Publishing its response to a handful of questions proposed by culture secretary Jeremy Hunt in October, Ofcom said a review of media plurality should be conducted every four or five years.
The media watchdog pointed to special circumstances in which the exit of a news organisation could trigger a review.
But Ofcom said it “does not believe a prohibition on market share is currently advisable”, calling it “inflexible”.
Speaking to the Leveson inquiry last week, Labour leader Ed Miliband said it was wrong for one organisation to exercise overweening power, adding that News Corp’s command of 34 per cent of the market should be reduced to about a fifth.
Media plurality entered the spotlight during Murdoch’s attempt to buy the chunk of BSkyB he does not already own.
The divisive bid prompted Ofcom to undertake a consideration of plurality in 2010, in which it found that the existing framework for considering plurality might no longer be equipped to achieve the government’s policy objectives.
In its report released yesterday, the watchdog argued that the BBC should be included in an evaluation of media plurality, but that its current market position does not warrant a special review.
Ofcom said online news should be included in any review.
Alison Sprague, media specialist at FTI Consulting, said Ofcom has just thrown the decision “straight back to parliament”, offering a cautious response – “no doubt parliament would have preferred this to remain with the regulator.”