NEW YORK — (CNN) United Continental’s CEO and two other top executives are out following a company investigation related to an ongoing federal probe.

Jeff Smisek, the company’s CEO and chairman, have stepped down, the company said Tuesday.

“The departures announced today are in connection with the company’s previously disclosed internal investigation related to the federal investigation associated with the Port Authority of New York and New Jersey,” the company said in a statement. “The investigations are ongoing and the company continues to cooperate with the government.”

United disclosed in February that a federal grand jury had subpoenaed information from its executive officers. The subpoenas requested records and testimony related to individuals formerly associated with the Port Authority.

Media reports at the time said federal investigators suspected United of adding direct flights to South Carolina near the home of Port Authority official David Samson.

United named Oscar Munoz, who headed the transportation company CSX Corporation, as its new president and CEO.

The-CNN-Wire ™ & © 2015 Cable News Network, Inc., a Time Warner Company. All rights reserved. (Photo: CNN)