London-based Christie’s, which is owned by the French billionaire Francois Pinault, had a great year in 2006. The world’s largest auction house “sold $1.26 billion of impressionist and modern-art pictures in 2006, including four Gustav Klimt paintings recovered by Nazi victims’ heirs. Postwar and contemporary auctions rose 59 percent, to $829 million. Worldwide, auctions rose ‘more than 30 percent’ from last year’s $3.2 billion, though final totals aren’t yet available.”