Australia's richest woman, Gina Rinehart, sold on Thursday part of her shares in Fairfax Media which had denied her a board seat.

However, even if she sold $50 million worth of shares, she is still Fairfax's largest stakeholder since she still owns 14.9 per cent of the firm, down from 18.7 per cent.

Perpetual, Australia's leading fund manager, bought the 86.5 million shares Ms Rinehart sold at 58 cents per share. It was a first media share purchase in a long time by Perpetual, which the fund manager said was at a reasonable value.

Hancock Prospecting, which holds the shares of Ms Rinehart, said the sale was not her way of getting back at Fairfax but to meet rules governing a corporate insurance policy designed by the company to protect directors from lawsuits by other shareholders. The policy, common among firms, excludes directors with more than 15 per cent stake in a company.

"The sale was completed to resolve an issue that arose concerning the Directors and Officers Insurance Policy, in the situation of a director having a greater than 15 per cent shareholding in Fairfax," Hancock said in a statement.

Hancock said that was one of the key issues against Ms Rinehart's attempt to get board seats that Fairfax Chairman Roger Corbett raised.

However, a Fairfax senior official said the door to the company's boardroom will continue to remain close to the world's richest woman because of her continued attack on Mr Corbett, who acts on behalf of the board.

The Fairfax officials said the main issue remains Ms Rinehart's attempt to gain control of editorial policies and her sale of part of her shares did not resolve the matter.

However, Perpetual hinted it may side with Ms Rinehart in the ongoing battle for board control.

"I don't think the existing board has covered itself with glory. We're not averse to a fresh set of eyes being on the board," Braidwood Times quoted Perpetual Portfolio Manager Charlie Lanchester.

Hancock said despite the partial sale of Ms Rinehart's shares in Fairfax, it will continue to monitor the performance of its investment in the media firm. It also denied speculations that Ms Rinehart would make an offer to take over Fairfax, which is the publisher of major Australian dailies such as The Age, The Sydney Morning Herald, The Canberra Times and the Australian Financial Review.