Bad news tonight for Tribune Company shareholders: Shares in Tribune Co. tumbled Thursday after the media company reported a 6.1% drop in revenue last month on declines in both its newspaper and television businesses. Tribune, whose holdings include 26 television stations, 11 urban U.S. dailies and Spanish-language Hoy, said December revenue fell to $539 million from $574 million a year earlier. The company's stock fell $1.01, or 3.2%, to $30.80 in afternoon trading on the New York Stock Exchange. Tribune shares sank 28% in 2005. Advertising revenue in the publishing division fell 4.5%to $333 million, down from $349 million. The...