NEW YORK CITY.- Christie's has reported total 2001 auction revenues of $1.8 billion, beating out Sotheby's, which reported $1.6 billion in auction sales. But both houses had a drop in total sales from the preceding year, 23 percent from $2.1 billion at Christie's and 16 percent from $1.9 billion at Sotheby's. The drop in business was attributed to the events of Sept. 11, 2001. Sotheby's net loss improved, from $41.7 million in 2000 to $19.1 million in 2001; Sotheby's president William Ruprecht said he expects the company to return to profitability next year, and attributed the fourth-quarter decline to "irrational competition" from boutique auctioneer Phillips, de Pury & Luxembourg, which is widely thought to have paid excessive amounts to consignors to obtain top-notch art for its sales.