Utah Sens. Mike Lee and Orrin Hatch and Delta Air Lines officials say the Persian Gulf country of Qatar is up to some old tricks that hurt U.S. carriers.

That comes a year after Utah politicians from Gov. Gary Herbert to Salt Lake City Mayor Jackie Biskupski protested that Qatar’s subsidies of its national airline had forced Delta and others to drop service on some routes to the Middle East and India — a move they said hurt Delta’s Salt Lake City hub and employees.

Lee and Hatch, both R-Utah, are among 13 senators who say Qatar Airways bought a 49 percent share of struggling Air Italy, and again is trying to use subsidies from the Qatari government to lower its fares and eliminate competition on some lucrative European routes.

They wrote to Transportation Secretary Elaine Chao, Commerce Secretary Wilbur Ross and Secretary of State Mike Pompeo asking them to investigate whether Qatar is breaking international agreements.

“Qatar Airways’ recent acquisition of Air Italy raises a healthy skepticism that Qatar is complying with all obligations under our Open Skies agreement,” Lee wrote.

FILE - In this Feb. 22, 2018, file photo, Sen. Mike Lee, R-Utah, speaks on the Senate Floor at the Utah state Capitol in Salt Lake City. President Donald Trump's list of candidates for the Supreme Court, posted on White House website in November 2017 includes Lee. (AP Photo/Rick Bowmer, File)

“Efforts by foreign governments to either subsidize or provide other benefits to their air carriers can create severe market distortions and cause harm to American carriers and consumers,” he said.

Delta Air Lines CEO Ed Bastian also wrote a commentary for the news media similarly calling for an investigation.

He said that after Air Italy posted a loss of 18.2 percent last year, it suddenly — with money from its new partner of Qatar Airways — “announced a major global expansion of flights between Milan and North American cities including New York, Chicago, Los Angeles, San Francisco and Toronto.”

Bastian said that comes after a recent agreement by Qatar to “finally take steps toward fair competition in aviation ... . Only months later, Qatar is back to [its] old tricks, thumbing its nose at the Trump administration with its clumsy scheme to get around its promises.”

Francisco Kjolseth | The Salt Lake Tribune New Delta Airlines CEO Ed Bastian about future of Delta and its operations in Salt Lake City during an interview on Tuesday, Sept. 13, 2016.

Bastian added, “These Italian routes, already highly competitive and well-served by existing carriers, are simply not economically viable without Qatari subsidies. By flooding these markets with subsidized capacity and dropping prices far below costs, Qatar is launching another assault on U.S. airline employees and travelers.”

Hatch joined a letter signed by 11 senators — led by Sen. Ted Cruz, R-Texas — complaining, “Air Italy’s entry into this crowded market appears consistent with Qatar Airway’s pattern of adding subsidized capacity in markets where demand is already well-served.”