BEIJING - China's power use growth, a key barometer of economic activity, continued to accelerate in September due to more consumption by the service sector, an increasingly significant driver of the Chinese economy, official data showed Thursday.

A total of 496.5 billion kilowatt hours of electricity was consumed last month, up 6.9 percent year on year, according the National Development and Reform Commission (NDRC).

The growth was in sharp contrast with a 0.1 percent drop in the same period of 2015 and extended year-on-year increases seen since July.

Electricity consumed by the service sector expanded rapidly in September, with information, computing and software industries surging 17.1 percent year on year, NDRC official Zhao Chenxin said during a press conference.

Power use by commerce, hospitality and catering industries grew 14.5 percent, while financial and real estate industries as well as business and residential services rose 15.5 percent.

In the first three quarters of the year, the service sector accounted for 66.7 percent of power use growth, well above the 31.3 percent for the industrial sector.

China has been re-balancing its economic structure from manufacturing and investment to services and consumption.

The service sector grew 7.5 percent in the first half of the year, accounting for 54.1 percent of the overall economy, up 1.8 percentage points from a year earlier, official figures show.

In the first three quarters, the agricultural, industrial and service sectors all used more electricity, according to the NDRC. Residential power consumption also went up rapidly.

During that period, the nation's total power use grew 4.5 percent year on year, compared with a 0.8 percent rise a year earlier, Zhao said.