The free daily newspaper industry, which is well represented in the Bay Area, has become big enough to have an industry conference and apparently will soon have its own trade association. The conference will take place in St. Petersburg, Fla., June 18-19, and is being organized by two executives who were previously part of the Metro International chain of free dailies. The infomation sheet about the conference also says an Association of Free Daily Newspapers is in formation. The U.S. has 49 free daily newspapers, most of which were launched in the past five years. In Canada, free dailies represent 25 percent of that country’s newspaper circulation. In Europe, free papers make up 15.3 percent of that continent’s daily newspaper circulation, according to Media Life Magazine. London and Copenhagen each have five free dailes, Hong Kong and San Francisco have three, and Boston and New York have two.