Hutchison Telecommunications Hong Kong Holdings Ltd, a unit of investment conglomerate Hutchison Whampoa Ltd, operates mobile services under a branch in Hong Kong known as Three.

Not all wireless network operators enjoy sound and stable growth rates in Asia's financial hub. Hutchison Telecommunications said 2013 net profit fell 25 percent to HK$916 million ($118.1 million) because of a weak market response to smart mobile phones and devices.

"Hong Kong's mobile service market is pretty saturated. So it is not an easy job for carriers to maintain stable development," said Colin Light, digital consulting leader at PricewaterhouseCoopers. It is particularly hard for smaller telecom operators to move up a notch when bigger ones have a tight grip on market share, he said.

According to the government's Office of the Communications Authority, the mobile subscriber penetration rate in Hong Kong was 241 percent as of January 2014, more than two times that of the mainland. It indicates that everyone in Hong Kong has at least two mobile phones.

Lin said it would be quite difficult for China Mobile to overtake local competitors and gain the top position in Hong Kong, but that the market provides valuable experience for developing businesses in the mainland.

"Hong Kong's telecom market is mature and fully competitive. We gain experience from this fierce competition and acquire in-depth understanding of product development," said Lin.

In addition, by launching a merged fourth-generation network in Hong Kong in 2012, China Mobile was able to test a domestic 4G standard in a real commercial environment, paving the way for a nationwide commercial rollout a year later.

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