United Airlines says Jeff Smisek steps down as CEO effective immediately, names Munoz CEO

United Airlines says Jeff Smisek has stepped down as CEO, chairman and president effective immediately and has named Oscar Munoz as president and chief executive officer.

Munoz will continue to serve on the board.

The Chicago company also said Tuesday its executive vice president of communications and government affairs and its senior vice president of corporate and government affairs have both stepped down.

United says the departures are connected with the company's probe related to a federal investigation associated with the Port Authority of New York and New Jersey. The investigations are ongoing and the company continues to cooperate with the government.