The Supreme Court gave unions on Tuesday important new protection against being sued by rank-and-file members who say they have received unfair or inadequate representation.

The justices unanimously threw out a lawsuit against the Air Line Pilots Association stemming from a disputed settlement of a Continental Airlines pilots strike.In other decisions, the high court:

-Let railroads ignore their union contracts when completing mergers approved by federal regulators. The court, by a 7-2 vote, said Congress had intended to protect against union interference with rail mergers when it passed the Transportation Act of 1920.

-Ruled 6-3, that a federal law allowing the winners in some lawsuits to have their legal fees paid by the losers does not cover expert-witness fees.

Writing for the court in the airline pilots' case, Justice John Paul Stevens said there is a "wide range of reasonableness within which unions may act without breaching their fair representation duty."

Even a bad strike settlement is not necessarily unfair to union members, he said.

The ruling is a victory for the Bush administration, which joined the pilots association in urging the court to limit judges' power to second-guess labor settlements.

The case stemmed from a strike against financially troubled Continental that began in October 1983 and ended two years later. In the interim, more than 1,600 pilots either stayed on the job or were hired to replace the strikers - who numbered about 1,000.