NEW YORK.- Among the freshest and most immediate works by one of the finest US artists of the 19th century, John Singer Sargent (1856 -1925), are his late portraits, especially of children. One of these, Portrait of a Child - an incredible oil on canvas, portraying a young girl aged between around five and eight who is caught in a dreamy pose - is to be sold by Bonhams in New York on 28 November. It is thought to have been painted after 1900 and is expected to fetch $700,000-900,000.

The artist has depicted the little girl squirming in a formal armchair, with her arms interlaced awkwardly around the mahogany arm and stile. She appears to be completely bored and over-tired and her eyes plead from underneath her tousled locks of hair, as if to ask; "Can I go now?"

"The identity of the sitter is unknown and the work does not appear to be a study for any other portrait. However, a number of Sargent's late portraits of children that relate in both style and pose, and perhaps the most interesting of these is that of Marian Roller," says Alan Fausel, Bonhams' director of 19th century paintings in New York.

"The child is adorned in a profusion of white, nervously clutching her doll and is strikingly similar in her physical attributes, to the sitter in Bonhams' painting," adds Fausel.

Marian was the daughter of Sargent's London framer and restorer Harold Roller and his wife Nettie.

After Sargent's demise, Harold's brother and business partner, George, framed and restored the work to be sold by Bonhams, and, in 1928, was quoted in the Daily Sketch saying that the portrait was 'quite one of the cleverest child pictures Sargent ever painted'. It is not known if this remark was inspired by familial pride.

Sargent's friend and fellow artist Violet Garrard (the inspiration for the character Maisie, in Rudjard Kipling's novel The Light that Failed) discovered the portrait, after his death. Garrard. The artist's sisters had given her 'a batch of canvases, old paints and other materials' from the studio. When she found the present work amongst the group she contacted the sisters who insisted she keep it as a gift. Queen Helen of Romania later owned the work before it came into the possession of its present UK-based owners.

Another painting by Sargent, a deaccessioned work from the San Francisco Museum of Modern Art, can also be found within the sale. The oil sketch for a larger portrait of Captain John Edmund Spicer, High Sheriff of Wiltshire and a captain of the First Life Guards, is dated 1901 and is expected to fetch $100,000-150,000. Captain Spicer was married to another of Sargent's subjects, Lady Margaret Fane - the youngest daughter of the 12th Earl of Westmorland.

The finished version shows the captain as a country gentleman about to go out for a carriage ride. He holds a hat, gloves, and a driving whip in his left hand while his right is partially tucked into his jacket pocket with a colorful red and green handkerchief dangling below. However, these items are merely hinted at in the sketch, as it is a loose and thinly painted work.