At least six of Australia's biggest fund managers have offloaded large parts of their stakes in Fairfax Media over the last week.

Perpetual, 452 Capital, Maple-Brown Abbot, Lazard, UBS and Perennial have all sold down significant parts of their Fairfax Media shareholdings since May 8.

Some in the market have speculated the dramatic sell off was triggered by Rupert Murdoch's decision to sell down News Limited's entire 7.5 per cent holding in Fairfax.

"Rupert's decided Fairfax is not in play anymore. The blokes who might have been in there expecting something to happen after the media reforms have repositioned themselves," one analyst told InvestorDaily.

He added that after Fairfax Media and Rural Press's $9 billion merger last week the company was a "very different animal".

"Now there is some real management around in the form of John B Fairfax  . . . Fairfax is off the M&A radar."

Morningstar head of research Anthony Serhan had a similar view.

"[Fairfax shares] have always been viewed as expensive. The exit of News Limited from its register means there is less likelihood of takeover pressure," he said.

News Limited sold its stake in early May for $5.08 per share with the explanation that Fairfax no longer needed "any help from us in defence".

Shortly after, Fairfax finalised its merger with Rural Press to form a company worth $9 billion.

It meant Rural Press chairman John B Fairfax, a popular and respected member of the industry, now owns 14.6 per cent of his namesake.

Since then Lazard, 452 Capital and Perennial have ceased to be substantial holders in Fairfax Media, while Perpetual reduced its stake from 10.73 per cent to 7.41 per cent.

Maple-Brown Abbot reduced its stake from 8.43 per cent to 5.77 per cent and UBS reduced its share in Fairfax from 9.39 per cent to 6.22 per cent.

Perennial portfolio manager John Murray stressed that his fund's reduction in Fairfax was a minor portfolio realignment.

"We remain a very significant holder in Fairfax. We like the merger with Rural Press and remain very happy investors. This was simply portfolio realignment and there is no change in our fundamental view on Fairfax," he said.

Shares in Fairfax Media were trading at $5.04 each by late afternoon on Tuesday.