China's National Council for the Social Security Fund plans to boost investment in state-owned enterprises as such investment plays a vital role in a growing portfolio.

By the end of 2011, 16 percent of the funds managed by the council were allocated to direct equity investment in SOEs and equity funds approved by the National Development and Reform Commission.

Direct equity investment is playing a more important role in a growing portfolio that was worth 869 billion yuan (US$137.1 billion), the council said yesterday.

It plans to extend the investment through private placements. The council has participated in the share placements of the Bank of Communications, the nation's fifth-biggest lender, and the China South Locomotive and Rolling Stock Co, the nation's biggest train maker.

The council said the direct equity investment will almost double from 138 billion yuan last year to 250 billion yuan between 2012 and 2015. It has also made good returns from investing in 13 equity funds