The United States Supreme Court had held that although an employer who terminated a contract with one of its commercial customers purely for economic reasons was required to bargain with the union about the effects of its decision, there was no duty to bargain with the union about the decision itself.
First National Maintenance Corp. v. National Labor Relations Board, 452 U.S. 666 (1981)
Carol A. Behers,
Labor Law - National Labor Relations Act - Duty to Bargain Over Partial Closings,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol20/iss3/7