BEIJING - The annual growth of China's urban fixed-asset investment continued to cool in 2015 to 10 percent year on year, down from 15.7 percent in 2014, official data showed on Tuesday.

The reading was slightly down from the 10.2-percent growth for the first 11 months of 2015, the National Bureau of Statistics (NBS) said.

This is the latest step in continued deceleration of growth for fixed-asset investment, money used to purchase and build factories, machines, property and other fixed facilities.

The figure was among economic data released by the NBS which showed annual growth of the world's second largest economy slowed to 6.8 percent in the fourth quarter of 2015 and 6.9 percent for the whole year.

Investment slowdown is believed to be one of the main reasons behind the weakness in demand and the downside risk to the Chinese economy.

Fixed-asset investment growth has been declining since reaching an annual high of 13.9 percent for the Jan-Feb period.

Fixed-asset investment in the agricultural sector jumped the fastest, up 31.8 percent year on year. It was followed by 10.6 percent growth for the service sector and 8 percent for the industrial sector, the new NBS data showed.