Tinkler, who has a history of making countercyclical calls on assets purchases with his investment in Macarthur Coal and his acquisition of Maules Creek from Rio Tinto, may have overextended himself on this occasion, with his $5.20 per share offer for Whitehaven well above its current trading price of $3.48.

A response from Tinkler was not available to ILN by publication time.

Tinkler’s future with Whitehaven is now in doubt. The highly geared Tinkler, who is a 21.4% shareholder, may have to sell his stake at firesale prices if the Whitehaven shareprice continues to decline through short selling.

Tinkler, who now resides in Singapore and holds $500 million of personal debt, was believed to be seeking Asian partners to back his takeover of Whitehaven which comes just weeks after it successfully merged with his Aston and Boardwalk Resources companies.

“On 10 August 2012, Whitehaven Coal announced that it had granted the Tinkler Group access to due diligence in order to further develop an indicative and non-binding proposal for a Tinkler Group-led bid vehicle to take Whitehaven private for $5.20 cash per share,” Whitehaven said in a statement this morning.

“The due diligence period expired yesterday and Whitehaven has now been advised by the Tinkler Group that a formal binding proposal of $5.20 cash per share will not be forthcoming. Accordingly, the data room has been closed and the due diligence process has now ended.

“While the Whitehaven board will always assess carefully firm proposals which are in the best interests of shareholders, the board and management remain focused on developing the company’s portfolio of high quality coal assets to deliver value for all shareholders.”