Fairfax Media shares have plunged to a record low after mining magnate Gina Rinehart tried to reduce her stake in the company.

Gold was the best-performing sector on a day when the Australian stock market closed up a tick under 0.2 per cent.

Qantas Airways has posted its first loss since the airline was privatised 17 years ago, slumping to a $255 million net loss in 2011/12.

Origin Energy has warned that growth in its net profit will halt this year.