The Chicago Tribune, challenged by weaker-than-expected first-half financial results, plans to eliminate around 120 positions from the newspaper's workforce of about 3,000, Publisher and Chief Executive David Hiller said Thursday. No decision has been made on exactly how many jobs each department and operation will lose, Hiller said. But, he said, 40 or so jobs have been vacant and left unfilled since the beginning of the year, meaning roughly 80 more will be deemed unnecessary and eliminated in the coming months. "We would hope to have most of this decided by Labor Day .. and, as much as possible, completed,"...