Tencent Holdings Ltd, China's biggest Internet company, reported lower-than-expected second-quarter results on Wednesday as higher marketing costs for its fledgling messaging and social media app WeChat eroded earnings.

Net profit rose 18.4 percent to 3.7 billion yuan ($601 million), the company said in a filing to the Hong Kong stock exchange. But profits fell short of the consensus of 3.9 billion yuan from analysts surveyed by Bloomberg News and 4.1 billion yuan among those polled by Reuters.

Group revenue in the second quarter rose 36.6 percent to 14.4 billion yuan.