Sinclair’s attempt to puchase Tribune Media may be in trouble after word surfaced Monday from Federal Communications Commission Chairman Ajit Pai that he has “serious concerns” about the $3.9 billion deal, CNN reports.

Pai released a statement saying: “Based on a thorough review of the record, I have serious concerns about the Sinclair/Tribune transaction. The evidence we’ve received suggests that certain station divestitures that have been proposed to the FCC would allow Sinclair to control those stations in practice, even if not in name, in violation of the law.”

CNN adds: “The FCC chair is taking issue with Sinclair’s plans to divest certain stations in order to win regulatory approval. Sinclair has announced deals to sell certain stations in major markets, but with the agreement, Sinclair will continue to operate the stations. Some buyers have a clear connection to Sinclair: In Houston and Dallas, the buyer is Cunningham Broadcasting Co., a company named after and controlled by the estate of the mother of Sinclair’s executive chairman, David Smith.”

Sinclair Broadcast Group is already the largest owner of local TV stations in the U.S., and is attempting to become even larger.

“The deal would mean Sinclair’s stations would cover a majority of the country,” CNN notes. “The deal requires approval from the FCC because it involves broadcasting licenses and local stations.”