News Corp's sale of its Perth Sunday Times and perthnow.com.au website to Seven West Media has been given the thumbs-up by the ACCC.

Australian Competition and Consumer Commission chairman Rod Sims, says after listening to concerns raised by advertisers, it decided the acquisition is "on balance", not likely to substantially lessen competition for consumers or advertisers.

A factor was the large decline in print newspaper readership, as WA consumers turned to online - where alternatives included dedicated Fairfax and ABC sites - and other sources for news.

Although some advertisers raised concerns about the loss of competition for advertising opportunities, most acknowledged that print advertising was of declining importance and identified other advertising options they could switch to if West Australian Newspapers tried to increase rates. "Advertising expenditure in print newspapers in Perth is in steep decline," Sims says.

"Most of the advertisers we spoke to after publishing the Statement of Issues (published on August 4) are spending less on print newspapers than a few years ago and are finding alternative ways of reaching target audiences, including via digital media."

Tim Worner, chief executive of Seven West - which publishes the West Australian - said the group would be "worthy custodians" of the Sunday Times, which was Rupert Murdoch's second acquisition "and dear to his heart".