United Airlines is canceling basic cooperation agreements with five Middle East airlines, including Qatar Airways and Emirates Airline, as the Chicago-based carrier continues to complain that the largest airlines in the region compete unfairly by taking massive government subsidies.

United will no longer maintain interline agreements beginning May 5 with Fly Dubai, Royal Jordanian Airlines, Saudi Arabian Airlines, Emirates and Qatar Airways, it told employees.

Customers will not be able to buy tickets with one segment on United, and another on one of the Middle East carriers. Occasionally, with hard-to-reach destinations, agents will issue tickets with one segment on United, and another on a United competitor.

United also won’t be able to book passengers on the other airlines during irregular operations. This might be an issue if a customer is flying from San Francisco to Frankfurt on United, then to Dubai on Lufthansa. If the San Francisco-Frankfurt leg cancels, United cannot put the customer on a nonstop Emirates flight. And customers who buy separate tickets — perhaps one on United and one on Qatar — will not be able to ask United to check bags to the final destination.

United maintains interline agreements with more than 150 airlines, and some, including American Airlines, Delta Air Lines and British Airways, are also fierce competitors. Many other airlines covered by agreements are so obscure they’re likely rarely used, like deals with Russia’s Yakutia Airlines, and MIAT Mongolian Airlines.

United’s decision — at least with Emirates and Qatar — is not a major surprise. In recent months, United CEO Oscar Munoz has sharply criticized Emirates, Etihad and Qatar for taking almost $50 billion in government subsidies since 2004. He has said the carriers are more branding tools for their governments than for-profit carriers. “Those airlines aren’t airlines,” Munoz said on March 2.

The back-and-forth continued this month, after United employees in Chicago called security officers to remove a passenger from a plane because the airline needed his seat for a crew member. When Qatar updated its mobile app later that week, it included a note that said it “Doesn’t support drag and drop.”

And Emirates created an advertisement after the incident, mentioning Munoz’s March comments and chiding United for its response to the Chicago incident.

“Well, Mr. Munoz, according to TripAdvisor, the world’s largest travel site, not only are we a real airline, we are the best airline,” the ad said. It ended with a message saying, “Fly the Friendly Skies. This time for real.”

United announced a settlement yesterday for an undisclosed amount with the doctor who was dragged off the flight in Chicago.

United has not engaged in similar public criticism of Fly Dubai, Royal Jordanian or Saudi Arabian Airlines. Those carriers are less of a competitive threat to U.S. airlines.

In an email, a United spokesman confirmed the agreements will end but did not say why. “As part of the continuous monitoring and adjustment of our partnership agreements, United has decided to end its interline agreements with some airlines in the Middle East, effective May 5, 2017,” the spokesman said.

United is not the first U.S. airline to reduce its interline agreements with some Middle East Airlines. In 2015, Delta canceled its agreement with Emirates.

An Emirates spokeswoman said the airline retains interline agreements with four North American airlines — Porter Airlines, Virgin America, Hawaiian Airlines and Sun Country Airlines. It also has closer codeshare relationships with Alaska Airlines, JetBlue Airways, and WestJet Airlines.

Photo Credit: After United's embarrassing April 9 incident in Chicago, Emirates created an ad mocking United. Now, United has canceled its interline agreement with Emirates and four other carriers. Emirates