Tribune Co., Belo Corp. and Journal Register Co. said advertising sales continue to slump, signaling the newspaper industry's woes may extend this year. Advertising sales in June "are soft and we expect first-half advertising to be flat," Donald Grenesko, chief financial officer of Chicago-based Tribune, the second biggest U.S. newspaper publisher in revenue and owner of the South Florida Sun-Sentinel, said Tuesday at the Newspaper Association of America's Mid-Year Media Review in New York... A protracted slowdown may mean increased investor pressure on publishers including Tribune, which is fending off calls from its second largest shareholder to break apart the...