The MVNO licence allows China Unicom to provide 3G mobile services in Hong Kong by leasing spectrum from any of the four 3G licensees.
China Unicom is the third telecoms company to receive an MVNO licence, after Hong Kong-based Trident Telecom, and China Motion Telecom International.
According to analysts, China Unicom's move into the Hong Kong market might be an attempt to learn about the MVNO model in order to then apply it to its home market.
"It's a bit of a reversal of what one might expect since Chinese carriers tend to be behind the curve," said Craig Watts, analyst at research company BDA China.
Watts speculated that China Unicom's move might be "to study first hand, rather than make profits," and to position itself in the home market, against its major competitor, China Mobile Communications.
Moreover, China Unicom's bid for an MVNO licence could hint that it is interested in establishing its presence beyond the Chinese market, he said.
At the same time putting its energy into a new initiative might also help detract from the woes the company is facing at home, he said. "China Unicom is having major trouble at home with the deployment of its CDMA network, so maybe getting an MVNO licence in Hong Kong is a way of making people stay interested," Watts said.