London - Russian painter Wassily Kandinsky's expressionist masterpiece "Studie zu Improvisation 3, 1909" was the highlight and leading indicator for a flat Christie's London Impressionist and modern art sale on Tuesday.

The painting fell short of its top estimate and a record for the artist at auction when it sold for just more than US$21 million (S$27 million), the world's largest auctioneers said on Tuesday.

The early 20th century artist's vibrantly coloured painting of a knight on horseback was the highlight of the sale and had a top estimate of US$24.19 million. A similar painting set a US$23 million record for Kandinsky's work last year.

The Russian expressionist was not the only leading light in an auction series of 44 lots that also included works from Pablo Picasso, Henry Moore, René Magritte, Amedeo Modigliani and Paul Signac.

The auction total for the evening of 64.07 million pounds (US$100 million) fell short of a pre-sale top estimate of 75.8 million pounds but was well above the low estimate at 52.8 million pounds.

That was slightly down from the auction house's performance for the same sale category in New York a month ago, where Christie's met expectations with a total of US$160 million and a record was set for French artist Chaim Soutine of US$18,043,750 for his circa 1927 oil "Le Petit Patissier."

Jay Vincze, Christie's London international director and head of Impressionist and modern art, called Tuesday night's sale results "solid" and said it displayed continuing strength in selling rates.

"There was great depth of bidding on works of high quality at all price levels, with strong participation from many new and existing collectors from both traditional and growth markets, including Greater China and India," he said in a statement.

"Studie zu Improvisation 3, 1909" belongs to Kandinsky's revolutionary series of paintings, started earlier that year, known as "Improvisations," which mark his first major forays into the realm of abstraction.

The romantic image of a lone knight preparing to storm the citadel is a clear and repeated symbol in Kandinsky's art of the dawning of a new age, of the coming of the Apocalypse and of the ultimate Resurrection of the spirit that would, Kandinsky believed, inevitably follow it.

Among the highlights of the other lots in the sale, Modigliani's portrait of his art dealer Paul Guillaume, one of only four, went for 6.7 million pounds, shy of its top estimate of 7 million pounds.

Picasso's 1960 "Femme Assise Dans un Fauteuil" edged just over its top estimate by going for 6.1 million pounds. It is one of a group of portraits of his partner Jacqueline Roque.

There were three Moore sculptures up for sale. His 1944 "Family Group" earned 337,875 pounds against a top estimate of 500,000 pounds. A 1978-80 "Reclining Figure No. 7" earned 1.4 million pounds against a top estimate of 1.8 million pounds while his granite abstract "Stone Form" made in 1984, earned 1.4 million pounds, about 400,000 pounds short of its top estimate.