The Nexstar Broadcast Group has steadily built its empire over the years, buying up television stations in large, medium and small markets alike. The group recently made an offer to purchase Media General, a group of television stations financed in part by Warren Buffet. The over 2 billion dollar offer was accepted and, depending upon FCC approval, will make Nexstar the single largest group of TV stations in America.
With 171 stations under its banner, Nexstar stations will be present in about 40% of all US TV markets. Why a television group must be this large is beyond me. When a station is owned by a group this large, so many outside interests can end up entering the news operations, simply because of obligations to advertisers. I remember a friend of mine who worked for a Fox O&O told me a story about how investigative stories about businesses had to be approved from the headquarters in New York to be green-lighted, because they did not want negative stories airing about current (or even potential) advertisers. And the Fox O&Os are not a very large group of stations; imagine having to have pieces approved through a myriad of advertising relationships with 171 stations.
As far as ownership goes, the playing field is getting smaller and smaller as far as TV stations go. Large groups such as Tenga, Raycom, Tribune, and now Nexstar, are purchasing stations in most major and medium-sized markets. I predict the aforementioned groups will eventually own the majority of TV stations in the US by the end of this decade.