The chair of the Federal Communications Commission is opening a probe into NBC-parent Comcast’s relationships with its local broadcast TV affiliates, the latest in a series of investigations into major U.

The letter, dated Tuesday and released publicly Wednesday, was addressed to Comcast CEO Brian Roberts. In it, Carr, who was appointed by President Donald Trump, said he had directed the FCC’s Media Bureau to conduct the inquiry to “ensure compliance with FCC regulations as well as the public interest standard.”