Revisions to how the agency calculates the audience reached by broadcasters would clear the way for Sinclair Broadcast Group Inc. to purchase Tribune Media Co., which owns KTLA-TV Channel 5 in Los Angeles and 41 other stations.

Thursday's changes, advocated by the agency's new chairman, Ajit Pai, and approved on party-line votes, reverse initiatives the FCC pursued under Democratic leadership during the Obama administration. Consumer groups and some lawmakers warned that the deregulation steps would trigger more media consolidation and higher prices for consumers.

The moves came as Pai is expected to soon try to roll back the controversial net neutrality rules for online traffic that were pushed through by former chairman Tom Wheeler.