China probes Didi ahead of U.S. IPO

China's market regulator has launched an investigation into ride-hailing giant Didi, just as that company looks toward potentially the largest U.S. IPO this year.

That's according to sources familiar with the matter, who say Didi is the target of an antitrust probe over how it sets its prices, and any competitive practices which may have unfairly squeezed out smaller rivals.

This is the latest in a sweeping crackdown on Chinese tech giants.

Alibaba and Tencent have also been targets - and both have also invested in Didi.

In a statement, Didi said it did not comment on quote "unsubstantiated speculation from unnamed sources." China's market regular did not respond to requests for comment.

In its IPO filing made public last week, Didi said it had met with Chinese regulators already and completed the mandated self-inspection into possible legal violations.

But it warned that regulators might not be satisfied with the inspection results and the firm may be subject to penalties.

One source says Didi is also highlighting its job creation success to appease Beijing.

The company now employs about 13 million annual active drivers in China, according to its filing.

The impact of the probe on the company's U.S. IPO, expected to be the biggest Chinese share offering since Alibaba's $25 billion float in 2014, remains to be seen.