Beijingers may soon be able to punch their mobile phones to pay for tickets on public transit, sources with the city's public transportation group said on Tuesday.

A variant of a mobile phone's SIM card is being developed and tested, said Xu Fa, a marketing manager of the Beijing Municipal Administration and Communication Card Co Ltd.

Xu said the card is now being tested on a new Nokia mobile phone, but he didn't indicate when it might come into use.

A year ago the company introduced the so-called smart card that allows commuters to swipe a credit-card to ride the transit system. As of May 11, 11.43 million smart cards have been issued in Beijing, said Wang Lianqi, general manager of the company.

In the future Beijingers may also be able to use their smart cards to pay for their utilities such as water, electricity, and gas, said Wang.

"There is no problem with the technology but we need a seamless connection between different public services. The work is in progress." said Wang.