The Supreme Court had been asked to review a decision that an employer can't use a charge of sex disrimination in a union to oppose certification of the union as a collective-bargaining representative.

The decision was the first by a federal appeals court to examine a 1977 National Labor Relations Board ruling that charges of discrimination must be adjudicated not inthe period when a union is seeking certification as a bargaining agent, but in unfair labor-practice proceedings in the NLRB, and proceedings before the Equal Employment Opportunity Commission, or in private litigation.

The case dates back to 1973, when a 4,300-member Chicago-are local of the International Union of Operating Engineers, AFL-CIO, petitioned the board for a representation election among the handful of stationary engineers at a Bell & Howell company plant in Lincolnwood, Ill.

Local 399 won the election, 7-to-1, in February 1974. The company then tried to disqualify the local as the enfineers' representative on the ground that it practiced sex discrimination. At the time, according to evidence offered by the company, the local had no women officers, business agenst, or members.

That effort failing, Bell & Howell refused to bargain with the local. The union responded by filing charges of unfair labor practices with the board.

But the NLRB, relying on the 1977 ruling in what is known as the Handy Andy case, ruled for the union and ordered the company to bargain with it. The proper form for sex-discrimination charges is a proceeding on alleged unfair labor practices, the board said.

Last January, the 7th U.S. Circuit Court of Appeals upheld the board. The National Labor Relations Act doesn't require the board "to consider allegations of discrimination prior to certifying a victorious union, at least where the proffered evidence of dicrimination relates to past union misconduct outside the bargaining unit that the union seeks to represent," the court said.

"Permitting an employer to inject allegations of discriminatoin into a prepresentation proceeding would tend to undermine" the protections of the labor laws, the court said.