China Unicom (Hong Kong) Ltd. (762), the country’s second-biggest wireless carrier, fell the most in two weeks in Hong Kong trading after the company added fewer customers for its high-speed mobile-phone service last month.

The carrier declined 3.7 percent to HK$10.42 as of 11:17 a.m. local time, poised for its biggest drop since June 4. Bigger rival China Mobile Ltd. (941) fell 0.2 percent, while China Telecom Corp. (728) dropped 3.1 percent.

China Unicom added 2.73 million users for its 3G, or third- generation service last month, the company reported in a Hong Kong stock exchange filing yesterday. That was fewer than the 2.92 million additions in April, and was the lowest monthly gain since September.

Growth in the pace of 3G user additions has slowed this year, China Unicom President Lu Yimin said last month. The Beijing-based carrier expects to generate more revenue from its 3G operations than from subscribers on the slower 2G network this year, he said at the time.

China Unicom was the only Chinese carrier offering Apple Inc.’s iPhone with a contract before China Telecom started sales of the device in March.

China Unicom has dropped 36 percent this year, making it the worst-performing member of Hong Kong’s benchmark Hang Seng Index. (HSI)

To contact the reporter on this story: Mark Lee in Hong Kong at wlee37@bloomberg.net

To contact the editor responsible for this story: Michael Tighe at mtighe4@bloomberg.net