## Facts

- South Prairie Construction Co. and Peter Kiewit Sons’ Co. were highway contractors and wholly owned subsidiaries of the same parent corporation.
- A union was the recognized bargaining representative for a unit of Kiewit employees covered by a collective-bargaining agreement.
- The union filed an unfair labor practice charge alleging the companies were a single employer and that South Prairie unlawfully refused to apply the Kiewit agreement and recognize the union for South Prairie employees under NLRA §§ 8(a)(1) and 8(a)(5).
- An ALJ found the companies were a single employer based on factors including centralized control of labor relations and interrelated operations.
- The NLRB reversed, found the companies were separate employers, and dismissed the complaint without making a detailed § 9 bargaining-unit determination.
- The D.C. Circuit reversed the Board’s separate-employer finding, held the companies were a single employer, treated the combined employees as the appropriate bargaining unit, and remanded for enforcement of an order consistent with that view.

## Issues

1. Whether the court of appeals properly rejected the NLRB’s finding that the companies were separate employers and concluded they were a single employer under the NLRA.
2. Whether the court of appeals exceeded its role by deciding, in the first instance, the § 9 appropriate bargaining unit and effectively determining an unfair labor practice, rather than remanding those matters to the NLRB.

## Decision

- The Supreme Court affirmed the D.C. Circuit’s judgment insofar as it set aside the NLRB’s separate-employer finding.
- The Supreme Court vacated the D.C. Circuit’s judgment insofar as it made an initial § 9 bargaining-unit determination and proceeded to impose an unfair labor practice conclusion on that basis.
- The case was remanded with instructions that the bargaining-unit question and related matters be returned to the NLRB for initial determination.

## Legal Principles

- Selection of an appropriate bargaining unit under NLRA § 9 lies largely within the NLRB’s discretion, and reviewing courts rarely disturb the Board’s unit determinations.
- A court of appeals may correct NLRB error on a single-employer finding when the Board’s conclusion is not warranted by the record.
- Even after correcting a Board error on single-employer status, a reviewing court must remand for the NLRB to make the initial § 9 unit determination and any related unfair labor practice analysis; a court that decides the unit question first improperly intrudes into the Board’s assigned function.
- Single-employer status does not itself dictate what bargaining unit is appropriate; the unit determination remains a distinct inquiry committed initially to the NLRB.

## Conclusion

The Supreme Court held that, while a reviewing court may overturn the NLRB’s single-employer analysis when unsupported by the record, it may not decide the § 9 appropriate bargaining unit in the first instance; that determination must be made initially by the NLRB on remand.


South Prairie Constr. Co. v. Loc. No. 627, Int'l Union of Operating Eng'rs, 425 U.S. 800 (1976)