A suit challenging constitutionality of Montgomery city and Alabama state segregation laws will be heard by three-judge panel in federal court here Friday.

The complaint, bearing the names of six Negroes and filed as an outgrowth of the mass boycott now in its sixth month, seeks a declaratory judgment holding the anti-race mixing laws invalid, and an injunction to stop the city and state from enforcing them.

Montgomery City Lines, Inc., a privately owned carrier which operates the city's only bus service, has already abandoned segregation for its part. Its drivers have been ordered to refrain from separating white and Negro passengers.

But there have been no reports of actual integration because most Negroes are still boycotting the bus line in protest against threats of arrest from pro-segregation city commissioners. Negroes who have continued to patronize the buses have kept to the rear seats where they always sat.

The City of Montgomery has asked Circuit Judge Walter B. Jones in circuit court for an injunction to compel the bus company to rescind the integration order. Jones may announce his ruling this week.

City attorneys contended at a hearing last Thursday that the continued existence of the non-segregation policy has created serious tension in Montgomery. Police Commissioner Clyde Sellers testified that in his opinion a breakdown of segregation would invite rioting and would make it "dangerous for people to walk the streets."

If the three-judge federal panel sitting here Friday takes jurisdiction and rules on the legality of the segregation laws as requested, the outcome either way is certain to be appealed direct to the Supreme Court.

City and state attorneys have questioned the panel's jurisdiction, arguing that the Attorney General's office, although made a defendant, doesn't exercise jurisdiction over city buses in Montgomery.

A three-judge panel is chosen to test constitutionality of state laws when state officials enforce them.

The Negroes contend the panel does have jurisdiction and are asking for an injunction to prevent either the city or state from enforcing bus segregation laws in Montgomery.

If the panel's decision goes direct to the Supreme Court, it probably will get there ahead of the case from South Carolina on which the high court acted April 23, since that case must be tried again on a question of damages.

The ruling two weeks ago was first interpreted as a decision outlawing bus segregation. But some attorneys have contended since then that the Supreme Court dismissed an appeal only because the case was still pending in the lower court.

It began as a claim for damages by a Negro woman forced to give up her seat on a bus in Columbia, S.C. A judge in U.S. District Court dismissed it; the fourth U.S. Circuit Court of Appeals reversed him, holding the segregation laws invalid, and sent the case back for trial.

The South Carolina Electric & Gas Co. appealed to the Supreme Court and the appeal was dismissed.

Lawyers are divided over the effect of the Supreme Court's order. Attorneys for Montgomery City Lines argued last Thursday that the decision merely sent the South Carolina case back for trial and wasn't a ruling on segregation itself.

There is no issue of damages in the case pending here. If the panel rules Alabama city and state segregation laws unconstitutional, for example, the next step would be an appeal in the Supreme Court for the decision here to be upheld or reversed.

`The South Carolina case hasn't been set for trial in district court, so the issue here may reach the Supreme Court first.