Mr Murdoch and Bruce Gordon, who owns regional broadcaster WIN, are a step closer to buying Network Ten out of administration after the competition watchdog said the move would not lessen competition.

The deal still relies on federal parliament passing new media ownership laws and, in particular, retracting the two-out-of-three rule, which prevents one person controlling newspapers, radio and television in a single market. While Pauline Hanson's One Nation party will support the new laws in exchange for closer scrutiny of the ABC, the government is yet to secure enough votes.

Australian Competition and Consumer Commission chairman Rod Sims said in considering the takeover, it focused on Mr Murdoch's assets because it did not detect any problems with Mr Gordon merging WIN with half of Ten.

Mr Murdoch is co-chairman of News Corp, which owns 70 per cent of Australia's newspapers and half of Foxtel, and his investment company, Illyria, owns the Nova radio network, which includes SmoothFM, FiveAA in Adelaide and Star104.5. The ACCC found a combined Ten and Foxtel news service would still be weaker than its competitors, and Illyria's radio stations carried little news content.

The ACCC received about 50 submissions, but there "wasn't a lot of concern" expressed, according to Mr Sims.

"We looked at this really carefully. I personally spent an enormous amount of time on this transaction because I am acutely aware that people will look at this as a loss of voices in the community," Mr Sims said.

Research found Seven and Nine have five times more journalists than Ten, and the ABC has nearly 10 times more.

"When I first looked at it I said "ooh, this will be problematic". But when you look at it in each of its components, it turns out not to be," Mr Sims said.

"Yes, this is a Channel Ten coming together with Sky News, [but it] is pretty small in terms of its viewership ... ABC, Seven and Nine are much bigger, and you have got SBS there as well."

While News Corp has a substantial print and online audience, Mr Sims said its main competitors - Fairfax Media, ABC, Seven, Nine and other online news sources - would keep its influence in check. Fairfax publishes The Sydney Morning Herald and The Age.

Labor's communications spokeswoman, Michelle Rowland, said the ACCC's approval confirmed the importance of ownership rules.

"As an economic regulator, it is not the job of the ACCC to look at issues of pluralism in forming a view on whether a merger will result in a substantial lessening of competition in a market," she said in a statement jointly issued with South Australian senators Penny Wong and Don Farrell.

Labor supports the government's proposed reforms, but not scrapping the two-out-of-three rule. However, the laws will pass if crossbench senator Nick Xenophon votes in favour.

"With the proposed changes, media diversity in Adelaide may quickly fall to the minimum number of voices ... If Foxtel, Nova, Ten and the 'Tiser end up carrying the same news, South Australians will have Nick Xenophon to thank for it," the Labor senators said.

PPB Advisory is in charge of Ten's sale and reportedly has a number of interested buyers.

Mr Sims admitted the ACCC's approval was based on the current size and influence of media companies.

"It's hard to see Nine and Seven disappearing off the face of the earth. And I hasten to add it's very important that you have got a strong Fairfax there - that is important to us and we have assumed that - and it's very important you have got a strong ABC there - that is important to us and we assumed that."

The deal may not have gotten the ACCC's green light at all if Mr Murdoch's radio stations, Nova and SmoothFM, were stronger on talkback than greatest hits.

"If you are interested in who is disseminating news and opinion, I think you will probably find the Macquarie Media network was considerably bigger and that's owned by Fairfax of course. And then you have still got the ABC," Mr Sims said.

Macquarie Media owns talkback stations such as 2GB in Sydney, 3AW in Melbourne and 4BC in Brisbane.

The chief executive of regional broadcaster and radio owner Southern Cross Austereo, Grant Blackley, said he "will watch with interest whether Mr Murdoch and Mr Gordon end up with the Ten asset and I guess we will judge it accordingly at that point in time".