JetBlue Airways Corp has been sued for allegedly blocking online travel agencies from displaying its fares alongside other carriers’ fares, in an illegal bid to steer travelers to its website and charge more.

Fareportal Holdings Inc, which operates the CheapOair and OneTravel websites, is seeking unspecified damages in its antitrust lawsuit filed on Tuesday night in the federal court in Brooklyn.

It said JetBlue’s refusal to let it display the carrier’s fares was meant to thwart comparison shopping and enable JetBlue to boost fares along its strongest routes, including to and from New York, Los Angeles, Boston, Florida and Puerto Rico.

Fareportal said JetBlue’s more than $1.8 billion of taxpayer support and U.S. Treasury loans to weather the COVID-19 pandemic has cushioned the Long Island City, New York-based carrier’s ability in the near term to lose travelers who book elsewhere.

“JetBlue is using COVID-relief handouts from American taxpayers to take American consumers for a ride,” and “make it difficult if not impossible for travelers to determine the airline that offers the best combination of price and service,” the complaint said.

The carrier did not immediately respond on Wednesday to a request for comment.

Southwest Airlines Inc is alone among major U.S. carriers in traditionally shunning third-party booking sites.

Fareportal said JetBlue ended their nearly 20-year relationship after unexpectedly abandoning talks on a multi-year extension.

It said JetBlue still lets Expedia and Priceline, a unit of Booking Holdings Inc, show its fares but intends “in the near future” to stop.

“We have healthy relationships with hundreds of other carriers,” Fareportal’s chief legal officer Fred Stein said in an interview. “A business relationship is all we’re looking for.”

More than 520,000 JetBlue tickets worth $170 million were sold through Fareportal in 2019, the complaint said.

JetBlue stopped working with 12 smaller booking sites in Oct. 2017.

The carrier on Nov. 30 projected a 70% decline in fourth-quarter revenue.

The case is Fareportal Holdings Inc et al v JetBlue Airways Corp, U.S. District Court, Eastern District of New York, No. 21-00061. (Additional reporting by Tracy Rucinski in Chicago.)