South Korea's National Pension Service (NPS) will increase its overseas investments to 60% of total assets by 2028, the welfare ministry said on Friday.

The NPS will also prepare a portfolio-setting mechanism to expand alternative investments more easily, employ more personnel for such investments, and diversify its portfolio with mid-risk, mid-return investments.

With the measures, the NPS aims to improve its investment returns by one more percentage point to help sustain the fund, which is expected to be depleted by 2055 due to a fast-ageing population.

The world's third-largest public pension fund held 989.3 trillion won ($732.8 billion) in assets at the end of July, with 50.3% of the total accounting for foreign assets. ($1 = 1,350.0900 won) (Reporting by Jihoon Lee; Editing by Jacqueline Wong and Sonali Paul)