(IBTimes) - The world's second largest wine producer, Australia's Treasury Wine Estates, is being bid for by some of the world's largest buyout firms, with news a $3.2bn joint offer from KKR and Rhone Capital has been equalled by another global private equity player.

The sydney-based owner of wine brands Penfolds, Lindemans and Beringer Vineyards has received a second unsolicited bid from a global private equity firm, according to a TWE statement, a week after KKR and Rhone Capital proposed a joint A$5.20 a share offer for the Australian firm.

The Treasury statement did not comment further on the second bidder's identity.

But media reports, quoting unnamed sources, said the buyout firm behind the second proposal was Texas, US-based TPG Capital.

Pursued by Reuters, a Treasury spokesman said the second suitor made its approach over the weekend and asked not to be named.

Goldman Sachs, which is advising Treasury, refused to comment.

Treasury Wine's stock finished 3.9% higher in Sydney, valuing the winemaker at A$3.45bn ($3.2bn, £1.9bn, €2.4bn).

"The Board of TWE has concluded that it is in the interests of its shareholders to engage further with [the second suitor]. Therefore, subject to the negotiation of an appropriate confidentiality agreement, it will also be granted the opportunity to conduct non-exclusive due diligence," the statement added.

"A deal will probably get done once you have this much interest in the business," Craig Young, who helps manage assets worth A$24bn at Tyndall Investment Management in Sydney told Bloomberg.

New York-based Rhone Capital joined KKR in making a revised bid for Treasury earlier in the month, after the winemaker's Board rejected KKR's $2.8bn bid tabled in May.

The revised bid represented a premium of 40.9% to TWE's closing share price on 15 April, 2014 of A$3.69 per share, according to a 4 August TWE statement.