AT&T Inc. is one of the world's largest telecommunications holding companies and is the largest in the United States. Operating globally under the AT&T brand, AT&T companies are recognized as the leading worldwide providers of IP-based communications services to business and as leading U.S. providers of high speed DSL Internet, local and long distance voice, and directory publishing and advertising services. AT&T Inc. holds a 60 percent ownership interest in Cingular Wireless, which is the No. 1 U.S. wireless services provider with 57.3 million wireless customers.