SHANGHAI - Shanghai, which has one of the most rapidly aging populations of any Chinese city, will expand its old-age subsidy next year to cover 2.7 million citizens above 65.

The city government announced on Thursday that a unified subsidy system will replace the existing district-based food subsidies and free bus passes for residents above 70, which in total benefit 1.7 million people.

Under the new system, residents above 65 will receive monthly payments ranging from 50 yuan to 500 yuan ($7.8-78), according to their age.

The city government will allocate 3.3 billion yuan every year for the new subsidies, up from 850 million yuan for the current old-age benefits.

As of the end of 2013, the number of people aged 60 or above in Shanghai stood at 3.88 million, or 27 percent of the registered population, according to the city's civil affairs authority.

China as a whole had 212 million over-60s, or 15.5 percent of the total population, at the end of 2014. The number is expected to grow by around 10 million per year.