In one of their largest layoff rounds ever, Alibaba Group and Tencent Holdings plan to shed tens of thousands of jobs this year as the internet companies try to cope with China's sweeping regulatory crackdown.

While Alibaba has not yet specified an overall group cutback target, Reuters reports that the e-commerce giant could lay off more than 15% of its total workforce, or approximately 39,000 workers, according to a source familiar with the company's plans.

Tencent, which owns China's top messaging app WeChat, also plans to lay off employees in some of its business units this year, according to the report. 

Its unit in charge of businesses such as video streaming and search will see a 10% -15% reduction in headcount this year, the report adds. Youku, the company's video streaming unit, is also planning layoffs.

 The slowing economy coupled with a clampdown on regulatory practices has slowed growth for most internet companies and made it difficult to raise capital and expand businesses, forcing companies such as Alibaba and Tencent to reduce their prices.