The old axiom that differences of opinion make for lively horse race betting and stock markets seems applicable this week for the first time in a long time to battered newspaper company shares. Mexican billionaire Carlos Slim has purchased a 6.4 percent stake in the New York Times Co. He told The Wall Street Journal that he is not interested in a takeover or forcing a sale. He just thinks the stock, trading lately in the low teens, is a good value. Slim is known as the Mexican Warren Buffett and not just because he is extremely rich (third wealthiest in the world, according to Forbes ). Having made a fortune in telecommunications, he practices the same value investment strategy, originated by Benjamin Graham, of buying unpopular, inexpensive stocks that he thinks have a solid chance to grow or rally. Buffett had spectacular success with a major investment in the Washington Post Co. soon after it went public in the 1970s. He has cooled on newspapers as an investment the last few years, telling a questioner at his 2006 annual meeting that the glory years had come and gone because of media fragmentation. The news wasn't all sunny for newspaper stocks this week. Goldman Sachs analyst Peter Appert issued a report Monday headed, "Just when you thought revenue trends couldn't get any worse..." He wrote that revenue declines at the public companies he follows have hit an "unprecedented" 17 percent year to year in recent months ...