Yidao accuses Didi and Kuaidi of 'writing own rules'

Alibaba Group Holding Ltd and Tencent Holding Ltd, two of the nation's three Internet behemoths, have both invested in the two apps:

Didi and Kuaidi continue to be challenged in ride-on-demand services by new rivals.

Internet giant Baidu Inc bought a stake in fast-growing international car-hailing service Uber in December as the pair chase growth in one of the world's largest transportation markets.

Uber's driver services are available in nine Chinese cities including Beijing and Shanghai, according to Candice Lo, who heads the company's expansion efforts in China.

In addition, Beijing-based rental firm CAR Inc launched a ride-on-demand service in January.

Analysts believe that CAR Inc, as one of the main private car-rental service providers, has great experience, such as driver team training, security management and standard cars, and can compete with the newly-merged company.