Media conglomerate Tribune Co., smothered by $13 billion in debt and weak prospects for generating cash through advertising, on Monday became the first major newspaper publisher to seek bankruptcy protection since the Internet began siphoning readers from traditional outlets... The company entered court protection with $13 billion in debt and $7.6 billion in assets. Zell said the company's operations will function as before during the bankruptcy protection period. He also said in his memo that the Cubs franchise is not part of the bankruptcy filing. The Cubs issued a separate statement saying that the timetable for a sale has not changed.