All cell phones designed after June 14 must adopt the universal charger interface, based on USB, otherwise they will not be approved for sale in China, according to the Ministry of Information Industry, which is responsible for enforcing the rule.

The goal is to reduce the number of chargers that are thrown away each year because of cell phone upgrades. Nearly 100 million cell phones are replaced every year in China, according to MII.

Several companies have already designed compliant phones. Local companies like Bird, Lenovo Mobile and Konka say the use of one charger will save costs on design interfaces, assuming that products for the local and export markets are separate.

However, some foreign companies may find the new standard inconvenient because they often ship the same model to different countries, said Yuxin Yang, an analyst with Beijing-based BDA China, a telecom consultancy. "The cost will rise if they redesign the models sold worldwide just for China," Yang said.

Motorola Inc. and Sony-Ericsson said they will have new models with universal chargers coming later this year. Nokia also intends to have models that comply.