NEW YORK—“One more,” the auctioneer cajoled. “Last chance now.” During the sale of Impressionist and Modern art last night at Christie’s International, it seemed as though he was talking about more than the Henri Matisse on the rostrum. Jittery art sellers had packed this huge first sale of the fall auction season with paintings as if it were the last helicopter out of Saigon.

And perhaps it was.

All told, Christie’s raised an impressive $395 million, the second-highest total ever for an art auction. But the London firm offered 91 artworks in a single evening (70 is more common)—and only 81 percent of those sold. That compares to a giddier 93 percent at the same sale a year ago, and this time, a couple of trophies died on the block. The problem was obvious early on: The Russians weren’t coming.

This auction season, Christie’s, Sotheby’s International, and Phillips de Pury & Co. have staked much on Russia’s new wealth. Russian collectors have paid some of the top prices for art in the past two years, buying, among other works, Pablo Picasso’s Dora Maar au Chat, for $95.2 million in 2006, and Peter Doig’s White Canoe, for which Russian collector Boris Ivanishvili paid $11.3 million in June.

The auction houses have responded with new or expanded offices in Moscow, Russian tours of their paintings, and a new spiel. Christie’s Guy Bennett, head of the Impressionist department, made sure to point out that the company’s two priciest paintings this fall featured Russian subjects. One was a portrait of a Russian sculptor as painted by Amedeo Modigliani; another was of Lydia Delectorskaya, who served as a model for Matisse. Those two paintings sold for $30.8 million (against a high estimate of $25 million) and $33.6 million (high estimate: $20 million), respectively.

But the firm had also packed its sale with German Expressionist works, traditionally to Russian taste, and five paintings by Belarus-born Marc Chagall. And one by one, they failed to sell or sold low. A 1912 portrait by German artist August Macke, estimated at $15 million to $25 million, had no buyer; a Balthus and three of the Chagalls were similarly spurned. Meanwhile, the prices of Picassos, more to American taste, soared. At the final counting, despite the dollar’s record low against the euro yesterday, Americans bought half of the works on sale, Europeans 24 percent, and Russians a nearly nonexistent 1.5 percent (although that still might represent the biggest single purchase). Six months ago at Christie’s, it was almost exactly the opposite: Europeans and Russians—the groups were not broken up—bought half of the works on sale, Americans 29 percent.

Christie’s auctioneer Christopher Burge says “the Chagall market has plateaued” after a huge run-up, and that even he was surprised by the strength of the U.S. buying. “Our buyers are a movable feast,” he quipped. Art collector Larry Warsh, who is selling art—and plans to buy—at next week’s Christie’s sale, says the dollar’s weakness may actually have boosted American interest, as collectors begin to treat art as a “stronger currency” than the dollar. But last night’s results pose a problem for Sotheby’s, which holds a nearly $500 million Impressionist- and Modern-art auction this evening and has also tailored its sale to European and Russian tastes. Where the Russians are is still an open question.

One portent (and perhaps the next hot market to chase): Christie’s identified a hefty 21.5 percent of its buyers as “other,” meaning they were not from the U.S., Europe, Russia, Latin America, or Asia. This may reflect a surge in Middle Eastern buying. (Christie’s does not categorize the Middle East as Asia.)

Was it just a coincidence that two of the works that soared at the auction echoed Orientalist art, a 19th-century movement inspired by the Near East and Islamic peoples? Both the Picasso portrait of Jacqueline and Matisse’s of Lydia—which set a world record for the artist—featured the women dressed as odalisques, female concubines of the Ottoman Empire, as well as Middle Eastern costumes, themes, motifs, and patterning. Middle Eastern bidders may be stepping into the void left, permanently or temporarily, by their Russian counterparts. Late last week, Christie’s held hugely successful sales of Modern and contemporary art in Dubai, setting world records for dozens of Arab and Iranian artists.