Media watchdog Ofcom has submitted its report on News Corporation's takeover bid for broadcaster BSkyB to Culture Secretary Jeremy Hunt, it has said.
But the contents of the report will remain confidential for the time being.
Business Secretary Vince Cable asked Ofcom to advise if the plans would restrict the range of UK media voices.
But the PM passed responsibility for a final ruling to Mr Hunt after Mr Cable was recorded saying he had "declared war" on News Corp owner Rupert Murdoch.
Cabinet Secretary Sir Gus O'Donnell said the transfer would "ensure there was no conflict of interest" after the business secretary was secretly taped by undercover journalists.
Mr Murdoch's company, an international media giant which owns UK newspapers the Sun, News of the World, the Times and Sunday Times, already has a 39% stake in BSkyB. It is attempting to buy the remainder.
Rival media owners, including the heads of the Daily Telegraph and Daily Mail groups, the BBC, BT and Channel 4, complained the move could have "serious and far-reaching consequences for media plurality".
And if Ofcom raises concerns, it could pave the way for a lengthier and more detailed Competition Commission probe.
The bid has already been approved by the EU, which said it would not "significantly impede" competition in Europe.
An Ofcom spokesman said: "Ofcom can confirm that it has submitted its report into the public interest considerations to the Secretary of State for Culture, Media and Sport."
The watchdog would not comment on the details of the report until it was published by the government.