s trucking

operations and reinstatement of employee truck

drivers should not be enforced because it is

unreasonable and imposes an "undue or unfair

burden." NRM concedes, however, that it did not

make this argument before the Board. The Act very

clearly states that an objection "not urged

before the Board . . . shall [not] be considered

by the court, unless the failure or neglect to

urge such objections shall be excused because of

extraordinary circumstances." 29 U.S.C.

sec.160(e). NRM does not point to any

extraordinary circumstances justifying its

failure to urge this objection before the Board

and thus our hands are tied. Relying on our

opinion in NLRB v. Thill, Inc., 980 F.2d 1137

(7th Cir. 1992), NRM suggests that because
enforcement of the Board’s order is an equitable

remedy we should use our equitable powers to

decline to enforce the injunction. Even if this

were an avenue open to us (which we doubt, given

our duty to defer to the Board), we would decline

to take it in this case, notwithstanding the

Board’s unfortunate delay in issuing its opinion.

First, this is a point NRM saved for its reply

brief, and it is therefore not properly before

us. Second, as the Supreme Court held in NLRB v.

Ironworkers, 466 U.S. 720, 725-26 (1984), courts

do not have discretion to impose the costs of

delay by the Board upon the wronged employees.

Finally, the overall equities in this case do not

favor NRM. It committed numerous violations of

the National Labor Relations Act, and those

violations led to the improper dismissal of

bargaining unit employees. In contrast, there is

no evidence of any wrongdoing on the part of the

Union or the striking workers. To refuse to

enforce the Board’s order because of time delays

that no one alleges are attributable to the Union

or the unit workers would unjustifiably compound

their injury.

 In addition, we are not persuaded that

compliance with the Board’s order will impose an

unusual hardship on the employer. NRM contends

that the order is unreasonable because it would

be forced to buy back all its trucks from the

owner-operators and revert to a system of hauling

that it has not used in almost eight years. The

order, however, says nothing about where NRM

should procure its trucks, or whether it should

buy or lease them. NRM merely needs to make

trucks available so that the reinstated

bargaining unit employees can return to hauling

ready-mix. Furthermore, there is no evidence that

NRM will have any particular difficulty returning

its hauling business to unit employees; NRM

apparently continues to deliver ready-mix to its

customers just as it did eight years ago. NRM has

given us no reason to think that the transition

from subcontract hauling to in-house hauling

would be any more difficult than the 1992 switch

to using subcontractors. For all these reasons,

we conclude that the Board’s order is entitled to

be Enforced in its entirety.

FOOTNOTES

/1 Neither party has raised the question whether

this decision is exclusively one to be made under

federal law, or if state law bears on it as well.

We therefore proceed, as the parties did, as if

it is governed by federal law.

/2 NRM has not tried to justify its refusal to

rehire on the ground that it had hired

replacement workers for economic strikers, and
thus was entitled to turn away returning workers

who wanted jobs that had been filled. This is

understandable, as NRM’s entire point has been

that the hauling subset of its business had been

eliminated.