Flagging fortune: Gina Rinehart slipped from 41 to 61 on Bloomberg's global wealth rankings.

Falling fortune: Gina Rinehart slipped from 41 to 61 on Bloomberg's global wealth rankings. Photo: Bloomberg

The net worth of Australia's richest individual, Gina Rinehart, has dropped by $3 billion to $16.95 billion after revenue and earnings slumped at her closely held iron-ore mining company Hancock Prospecting Pty Ltd.

Hancock submitted results for the year ended June 30 with the Australian Securities & Investments Commission. The filing was received by the regulator on November 1 and released to Bloomberg News on December 12.

Revenue slipped 14 per cent to $1.986 billion compared to a year ago, according to the filing. Net income plunged 85 per cent to $489.7 million. Earnings before interest, taxes, depreciation and amortisation slid to $1.1 billion, compared to $1.5 billion a year ago. Book value rose to $6.751 billion from $5.934 billion a year ago.

Rinehart's net worth was calculated using the Bloomberg Billionaires Index. More than half of the fortune stems from her ownership of West Perth-based Hancock, the holding vehicle for most of Rinehart's mining interests, including royalty rights she inherited from her late father, Lang Hancock, which guarantee her less than 1.25 per cent of all annual revenue generated by some of Hamersley Iron ore mines now owned by Rio Tinto Group.

Hancock also holds her 50 per cent interest in the Hope Downs mine, which she owns in a joint venture with Rio Tinto, and three thermal coal projects in Queensland. The company is valued using the average enterprise value-to-Ebitda multiple of four comparable publicly traded companies: Fortescue Metals Group Ltd, Vale SA, Rio Tinto and BHP Billiton Ltd.

Wealthiest Australians

Rinehart is listed at No. 61 in the Bloomberg wealth rankings, down from No. 41 on December 12. The next richest Australian is Crown Resorts gaming mogul James Packer at $6.1 billion, followed by Ivan Glasenberg, the chief executive officer of Glencore Xstrata Plc, who is worth $5.6 billion. Rounding out the top six billionaires in Australia are Frank Lowy, Harry Triguboff and Andrew Forrest.

Hancock spokesman Mark Bickerton said he wasn't immediately available to comment on Rinehart's net worth valuation.

Two of Rinehart's children - John Hancock and Bianca Rinehart - have sued to replace their mother as trustee of a family trust. In October, Gina Rinehart agreed to step aside from managing the trust, which holds almost 25 per cent of Hancock Prospecting shares. The trial is scheduled to resume in February.

Bloomberg