The Nexstar American media group will become the largest local television operator after the Tribune Media deal for about $ 4.1 billion.
It comes three months after the Tribune's sale to Sinclair Group, currently the largest US local television operator, failed to handle regulatory barriers.
Full details were expected to be confirmed on Monday, but the deal was widely published in the United States on Sunday.
42 TV stations at Tribune reached about 50 million households.
The Chicago-based company also owns a national entertainment wired network of WGN America, with the reach of more than 77 million households, as well as a number of websites. It also has a stake in the food network.
Nexstar, based in Irving, Texas, owns, operates and provides sales and other services for 174 television stations that reach nearly 39% of all US television households.
Reuters, who first announced the deal, said the private equity of the US Apollo Global Management was also in talks with Tribune.
Tribune emerged from bankruptcy in late 2012 and in 2014 completed the passage of its newspapers.
The sale of Sinkler's company was a foul of the Federal Communications Commission of the United States (FCC) for promising to sell television stations. The regulator said Sinclair did not "fully reveal facts" about sales.
But it caused intervention by President Donald Trump, who wrote twitter in July: "It's so sad and unfair that the FCC will not approve the merger of Sinclair Broadcast with the Tribune. This was a big and much needed conservative voice for both people."
The news of many Sinclair TV stations is considered politically conservative.
Multiple TV broadcasts are excluded. The privately held Cox Enterprises in July announced that it is exploring strategic options, including the potential sale of broadcast television stations in cities such as Atlanta, Boston and Memphis.
It is also believed that Sinclair is performing other contracts, partnering with CVC Capital Partners in Private Equity to bid for regional sports networks that 21st Century Fox sells after the deal to merge most of its assets with Walt Disney.