WASHINGTON — The day before President Trump’s inauguration, the top executive of the Sinclair Broadcast Group, the nation’s largest owner of television stations, invited an important guest to the headquarters of the company’s Washington-area ABC affiliate.

The trip was, in the parlance of the business world, a deal closer.

The invitation from David D. Smith, the chairman of Sinclair, went to Ajit V. Pai, a commissioner on the Federal Communications Commission who was about to be named the broadcast industry’s chief regulator. Mr. Smith wanted Mr. Pai to ease up on efforts under President Barack Obama to crack down on media consolidation, which were threatening Sinclair’s ambitions to grow even bigger.

Mr. Smith did not have to wait long.

Within days of their meeting, Mr. Pai was named chairman of the F.C.C. And during his first 10 days on the job, he relaxed a restriction on television stations’ sharing of advertising revenue and other resources — the exact topic that Mr. Pai discussed with Mr. Smith and one of his business partners, according to records examined by The New York Times.

“These are invaluable and effective tools, which were taken away by the commission,” according to a summary of their meeting filed with the F.C.C.