A petition has been filed with the Federal Communications Commission to deny the renewal of broadcasting licenses for three Baltimore television stations owned by Sinclair Broadcasting, citing the lack of diversity of viewpoints, The Baltimore Sun reports.

Baltimore has eight broadcast commercial television stations, not including PBS affiliates.  Sinclair controls three of them, or 38% of the broadcasters.

The petition filed by Columbia, Maryland resident Ihor Gawdiak notes that “Sinclair controls three television stations in Baltimore, while the FCC rules do not permit it to control more than one.”

This petition challenge is the latest headache for Baltimore County-based Sinclair Broadcasting.  The owner of 193 television stations in the US, Sinclair faced an internal backlash from local news teams when it mandated local stations carry highly-partisan segments, including “opinion” segments by ardent Trump supporter and republican operative Boris Epshteyn.  Epshteyn has since been fired from the company.

Sinclair was forced to admit that some of its content was unlabeled “paid content”–known in the industry as “native advertising”–which matches the look and feel of local news pieces.

It also lost its 2017 attempt to purchase Tribune Media when it was discovered that Sinclair inflated advertising revenues in FCC filings; it’s facing a nearly $50 million fine for filing false information with the FCC.