World's most expensive book for $10m

A COPY of the world's most expensive book, which features life-sized prints of flamingoes and swans, is tipped to fetch up to STG6 million ($A10.02 million)at auction in Britain, Sotheby's said.

John James Audubon's seven-volume Birds Of America, which dates from the 19th century, will be sold alongside literary treasures like a copy of William Shakespeare's First Folio and a series of letters by Queen Elizabeth I.

There are thought to be just over 100 copies of Audubon's huge book - which measures around 90 centimetres by 60 centimetres - still in existence and another sold for $US8.8 million ($A9.54 million) 10 years ago.

Before painting the birds, Audubon shot them and hung them on a wire.

All of the works belonged to a British book collector, Lord Frederick Hesketh, who died 55 years ago, although his collection is only now being sold off by the trustees of his will.

The whole collection could sell for up to STG10 million ($A16.7 million) in a sale at Sotheby's in London on December 7.

David Goldthorpe of the auction house said: "The sale offers the twin peaks of book collecting - the most expensive book in the world, Audubon's Birds of America and the most important book in all of English literature, Shakespeare's First Folio.

"We are thrilled to be offering such a diverse and remarkable collection."