A Federal law stopping employer landed groups from financing law-suits by union members against their unions is unconstitutional, U.S. District Court Judge Charles R. Richey ruled yesterday.

The provision blocking such activity is unconstitutional because it violates the First Amendment rights of the groups and the persons who contribute to those groups, Richey said.

Richey's ruling came in a 4-year-old, bitterly fought suit brought by 10 unions against the National Right to Work Legal Defense and Education Foundation, which has financially supported numerous lawsuits against unions in the past by members of those unions.

Much of the legal controversy over the past two years has involved the refusal of the right-to-work group to turn over a list of its contributors to the unions as it had been ordered to do by Judge Richey.

Richey ruled, however, that the refusal of the group to turn over its membership lists amounted to a tacit admission that the claims it was an employer-funded organization were true.

The unions said that, if the right-to-work group was funded by employers, it was violating a federal law that prohibited such groups from financing lawsuits by individual workers against unions to which they belong.

The right-to-work group has been involved in the past in suits by individual union members challenging the union's use of dues money for political activities, challenging the tax-exempt status of unions, and challenging the validity of the "agency-shop" concept, for example.

Union officials said the group's suites amounted to harassment, and union lawyers said the suit in Richey's courtroom was an attempt to point out that the actual purpose of the right-to-work group was to weaken the strength of labor unions.

The right-to-work group countered, however, that the law banning such activity violated the First Amendment rights of petition, association and speech of the foundation and its contributors.

Richey agreed that the ban "clearly, directly nd absolutely" interfered with those First Amendment rights in ruling in favor of the right-to-work group.

He rejected the union's contention that the ban was necessary because it served a "compelling state interest" in labor-management relations, saying the ban was written too broadly to serve such a purpose.

"If Congress wants to effectuate the governmental interests in the regulation of labor-management relations which are purportedly servedf by the proviso, then it must achieve its goal by means that have a less drastic impact on the continued vitality of First Amendment rights," Richey said.