A Picasso portrait of Dora Maar that Sotheby's estimates may fetch as much as 8.5 million pounds ($16.6 million), will lead the auction house's Feb. 5 sale of impressionist and modern art in London. The Picasso is one of seven guaranteed works in the 77-lot auction, Sotheby's said. The overall estimate is between 81 million pounds and 113 million pounds. Those figures are 2 million pounds above both the low and high estimates for Sotheby's February 2007 impressionist and modern sale, which featured 21 more items. Last year, the sale raised a mid-estimate 95 million pounds with fees, which at the time was a record for any auction in Europe, said Sotheby's, which has its main salerooms in New York and is incorporated in Wilmington, Delaware. Eleven percent of the buyers at the 2007 sale never bought at auction before. "This market has reached an interesting moment," said Simon Shaw, head of impressionist and modern art at Sotheby's, London, in a telephone interview. "We've been used to strong growth at sale after sale, but now the volume of new buyers at the highest level is slowing a little. I can't say this was the easiest auction to put together."The 1938 head-and-shoulders portrait of the artist's model and mistress, titled "Tete de Femme (La Lectrice -- Dora Maar)," has been entered by the heirs of the German collector, dealer -- and friend of Picasso -- Heinz Berggruen, who died on Feb. 23, 2007. Sotheby's said it was one of the few works left to the family by Berggruen, who in 2000 sold most of his collection to the German government. Expressionists Shaw said the London sale also features a section of German and Austrian expressionist art, including a consignment of 10 works entered by a German collector who had bought in the 1980s. The group includes one of the last Franz Marc "Grazing Horses" paintings left in private hands. "Weidende Pferde III (Grazing Horses III)," dating from 1910, is expected to fetch between 6 million pounds and 8 million pounds. The most highly estimated lot in the German and Austrian section is Alexej von Jawlensky's painting from around 1910, "Schokko (Schokko with Wide-Brimmed Hat)," valued at between 6.5 million pounds and 8.5 million pounds. In November 2003, Sotheby's New York sold the painting for a record $8.3 million with fees. In May 1989, at the height of the late 1980s art-market boom, a smaller version of Renoir's 1874 painting "La Loge" sold at Christie's New York for 10 times the lower estimate of $12.1 million. A private collector has again offered the smaller version at Sotheby's, London, now with an estimate of between 2.5 million pounds and 3.5 million pounds. "In recent years, the best impressionist prices have been achieved for later, more modern-looking works," said Shaw. Magritte Eyeball Among the postwar modern works on offer are the 1983 Henry Moore bronze, "Draped Reclining Mother and Baby," at between 3 million pounds and 4 million pounds, and the 1966 Rene Magritte painting, "La Misericorde," showing a suited man with a single eyeball for a head, valued at 600,000 pounds to 800,000 pounds. "There remains huge demand for great things if we can find them, but this is now a discerning market," Shaw said, when asked about the prospects for the sale in the current climate of economic uncertainty in the U.S. and Europe. Clients from emerging markets are the main source of new buyers of impressionist and modern art. "People in Russia, the Middle East and Asia are accumulating huge wealth. They're looking to put money in works of art."