BEIJING -- China's top economic planner in August accelerated the approval of new fixed-asset investment for major infrastructure projects to sustain economic growth.

The National Development and Reform Commission (NDRC) gave the green light to investment totaling 196.6 billion yuan (nearly 30 billion U.S. dollars) for 25 projects last month, NDRC official Zhao Chenxin said Wednesday during a press conference.

"The projects were concentrated in water conservancy, transport, energy and other social undertakings," Zhao said.

The headline figures are a considerable increase from less than 60 billion yuan in the previous month as the government ramps up spending to offset flagging private investment.

Despite returning to growth for August alone, investment by the private sector generally remained weak. In contrast, state-sector investment continued to boom due to government support, up 21.4 percent year on year during the first eight months.

To rein in the ongoing economic slowdown, the NDRC started to promote a package of investment projects in September 2014. As of July, it had given the go ahead to investment totaling 6.38 trillion yuan.