* Patinack-related firm to be wound up over A$17,000 debt
* Follows liquidation order on Tues for another Tinkler firm
* Court action exposes Tinkler to personal liability
* Tinkler faces another potential wind-up action on Friday
By Jane Wardell
SYDNEY, Nov 21 Liquidators were appointed for the second time in as many days to a company owned by Australian mining magnate Nathan Tinkler, deepening the young tycoon's financial troubles in the wake of his failed bid to take Whitehaven Coal private.
A court ordered liquidators for Patinack Farm Administration Pty Ltd, one of 12 firms associated with his horse racing business, over an unpaid debt of A$17,000 ($17,600). A spokesman for Tinkler said, however, the amount had now been paid in full and the coal baron would be filing to reverse the order.
But the action, coming just after an order to wind up another unit, Mulsanne Resources Ltd and ahead of a similar hearing on Friday, has exposed to Tinkler to personal liability and raised questions over the future of his 19.4 percent stake in Whitehaven, Australia's largest independent coal miner.
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, sports clubs, luxury homes and fast cars.
But coal prices have since slumped and his stake in Whitehaven, a holding that represents the bulk of what remains of his wealth, has shrunk to below A$600 million from A$1.1 billion at its peak.
Sources have previously told Reuters the stake is heavily leveraged and lenders have been looking at options including pressing for the sale of shares or converting some of the loans to equity.
"The options seem to be running out," said Matthew Trivett, an analyst at Patersons Securities in Brisbane.
Trivett said there shouldn't be a lack of buyers at Whitehaven's current price of around A$2.80, down from a 2012 peak above A$5.60 in April.
"At current levels, Whitehaven looks quite attractive for large funds," he said.
In August, Tinkler pulled a $5.5 billion bid to take the company private, with sources saying he failed to raise enough equity to finance the deal.
On Tuesday, the New South Wales Supreme Court ordered that Mulsanne, also a private company, be wound up over a A$28.4 million debt owed to junior coal company Blackwood Corp Ltd over a stalled shares deal.
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.
Tinkler's main company, Tinkler Group Holdings Pty Ltd, is also facing a potential wind-up action by security firm Internet Fraud Watchdog at a court hearing scheduled for Friday.
Tinkler had managed to settle other lawsuits on the court steps to avoid liquidation or a public expose of his finances. In those deals last month, Tinkler's companies paid A$17 million to property firm Mirvac Group and A$2 million to mining services company Sedgman Ltd.
The Tinkler Group said the liquidation of Mulsanne did not affect its other operations, which include the Hunter Sports Group, the owner of The Jets A-league soccer team and home to former England striker Emile Heskey, but declined to comment further.
Tinkler, who had long held a dream to make it big in the "sport of kings", had splashed out more than A$300 million since 2007 to build his Patinack horse racing business, including A$19 million on 59 horses at one sale in 2008.
Last week, Patinack said it will sell hundreds more of its horses and shut down a major stable to cut costs after a rapid expansion in recent years.
Tim Allerton, Tinkler's Sydney-based spokesman, said the debt over workers' compensation cover owed by the farm's administration unit to the state of Queensland was due to an administrative error made by an associate company.
($1 = 0.9640 Australian dollars) (Editing by Lincoln Feast and Edwina Gibbs)