Ps, eight female employees, filed this action against their D for relief under Title VII and under the Equal Pay Act. Ps claim that D had established a discriminatory employment job classification structure under which female employees were paid less in some classifications than male employees in another classification, though the requirements of skill, qualifications, responsibilities, and efforts were comparable in both classifications. Ps sought injunctive relief and 'back pay' under their Title VII count and 'liquidated damages under the Equal Pay Act' count. D sought by motion to add the International Chemical Workers' Union and Local No. 45 of the Union (Unions) as parties defendant and for leave to file a third-party complaint against the Unions, seeking contribution from them for any award against it in this Title VII and Equal Pay Act suit. The basis for such third-party complaint for contribution was the provision of the collective bargaining agreement requiring observance by the parties of 'the principles of equal pay for women as for men when doing the same quantity and quality of work or the same job. . . .' D alleged in its proposed cross-complaint that the Unions were 'legally required to contribute their proportionate share of liability should Ps recover against D. Ps and the Unions moved to dismiss D's motion to add the Unions as parties defendant and D's petition to file the proposed cross-complaint. The district court granted with qualifications the motion to add the Unions as parties defendant and dismissed D's proposed cross-complaint. The court granted D's motion to add the Unions for the limited purpose of fashioning any necessary equitable relief related to the collective bargaining agreement. The district court dismissed the motion to add the Unions as parties defendant. Addressing the petition of PPG to file a cross-complaint for contribution, the district court found that It held that D's proposed cross-complaint was contrary to Northwest Airlines, Inc. that held that a defendant in either a Title VII or an Equal Pay Act suit had no right of contribution. D appealed.