Sotheby's garnered revenues of $406.6 million for the first half of 2013, approximately matching last year's income from the same period, according to a quarterly financial report filed today by the publicly traded company. (Its main competitor, Christie's, is privately held.) Some $304.8 million was generated during the second quarter, which includes the big May auctions of Impressionist and modern and contemporary art.

While the house saw revenues climb $19.8 million because of an increase in fees the auction house charges its buyers, the report also indicates that Sotheby's lost money to "contracting sellers' margins," or sweeter deals given to sellers in order to secure their consignments.

Western auction houses and galleries are expanding into the Middle East and Asia to take advantage of burgeoning demand for art in those regions. The report indicates that some 22 percent of first-time buyers in the auction house's spring sales were from Asia. "Just five years ago, 21 percent of Sotheby's sold lots were purchased by buyers from ‘new markets'; today that figure is 39 percent—nearly double," the report says. Emerging markets include the Middle East, where Sotheby's held a contemporary art sale in April that brought $15.2 million, far exceeding its only previous contemporary art sale in the region.