T&T Corp has launched AT&T Business Network, its Internet service aimed at managers, entrepreneuers and professionals: the service, at http://www.bnet.att.com, is designed to give business professionals quick access to the most useful resources on the Web. It offers reviews and links to more than 1,000 business-related sites including corporate Web sites, on-line versions of publications, Federal government sites, credit reports and bankruptcy information. It will be free, with users required to register for some specialized services, and will initially be supported by advertising. Over time, subscription or other fees will be charged for additional services. The company said the launch was the next step in the previously announced movement of the business network from AT&T’s closed proprietary Interchange Online Network to the Web. All services now on Interchange will be on the Web alone by the end of next quarter, the company said.