SHANGHAI - Two Chinese taxi-hailing apps that merged in February issued a set of standards on Monday to govern their ride-on-demand service, which has run afoul of state and local regulators over passenger safety concerns.

Under the self-imposed standards issued by Didi Dache and Kuaidi Dache, drivers must have at least three years of driving experience, be screened for criminal and traffic violation records and undergo training and tests before becoming employed for ride-on-demand services.

It also laid out requirements for vehicles used for such services and required them to be monitored through GPS and the Internet. The company will also be obliged to compensate passengers for accidents that occur during trips.

Didi Dache and Kuaidi Dache announced a merger in February that could value the firm at 6 billion US dollars after a year of fierce competition for market share.

The two apps launched their respective ride-on-demand services during the second half of last year. Both taxi drivers and private car owners have signed up, but the service has been challenged by regulators as some cities banned unlicensed drivers from giving rides at the end of last year.

China's Ministry of Transport also banned private cars from taking passengers for profit in January and ordered app developers including Didi and Kuaidi to only dispatch cars owned by taxi or car-rental companies for ride-on-demand services "out of safety concerns."