* Mulsanne Resources to be wound up over $29.6 mln debt
* First time a Tinkler company has been liquidated
* Court action exposes Tinkler's finances to scrutiny (Updates with detail, comment from Tinkler Group, Blackwood)
By Jane Wardell
SYDNEY, Nov 20 (Reuters) - Liquidators have been appointed to a private company owned by struggling Australian mining magnate Nathan Tinkler over a A$28.4 million ($29.6 million) debt, exposing the coal baron to extensive scrutiny of his finances.
The New South Wales Supreme Court ordered on Tuesday that Mulsanne Resources Pty Ltd be wound up, suspending Tinkler's powers as a director of the company and giving liquidators access to its books to recover the money owed to junior coal company Blackwood Corp Ltd.
A former coal mining electrician, Tinkler, 36, turned a A$1 million bet on a coal deposit into a billion dollar fortune, spending millions on racehorses and sports clubs. But his wealth has plummeted as coal prices have slumped.
The court order marks the first time one of Tinkler's many companies has been liquidated. He has previously avoided wind-up actions against a number of his other companies by settling out of court at the last minute.
"The Tinkler Group has no comment but stresses the liquidation of Mulsanne Resources Pty Ltd does not affect our other operations," Tinkler's umbrella company said in an emailed statement.
If liquidators find that Mulsanne does not have enough assets to cover the Blackwood liability, Tinkler could face charges or fines for insolvent trading under Australian corporate law.
Blackwood, which has a current market value of less than A$25 million, turned to the courts after Tinkler failed to pay for a one-third stake in the coal explorer that he agreed to buy in July.
The company planned to use the funds to pay for drilling of its coal tenements, and sought the court wind-up order after talks with Tinkler over the payment failed.
A source close to the talks, who was not authorised to speak on the record, said Tinkler had been unable to provide a guaranteed payment plan.
Blackwood said it would monitor the investigation by the court-appointed liquidators from Ferrier Hodgson Chartered Accountants. Its shares plummeted 25 percent to A$0.135 after the court decision.
The liquidators are required to provide reports to creditors, which must be lodged with the Australian Securities and Investments Commission.
Tinkler's Ocean Street Holdings Pty Ltd and guarantor Buildev Pty Ltd agreed last month after the threat of legal action to pay property firm Mirvac Group A$17 million over a disputed land purchase.
A trio of other Tinkler firms - Tinkler Group Holdings Pty Ltd, Hunter Ports Pty Ltd and Bolkm Pty Ltd - also agreed in October to pay mining services company Sedgman Ltd a A$2 million debt to avoid a separate lawsuit.
Most of Tinkler's wealth is tied up in a heavily leveraged stake in Australia's largest independent coal miner, Whitehaven Coal. The value of that 19.4 percent holding has slumped to around A$600 million from A$1.1 billion at its peak.
The publicity shy Tinkler recently moved with his family to Singapore, and there are signs of trouble elsewhere in his diverse empire.
His horse breeding and racing company, Patinack Farm, said last week it will sell hundreds more of its horses and shut down a key stable to cut costs after a rapid expansion in recent years.
($1 = 0.9608 Australian dollars) (Reporting By Jane Wardell; Editing by Richard Pullin)