Senior citizens chat at a retirement home in Beijing. [Photo/Xinhua]

BEIJING - China's State Council published the final guideline on investment for the country's massive pension fund on Sunday, effectively opening the gate for its investment into the stock market.

The final plan, released after considering public opinion, allows the pension fund to be invested in new products, including domestic stock markets, but restricts the maximum proportion of investments in stocks and equities to 30 percent of total net assets.

The fund will also be used to participate in major projects and purchase shares in state-owned enterprises to gain long-term yields.

Provincial-level governments determine the capital amount to be invested first and only the institutions authorized by the State Council can operate such capital. All details shall be reported to the Ministry of Human Resources and Social Security and the Ministry of Finance.

The guideline will be effective since the day it's published.

The move is intended to create more value for the massive fund, which was previously parked in banks or invested in treasury bonds with low yields, a condition that has long spurred calls for changes as China faces a huge challenge in caring for its increasing elderly population.

Senior citizens over 65 years make up more than 10 percent of China's population and the ratio may rise to a third by 2050. A country is considered an aging society if the ratio is higher than 7 percent.

While pushing for diversified investments, the State Council stressed an "active and cautious" approach in the process. "The management of the funds must prioritize safety and firmly control risks," it reiterated.