Shares in Whitehaven Coal (ASX:WHC) have soared to a record high on the likelihood of being the target of a $3 billion takeover bid from US firms.

The New South Wales coal producer finished 23¢ higher at $6.36 a share after refusing to revealing details on speculations that its biggest shareholder, US investment group First Reserve Corp (27 per cent), wa

s to join US coalminer Alpha to make a bid.

"Whitehaven confirmed that the company has had a data room in place for a long period of time for use in relation to various potential transactions," the company said in a statement send to Reuters.

Last week, the company told the ASX it is continuing talks with third parties in relation to potential corporate transactions.

''Those discussions that are continuing are preliminary and remain incomplete, and it is highly uncertain whether they will lead to a proposal for consideration by the company's directors and shareholders,'' Whitehaven said.

The speculation has assured that any takeover bid for the Australian coal producer will be from a much higher starting point. Whitehaven's market value has climbed by $920 million, or 41 per cent since early July.

This upward movement is credited to the takeover speculation as well as to a re-rating of Whitehaven's takeover appeal in light of the fancy valuations placed on coal assets in other transactions.

Monday's moderate 3.7 per cent increase for Whitehaven shows the market believes its strategic appeal to potential predators is about fully priced its shares.