THE COMMUNICATIONS WORKers of America (CWA) used to have a simple answer for employees of small companies who asked to join: Forget it.

Such workplaces, the union believed, weren't worth the expense of servicing. These days, though, "whether it's big or small gas nothing to do with whether it's worth pursuing," says Larry Cohen, a regional organizing director.

CWA isn't the only union that's changing its strategy. With union membership steadily declining, many organizers are targeting an untapped market: small companies. "The unions used to organize the large companies, because that's where the jobs were," says Thomas Kochan, who teaches industrial relations at Massachusetts Institute of Technology. "But they are now seeing their role as meeting the needs of the labor force as they find it." That means broadening their appeal beyond crumbling heavy industries and into small service and technology businesses, such as nursing homes and financial services.

The unions have no time to waste. Only about 15% of civilian workers are unionized, compared with more than 26% during the movement's heyday in 1953. Smaller shops may provide one bright spot. "Unions lose most representation elections, but their win rates are better at smaller units," says Audrey Freedman, a labor economist at The Conference Board. Adds Karen Nussbaum, of the Service Employees International Union: "Organizing a union means people have chosen to work together as a group. You find more successes in smaller places, because everybody knows each other."

Winning elections is the easiest part. Unions haven't learned how to serve small workplaces efficiently in such areas as arbitration and grievance proceedings. AFL-CIO organizers, for instance, may focus on geographical clusters of these companies. "You've got to organize a whole bunch to make it cost-effective," says Charles McDonald, assistant organizing director.

Unions may be less interested in enlisting small businesses than in boosting their self-image with a few victories. "There's more bark than bite," says Leo Troy, a labor economics professor at Rutgers University. "When you consider the magnitude of the unions' losses, organizing small workplaces is a joke."