The titanic struggle for control of Artnet, the media and data company that provides a pivot point for the entire art market, was scheduled to come to a head at tomorrow’s annual general meeting. Artnet is controlled by the Neuendorf family, which owns 26 percent of the company’s shares. A slightly larger percentage of the shares, which are traded on the German stock exchange, are owned by Rudiger Weng, who’s been campaigning to win a seat on the three-person board of directors. Weng believes he finally has the votes, which would subsequently allow him to oust C.E.O. Jacob Pabst, the 52-year-old son of Hans Neuendorf, the company’s 87-year-old founder. But late last week, the meeting was canceled without warning.