Bruni's portrait, taken during her modeling days in 1993 by photographer Michel Comte, has attracted attention since she married French President Nicolas Sarkozy in February.

It is expected to fetch between $3 000 and $4 000 when it goes on the block on Thursday.

The photo is among some 140 images from German collector Gert Elfering. His collection also features work by Irving Penn, Richard Avedon, Helmut Newton and Peter Beard.

Four other photography auctions will take place on Thursday and Friday. They include collections by Arbus, known for her black and white portraits of people on the fringe of society, and Adams, the influential landscape photographer.

"The focus of Gert's collection has always been the great editorial photographers of the last half century, particularly in the world of fashion, celebrity, icons of beauty," Philippe Garner, Christie's international head of photos, said on Friday.

A portrait of 1950s and 1960s French screen siren Brigitte Bardot by Avedon was expected to sell for between $80 000 and $120 000.

Newton's photo of jewelry designer Elsa Peretti dressed in a Playboy bunny outfit and leaning on a New York terrace was valued at between $40,000 and $60,000.

Fifty-one Arbus pictures go on the block on Thursday. The collection includes a photo of three Russian midgets in a living room, and portraits of people taken on the streets of New York.

Mural-sized Adams landscapes including a dramatic image of a storm clearing over Yosemite National Park in California will be sold as part of an auction of 122 images on Friday.

The prints are from a California-based company that had amassed the largest private collection of Adams' work.