The Federal Communications Commission is planning to fine Sinclair Broadcasting Corp. $13.3 million after the company failed to properly disclose that paid programming running on local TV stations was sponsored by a cancer institute, Reuters reports, citing three sources who have been briefed on the situation.

“The proposed fine, which covers about 1,700 spots including commercials that looked like news stories that aired during newscasts for the Utah-based Huntsman Cancer Institute over a six-month period in 2016, could bolster critics of Sinclair’s proposed $3.9 billion acquisition of Tribune Media Co.,” the story reports.

Sinclair and the FCC weren’t commenting.

“Sinclair, which has told reporters previously the violations were unintentional, disclosed the investigation in financial filings,” Reuters reports. “Sinclair, which owns more than 170 U.S. television stations and is the largest U.S. operator, announced plans in May to acquire Tribune’s 42 TV stations in 33 markets as well as cable network WGN America and digital multicast network Antenna TV, extending its reach to 72 percent of American households.”

The proposed acquisition is currently under review by the FCC and the Justice Department.