China Unicom (Hong Kong) Ltd is planning to more than double the number of subscribers to its 3G service by the end of this year, said a company official.

China Unicom, the nation's second-largest mobile carrier in terms of the number of users, now provides service to more than 40 million 3G users. It hopes to have 90 million by the end of the year, said Shao Guanglu, deputy general manager of China Unicom, in the 2012 Global Mobile Internet Conference held in Beijing on Thursday.

China Unicom's revenue from 3G services reached 40 billion yuan in 2011, and the figure is expected to surpass 70 billion yuan this year, Shao said.

China Unicom has benefited from China's adoption of the WCDMA standard, the world's most widely used 3G technology. The company was the first in China to introduce legally imported Apple iPhones.

Every month since October 2011, China Unicom has consistently added more 3G users than China Mobile Ltd, China's biggest telecom carrier.

Although the popularization of 3G services is starting to pick up steam, Shao said telecom carriers worldwide are facing intensified competition from Internet companies.

The rapid development of mobile Internet and smartphone terminals has resulted in the explosive growth of data traffic, but the revenue of telecom carriers did not rise significantly because Internet companies, such as Apple and Google, grabbed up most of the profits, Shao said.

China Unicom will add 20,000 Wi-Fi hotpots this year, which will bring the total number of its Wi-Fi hotspots to 40,000.