Gina Rinehart's stake in Fairfax is growing.

And the mining magnate is poised to ratchet up her demands for boardroom representation after buying yet another major parcel yesterday, industry insiders believe.

Mrs Rinehart is understood to be the buyer of about 70 million shares worth more than $40 million that changed hands in after-hours trading.

If so, it would take her holding to about 18 per cent. Another 20 million Fairfax shares were also traded yesterday.

The development comes just a day after another frenzied trading session, with speculation rife that Mrs Rinehart bought a $25.2 million parcel on Thursday.

She can buy up to 19.9 per cent of the publishing and broadcasting company without launching a takeover bid.

 

 

Analysts believe if Mrs Rinehart is the buyer, she is now unassailable in her campaign for two seats at the Fairfax board.

She has been engaged in a war of words with chairman Roger Corbett, who has resisted her boardroom campaign despite her status as Fairfax's biggest shareholder.

The latest raid came as an industry insider associated with Mrs Rinehart said the billionaire, after securing boardroom seats, would resist a push for the sale of key assets. Wielding her immense riches, she would also ensure Fairfax refinanced its debt on more favourable terms, the source said.

"She is determined now," he said. "There is a rumour that the board is selling out (internet auction site) TradeMe -- she would stop that in a flash."

In February, insiders told BusinessDaily she would ultimately acquire 19.9 per cent of Fairfax and make a tilt for Mr Corbett's role.

Mrs Rinehart, whose wealth is estimated at $29 billion, made her initial raid on Fairfax in January.

Speaking be