The Supreme Court yesterday agreed to decide whether a union violates the law when it threatens to discipline or actually punishes a member who crosses a picket line to do certain work during a strike.

The court will hear 1 1/2 hours of argument in its 1977-1978 term in three related West Coast cases growing out of a four-month strike in 1973.

The strikers were supervisors who were members of the Writers Guild of America, West, Inc. The employers were the three major television networks and various independent film production companies.

The issue centers on Guild members known as "hyphenates" - union members who work mainly in non-writing supervisory roles, such as story editors, directors, producers or production executives. They represent employers in in-house grievance-adjustment cases and in collective bargaining.

Before and after the strike began in March 1973, Guild officials threatened to fine and/or blacklist hyphenates who would or did cross picket lines to work in any capacity.

The employers, meanwhile, insisted that the hyphenates cross the lines to do what they and the National Labor Relations Board termed normal duties and excluded work normally done by rank-and-file writers.

The Writers Guild contended, however, that the supervisor members performed what the union contract defined as "writing services." In addition, the union said, the hyphenates had "no collective bargaining functions, and little if any grievance adjustment functions as to other members of the Guild."

Finally, the Guild charged 31 hyphenates with having crossed picket lines, but union trial committees convicted only 10 of them in disciplinary proceedings. The 10 were expelled or suspended and fined.

The employers - including ABC, CBS and NBC - filed unfair labor practice charges, against the Guild. The NLRB ruled 2 to 1 for the employers, holding that union discipline of supervisors for crossing picket lines violates the National Labor Relations Act by tending to deprive employers of the hyphenates' supervisory services.

But a divided Second U.S. Circuit Court of Appeals agreed with NLRB dissenter John H. Fanning that previous court decisions had upheld such disciplining.

Emergency Petroleum Allocation Act

The Emergency Petroleum Allocation Act of 1973 directed the Federal Energy Administration to regulate the prices at which refiners sell petroleum products covered by the law.

To implement the law, the FEA issued a regulation controlling the credit terms and payments schedules to be used by suppliers in selling regulated petroleum products.

In a suit supported by virtually all domestic refiners, Marathon Oil Co. complained that the FEA regulation was an improper curtailment of the ability of all sellers of crude one and refined petroleum products to adopt "rational and economically sensible credit policies in response to current credit market conditions."

The U.S. Temporary Emergency Court of Appeals disagreed, saying in a ruling last December that regulation of credit terms and other business practices are "tied closely" to the regulation of prices directed by Congress.

Yesterday, the Supreme Court let the ruling stand.