And the station-buying binge likely will continue. When Sinclair announced the Fisher acquisition this month, CEO David Smith responded to an analyst's question about whether acquisitions soon would be limited by a Federal Communications Commission rule that limits the reach of a single owner's stations to no more than 39 percent of U.S. households.
"We can do a lot more," said Smith, explaining that Sinclair's percentage of household coverage would fall well below the FCC threshold.
While its stations would reach about 34 percent of U.S. households, the FCC counts UHF stations as half of non-UHF stations, which would decrease Sinclair's calculated reach under the FCC rule, Smith said.
To some, however, Sinclair's appetite is proving worrisome.
Craig Aaron, president of Free Press, a group that advocates for diverse media ownership and criticizes consolidation, said he views several aspects of Sinclair's growth strategy as problematic.
"One is this merged newsrooms in all but name," he said. "The Sinclair model, in addition to the mass acquisitions, has been to set up shared-services agreements at the local level, where Sinclair is doing news for multiple stations, even though a number of them are owned by somebody else. It makes their reach even bigger. I think it's violating the spirit of what local TV is supposed to be."
Amy said Sinclair has more than 20 news-share arrangements but added that some of those involve other owners producing news that is carried on Sinclair-owned stations.
Wharton, of the National Association of Broadcasters, sees Sinclair's growth as a positive sign for the broadcast industry at a time when it faces what the group views as unfair competition from cable and other pay TV outlets.
"There are a number of broadcasters who are helping struggling stations produce more local news programming, and we think that's a good thing, rather than allowing a TV station that competes with cable to go out of business," Wharton said. "The fact that there are companies like Sinclair and others who are investing in the broadcast business is a positive for the future of free and local broadcasting."
Because of relatively new competition from cable and satellite TV companies, the association thinks the FCC needs to relax the ownership rules, which Wharton called " 'Leave it to Beaver' rules in a 'Modern Family' era."
As for Sinclair's growth, Wharton said, "If the goal is to have a healthy local television business providing programming free to the community, isn't that a positive for communities all over the country?"
Largest TV station owners
A list of the nation's top five TV station owners compared to Sinclair Broadcast Group once it completes its pending deals.
Name, headquarters, stations, 2012 revenue
Sinclair Broadcast Group, Hunt Valley, 134 stations, $1.06 billion
ION Media Networks, West Palm Beach, Fla., 60 stations, n.a.
Nexstar Broadcasting Group, Irving, Texas, 60 stations, $378.6 million
Entravision Communications, Santa Monica, Calif., 53 stations, $223 million
Raycom Media, Montgomery, Ala., 53 stations, n.a.
Source: company websites