Lots of speculation today about what shareholder activist Nelson Peltz might be up to with his purchase of 2.8 million shares of Tribune Co. stock for the quarter ended June 30. That's 1.2 percent, more than enough to create a little heat. Peltz, a billionaire who has been embroiled in a boardroom battle with H.J. Heinz Co. (he's seeking five seats), is not exactly known as a wallflower. Phil Rosenthal at the Chicago Tribune described Peltz and his partner Peter May as "change agents. They tend to cut jobs, shake up management and streamline bureaucracy when they take control of a company."

Meanwhile, Chicago-based Tribune, which owns the Los Angeles Times, reported a 1.9 percent drop in publishing revenue for July. Ad revenue slipped 1.4 percent, with retail adverstising taking a particular hit from weakness in the department store and specialty merchandise categories. (And this is before plans by Macy's to cut back on its newspaper advertising this fall.) And here's something that stands out: National advertising revenue fell 3.8 percent due to weakness in the movie and telecommunications categories. But online revenue climbed 23 percent, though it's only $21 million. No breakout for specific Tribune properties. Near the close of trading, Tribune was up more than a buck and a half, which is a curiously good showing considering those weak ad numbers.