(Reuters) - The clock could be running out for billionaire William I. Koch in a lawsuit against Christie's in which he accused the auction house of fraud over his purchase of wines said to have been owned by third American president Thomas Jefferson. A federal appeals court panel in New York on Wednesday questioned whether Koch had conducted timely due diligence when doubts were raised about four bottles of 1787 wine engraved "Th.J" that were sold to him in 1987 and 1988 by dealer Hardy Rodenstock through intermediaries.