By Yifan Wang

China Unicom (Hong Kong) Ltd. said its net profit for the first half of the year rose 10% from a year earlier, thanks to increased revenue and a lower cost-to-sales ratio.

The telecom operator posted a net profit of 7.57 billion yuan ($1.09 billion) for the first six months of the year.

Revenue rose 3.8% from a year earlier to CNY150.40 billion, mainly driven by strong growth from its internet business, which includes data-center operations and cloud-computing services.

Service revenue, the firm's largest source of income, rose 4.0% from a year earlier.

Write to Yifan Wang at yifan.wang@wsj.com