Francis Bacon's Study for Self-Portrait, which depicts himself and friend Lucian Freud as a single entity, is coming to auction in London on Wednesday, June 27.
It is the only full-length Bacon self-portrait to combine his face with the body of his friend.
Although no estimate has been given by auction house Christie's for the 1964 piece, we believe a figure of £25m is not out of the question, considering the great demand for Bacon's work.
His 1976 Figure Writing Reflected in Mirror sold for $44.9m (£28.7m) at Sotheby's New York in May, up 12.2% on its $40m high estimate, while a triptych of Freud by Bacon made £23m at Sotheby's in February 2011.
Bacon and Freud met in 1945 and painted each other on a number of occasions.
The recent surge for Bacon has been mirrored in the post-war and contemporary art sector as a whole, which witnessed growth of 35% in 2011.
Bacon lovers will also be in attendance at Sotheby's London the previous evening, where a 1980 Study for Self-Portrait will appear, valued at a more modest £5m-7m.
Painted in 1980 and regarded as one of the most stunning of Bacon's self-portraits, it was previously part of the Stanley Seeger collection.
Triptych 1976 remains Bacon's most valuable work. It sold for $86.3m to Russian billionaire Roman Abramovich in 2008.
Christie's June 27 auction will also feature an untitled work by Jean-Michel Basquiat, which could well break the US artist's $16.3m world record.
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