AT&T and Verizon are the top two American telecoms firms in terms of brand value.
AT&T's brand valuation climbed 20% since last year.
Cheung said AT&T is trying to become more of a lifestyle brand for consumers, providing entertainment services in addition to typical telecoms offerings.
AT&T's acquisition of DirecTV in mid-2015 has helped it enrich its content offerings and maintain its leading position in the industry.
First published June 7, 2016: 8:49 PM ET
Methodology: The 2016 BrandZ ranking of the most valuable brands in the world was carried out by Millward Brown, part of advertising firm WPP. It calculates brand value by using in-depth financial data and interviews with over three million consumers around the world.
