The Impressionist and Modern art sales in London are traditionally the highest earners for both Christie’s and Sotheby’s, and this year’s sales in February are estimated to yield a robust $200 million combined. “It’s business as usual,” the London head of Impressionist and Modern art at Christie’s, Olivier Camu, said, “but ‘usual’ has been strong for four or five years.”

But jitters in Britain connected to tumbling house prices, high interest rates, and signs of increasingly fragile economic prosperity continue. Can London command the prices seen last June at sales that broke all European records? Yes, for several reasons.

First, the art market has proved to be detached from the financial markets. Mr. Camu is not worried about the credit market turmoil, which he defined as a specific market. “All the art market measures are fine,” he said. Furthermore, many of the new breed of collectors — Russians and those from the Middle East — have homes in London and bolster the sales by attending them. Finally, and perhaps most important, the art market has gone truly global, and experts from both houses say that selling top art these days is all about when, not where. “The major pictures will be getting their full price wherever they are sold, be it London or New York,” the vice chairman of Impressionist and Modern art of Sotheby’s, Helena Newman, said. “The money’s there.”

So are the rich pickings. Both houses are particularly excited about their German Expressionist offerings, as this area has shown extraordinary growth in the past year; two paintings by Franz Marc and Lyonel Feininger went for more than $20 million each last June. Much buzzed about at Christie’s is an exquisite set of eight Egon Schiele works on paper (1910–18), each estimated at between $3 million and $4 million, sold to benefit the Neue Gallery in New York. Mr. Camu praised their “bold, nervous lines” and “erotic, shocking, and entirely modern” depictions of bruised-looking bodies wrapped in elemental unions. Schiele’s preoccupation with the life cycle is most powerfully present in the 1910 beige and white “Mutter und Kind” (“Mother and Child”), with its sexy, haloed young mother and clinging, faceless toddler. Also set to do very well are a couple of works by the Russian-born Expressionist, Alexej von Jawlensky. “Hélène” (1911), a lustrous, intriguing portrait of the artist’s future wife, and “Mädchen mit roter Schleife” (1911), of a sullen, richly pouting young girl with a red bow, are both estimated at between $3.4 million and $5 million. Mr. Camu anticipated interest from nationalistic Russian buyers, eager to claim works by homegrown artists such as Jawlensky and Kandinsky.

The German presence is also strong at Sotheby’s, which for the first time will host the sales unaccompanied by Contemporary auctions in the same week (as in New York, the latter will stand alone later in the month). Here, there is an iconic work from Marc’s series of red horses: “Weidende Pferde III” (“Grazing Horses III”), estimated at between $12 million and $16 million. An intense and vivid showcase of the artist’s obsession with nature, the work offers a glimpse of Orphism, a school in which color and form alone convey meaning. Also expected to cause a stir is Jawlensky’s 1910 portrait of a girl — “Schokko” — who got her name by insisting on a cup of hot cocoa before posing sessions (estimated at between $13 million and $17 million).

Star Impressionist works include the classic wintry Monet snowscape at Sotheby’s, “La Route de la Ferme Saint-Siméon en hiver” (1867), estimated at between $6 million and $8 million. There is also an iconic 1874 Renoir, “La Loge ou L’Avant-scène,” of theatergoers peering out from their box, estimated at between $5 million and $7 million. At Christie’s is Paul Signac’s grand view of Paris, “Pont des Arts (Paris),” a 1925 oil, estimated at between $7 million and $9 million. The piece is in good company with top-drawer work by Monet, Pissarro, and Degas.

Both houses will be selling Picassos in their Modernist collections, alongside works by Juan Gris, Matisse, and Mondrian. A standout at Sotheby’s is one of the best portraits by Picasso of Dora Maar, his lover and muse in the ’30s and early ’40s, estimated at between $13 million and $17 million. At Christie’s, a highlight is a late self-portrait, “Homme assis au fusil,” which captures the animalistic masculinity of the artist’s earlier days, and is estimated at between $10 million and $14 million.

Surrealism commands its own sale at Christie’s, with 35 lots of excellent painting by artists including Magritte, Picabia, Joan Miró, Kandinsky, and Max Ernst. Magritte’s soft-hued “Spring” is unusually poetic, estimated at between $2 million and $3 million. At Sotheby’s, in addition to more predictable classics, are a small but classic Mondrian work on paper, in red and blue (estimated at between $2 million and $3 million), and another unusual Magritte — a bottle, hand-painted by the artist with surrealist clouds, estimated at between $200,000 and $300,000.

These sales cover vast artistic terrains, and there are meaty offerings across the board. It remains to be seen if the final reckonings next month can match the sums made by their predecessors in June. But if the indicators — stiff demand and high-quality supply — are to be believed, there’s a good chance they will.