Tribune Co. Chairman and Chief Executive Sam Zell has admitted that he made a mistake when he bought the company in a highly leveraged $8.2-billion deal in 2007. "I was too optimistic," he added in an interview with Bloomberg television. Tribune's properties include the Los Angeles Times , L.A. TV station KTLA, the Chicago Tribune and Chicago TV station WGN. The company has laid off hundreds of employees in order to make the interest payments on its $13-billion debt, even while ad sales have fallen. Asked whether he would sell off any of Tribune's assets, Zell replied, "We are seriously looking at everything because in effect the future of the newspaper industry is at risk today,"