Federal regulators rolled back a series of decades-old regulations on Thursday, in a move that will make it far easier for media outlets to be bought and sold - potentially leading to more newspapers, radio stations and television broadcasters being owned by a small handful of companies.

The regulations, eliminated in a 3-2 vote by the Federal Communications Commission, were initially put in place in the 1970s to ensure that a diversity of voices and opinions could be heard on the air or in print. But now those rules represent a threat to small outlets who are struggling to survive in a vastly different media world, according to FCC Chairman Ajit Pai.

"Few of the FCC's rules are staler than our broadcast ownership regulations," said Pai. By eliminating them, he said, "this agency finally drags its broadcast ownership rules to the digital age."

One longstanding rule repealed Thursday prevented one company in a given media market from owning both a daily newspaper and a TV station. Another rule blocked TV stations in the same market from merging with each other if the combination would leave fewer than eight independently owned stations. The agency also took aim at rules restricting the number of TV and radio stations any media company could simultaneously own in a single market.

Reed: Why there are big local problems with Sinclair-Tribune Media's national deal »

A major beneficiary of the deregulatory moves, analysts say, is Sinclair, the conservative broadcasting company seeking to buy up Tribune Media for $3.9 billion. Tribune Media was the owner of the Chicago Tribune until the former Tribune Company split in two in 2014. The Chicago Tribune and its sister newspapers are now owned by Tronc.

"This has a huge impact," said Andrew Schwartzman, an expert on media law at Georgetown University. He added that the decisions will "reduce or eliminate" the need for Sinclair to sell off many stations in order to receive regulatory approval for the deal.

The FCC vote is the latest to ease regulations for the broadcast industry. It came the same day that the agency was expected to approve the deployment of Next Gen TV, a new broadcast standard that is ultimately expected to lead to improved audio and video quality on over-the-air television, as well as targeted advertising. And it came one month after the FCC voted to no longer require broadcasters to operate a physical studio in the markets where they are licensed.

The National Association of Broadcasters welcomed Thursday's vote.

"These rules are not only irrational in today's media environment, but they have also weakened the newspaper industry, cost journalism jobs and forced local broadcast stations onto unequal footing with our national pay-TV and radio competitors," the trade group said in a statement.

Under Sinclair, WGN could be 'Chicago's very own' no more »

Critics of the FCC repeal effort argue that the decision will lead to the concentration of power in the hands of a dwindling number of media titans.

"Instead of engaging in thoughtful reform," said Democratic FCC commissioner Jessica Rosenworcel, "this agency sets its most basic values on fire. As a result of this decision, wherever you live the FCC is giving the green light for a single company to own the newspaper and multiple television and radio stations in your community. I am hard pressed to see any commitment to diversity, localism, or competition in that result."

Senate Democrats this week called on the FCC's inspector general to launch a probe of the agency, over concerns that its impartiality with respect to Sinclair had been "tainted."

"This merger would never have been possible without a series of actions to overturn decades-long, settled legal precedent by Chairman Pai," wrote Sen. Maria Cantwell, D-Wash., and 14 other lawmakers in a letter. The letter added that Pai has "signaled his clear receptiveness to approving the Sinclair-Tribune transaction and in fact paved the way for its consummation."

Reed: Amid public outcry, feds should kill Sinclair bid to buy WGN owner Tribune Media »

The FCC didn't immediately respond to a request for comment. Sinclair declined to comment.

In his remarks Thursday, Pai said it was "utter nonsense" that his agency's decisions on media ownership would lead to a company dominating local media markets by buying up newspapers and radio stations.

"It will open the door to pro-competitive combinations that will strengthen local voices," he said, and "better serve local communities."