SYDNEY (Reuters) - A cheeky artist who uses his penis as a brush has entered a racy self-portrait for Australia's top art prize.

Australian Tim Patch, who calls himself Pricasso, usually exposes his talents at sex product fairs around the world, but has decided to go upmarket by entering a painting for Australia's Archibald Prize -- the nation's top award for portraiture.

In a unique painting style, Patch does not use paint brushes, but his penis to apply paint to the canvas.

"I had to use my bum to paint in the background, because you have to have the occasional break," Patch told the Sydney Morning Herald newspaper on Wednesday.

Patch entered a painting of a plastic surgeon in last year's Archibald Prize, but failed to impress the judges. This year's entry depicts a nude Patch, wearing only a hat, holding a blank canvas to hide his "brush".

The Art Gallery of New South Wales in Sydney expects up to 700 portraits to be entered for the 2008 Archibald Prize, with the finalists to be announced in March.

(Reporting by James Grubel; Editing by Michael Perry and Jerry Norton)