An abstract portrait by Pablo Picasso on Wednesday smashed the record for an artwork sold in Australia, netting A$6.9 million ($6.1 million) at an auction in Sydney.

The 1954 painting "Sylvette", which clearly showed the ponytail and young face of model and later successful artist, Sylvette David, amid bright swathes of red, yellow and green, was sold to an unidentified phone bidder.

"Sydney is the New York of the art market in the southern hemisphere," Deutscher-Menzies Galleries spokeswoman Marie Geissler told Reuters, adding the sale proved Australian galleries could sell works internationally.

The Picasso easily broke the country's previous record of A$3.48 million, paid for a work last year by Brett Whiteley, the late wild-haired bad boy of Australian Art.

Australia has been experiencing a year-long boom in art sales, driven by cashed-up collectors involved in the country's China-driven mining boom.

Rodney Menzies, the chairman of Menzies Art Brands, bought the Picasso two years ago for $4,608,000 and had tipped strong overseas interest in the painting from Asia and Europe.

Sylvette David featured in more than 40 pieces by Picasso after sitting for him while living as a 17-year-old at Valories in the south of France. Her tall frame and long, blond ponytail fascinated the Spanish cubist painter, who died in 1973.