Billionaire mining magnate Gina Rinehart has quit the board of the Ten Network, and will be replaced by her alternate director John Klepec.

Ms Rinehart has cited increasing responsibilities in her Hancock Prospecting group, particularly the “Roy Hill Project” – one of the largest construction undertakings in mainland Australia.

Speculation has been building that Australia’s richest woman, who has been on the board since December 2010, could quit, retaining her 10 per cent share in the company, and appointing someone else to replace her.

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Mr Klepec had been increasingly attending board meetings on behalf of Ms Rinehart, attending 10 in the past year. He has been the chief development officer for Hancock Prospecting since 2009.

TEN’s executive chairman and managing director, Hamish McLennan, released a statement thanking Ms Rinehart for her contributions to the company.

“It has been a very great pleasure working with Mrs Rinehart and I have appreciated her commitment and our discussions. I look forward to her ongoing involvement,” Mr McLennan said.

He welcomed Mr Klepec’s appointment.

“John has a wealth of experience in the business development area, having served with BHP Billiton Limited, Mayne Group Limited and the BGC Group, prior to his current appointment with Hancock Prospecting,” Mr McLennan said.

“We welcome John to the Board and see his appointment as a Director of the Board of TEN as providing continuity following his role as an alternate Director for Mrs Rinehart at TEN.”