China's industrial output expanded 6.8 percent year on year in May, slower than the 7-percent rise in the previous month but still faster than the 6-percent increase in March, official data showed Thursday.

In the first five months, industrial output rose 6.9 percent, flat with that of the first four months, the National Bureau of Statistics said in a statement.

Industrial output, officially called industrial value added, is used to measure the activity of designated large enterprises with annual turnover of at least 20 million yuan (about 3 million U.S. dollars).

A breakdown of the data showed the production and supply of electricity, thermal power, gas and water reported the fastest growth at 12.2 percent among all the industries in May.

The service sector picked up pace, with its production index up 8.1 percent last month, quickening from 8 percent in April. Software, information technology, and business services maintained robust increases.