China Unicom is cooperating with Myanmar's telecommunications operators to build the underwater cable, said Jiang Zhengxin, vice general manager of China United Telecommunications Corp., parent of China Unicom.
The cable will carry information and data flow between China and the ASEAN (Association of Southeast Asian Nations), he said, without giving further details.
A land cable between China and Myanmar is also under construction at a cost of 50 million U.S. dollars, he added.
Jiang made the remarks on the sidelines of the China-ASEAN Information Harbor Forum, which kicked off in Nanning, capital of south China's Guangxi Zhuang Autonomous Region, on Sunday.
The forum focuses on cooperation between China and Southeast Asia in the Internet and technology industries.