* Main Tinkler firm pays more than $500,000 ahead of hearing
* Two other Tinkler firms in liquidation this week
* Court actions raise questions over Whitehaven stake
* Another Tinkler company faces $163 mln suit (Updates after court hearing, changes dateline)
SYDNEY, Nov 23 The holding company of Australian mining magnate Nathan Tinkler avoided a winding-up claim on Friday after paying a creditor A$160,000 ($165,500), hours before a court hearing to consider appointing liquidators for the third time this week.
A winding-up action over Tinkler Group Holdings Pty Ltd would have dealt yet another blow to the 36-year-old coal baron, who has been grappling with a slew of lawsuits over commercial disputes and unpaid bills.
His financial troubles have raised questions over the future of his near one-fifth stake in Australia's largest independent coal miner Whitehaven Coal Ltd.
The latest creditor, Internet Fraud Watchdog, dropped its winding-up action at the New South Wales Supreme Court after Tinker Group paid the money owed, court costs and interest.
"It's good news, it's been a long and hard battle," Internet Fraud Watchdog's Executive Chairman Ken Gamble told Reuters on Thursday ahead of the hearing.
Internet Fraud Watchdog had been hired to protect Tinkler's reputation and provide personal security, Gamble said.
A second creditor involved in Friday's hearing, Gilbert + Tobin, was owed almost A$350,000 and was paid earlier this week, a spokeswoman with the law firm said.
Tinkler's spokesman could not be reached immediately for comment.
Tinkler's legal battles are not over yet.
Another of his companies, Aston Resources, is being sued for A$157.4 million by a former executive of the firm, Hamish Collins, who alleges Tinkler reneged on a promise to hand over the equivalent of 5 percent of the value of the company's main mining assets. A hearing is expected in the new year.
Tinkler has managed to settle some lawsuits on the court steps to avoid liquidation or public exposure 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.
But he could not save Patinack Farm Administration Pty Ltd and Mulsanne Resources Ltd. Liquidators were appointed to the two companies this week, over debts totalling more than A$28 million.
A former coal mining electrician, Tinkler 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.
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 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 into equity.
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.
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.
On Thursday, Patinack's liquidator Anthony Matthews and Associates said it had reached a deal with the company over the jobs of more than 240 workers.
"I advise that following discussion with the management of the company that employees will not have their employment terminated," Tony Matthews said in a statement. ($1 = 0.9665 Australian dollars) (Additional reporting by Jane Wardell; Editing by Paul Tait)