China's Internet giant Tencent Holdings Ltd is buying a stake in the country's second-largest online retailer in order to boost its competitive advantage in mobile Internet against its rival Alibaba Group Holding Ltd, the country's dominant player in e-commerce.

Shenzhen-based Tencent said on Monday it is injecting about $215 million in cash and its self-run e-commerce units into JD.com Inc for a 15 percent pre-IPO stake in the online retailer.

The deal, which comes ahead of JD's listing in the United States for $1.5 billion, is the latest in the rapidly growing Internet sector in China