BEIJING - China's top economic planner on Tuesday unveiled new laws allowing private investors to build projects in the energy, transportation, water and environmental protection sectors through franchising.

The rules, which will take effect from June, will "protect the legal interests of private capital and guarantee stability and continuity of franchising operations," said Li Kang, head of the National Development and Reform Commission's (NDRC) department of laws and regulations, at a press conference.

The government will encourage policy banks and financial development institutions to offer "differentiated" credit support to these franchise projects, including loans of up to 30 years.

The government is striving to boost infrastructure investment to lift growth, which slowed to a six-year low of 7 percent in the first quarter of the year. A recent official survey indicated continued weakness in the second quarter.