– Companies won two unanimous U.S. Supreme Court rulings, averting what they said might have been billions of ­dollars in new liability.

The court on Monday gave airlines greater immunity from lawsuits when they report potential security threats, throwing out a jury verdict won by an Air Wisconsin pilot. The justices also ruled for U.S. Steel Corp. by saying companies in many cases don’t have to pay workers for time spent putting on and taking off safety gear.

In the airline case, the court said companies can’t be sued when they report threats to the Transportation Security Administration (TSA) as long as the information the carriers provide is “materially true.”

“Congress wanted to ensure that air carriers and their employees would not hesitate to provide the TSA with the information it needed,” Justice Sonia Sotomayor wrote. The decision overturned a lower-court ruling that ­airlines said would have left them legally vulnerable.

The justices threw out a $1.4 million award won by the pilot, William L. Hoeper. He sued the airline for telling ­federal officials as he was preparing to board a flight that he was “unstable” and possibly armed.

Three of the nine justices — Antonin Scalia, Clarence Thomas and Elena Kagan — dissented from that part of the ruling. They said the high court should have let the lower courts decide whether the ­airline’s report met the “materially true” standard.

Air Wisconsin Airlines Corp. flies for US Airways Group Inc., which joined with AMR Corp. in December to create American Airlines Group Inc. The case tested the 2001 Aviation and Transportation Security Act, a law enacted two months after the Sept. 11 terrorist attacks.

Vaughn Jennings, a spokesman for the trade group Airlines for America, said the court “recognized the importance of immunizing prompt reports by airlines of suspicious activity and potential security threats.”

Eden Prairie attorney Donald Chance Mark Jr. was on the legal team representing Air Wisconsin.

U.S. Steel case

In the wage case, the justices said the U.S. Steel employees are bound by their collective bargaining agreement, which says they get paid only for time at their work stations. The workers argued that wage-and-hour laws entitled them to additional wages no matter what the union agreement said.

Corporate trade groups said a ruling in the workers’ favor would have been costly.

The Grocery Manufacturers Association said a defeat would have forced companies to pay millions of employees more than $1,500 each.