The New Zealand Superannuation Fund is sticking with a strong weighting to equities following a five-year review of its passive reference portfolio, which forms the basis for most of the fund's investments.

Fund manager, the Guardians of New Zealand Superannuation, expects the reference portfolio, introduced in 2009, to return 7.7 percent over 20-year periods, 2.7 percent above the risk-free Treasury bill interest rate.

The five-year review has found the portfolio's current mix of 80 percent equities and 20 percent fixed income assets remains appropriate, given the fund's long-term investment horizon. The fund, established in 2001 to help pre-fund universal super benefits, is not projected to start paying out money until 2031/32.

Guardians chair Gavin Walker said setting the reference portfolio was the most important decision the board makes, given it provides both economic return and a benchmark for active investment.


"We are prepared to weather volatility in fund returns as asset prices fluctuate in the short-term - indeed, as the fund experienced during the global financial crisis - in order to maximise long-term performance," he said.

The reference portfolio's existing 5 percent allocation to New Zealand equities will remain unchanged although the fund's actual portfolio currently holds around 7 percent in listed NZ equities and about a further 8 percent in other New Zealand assets.

Changes include increasing the allocation to global equities from 70 percent to 75 percent, of which 65 percent will be targeted at developed markets and the rest to emerging markets.

The reference portfolio's existing 5 percent allocation to global listed real estate investment trusts has been dropped, with chief investment officer Matt Whineray saying the Guardians believe the fund achieved sufficient exposure to listed real estate through its global equities, which comprise 5 percent of the reference portfolio.

It will remain 100 percent hedged to the New Zealand dollar to provide a clear performance benchmark for any active currency investments made outside of it.

Over the past five years the reference portfolio has returned 13.2 percent compared to an expected 8.5 percent. The overall fund generated an additional 3.65 percent per annum or $4.55 billion, over the same period through active investment decisions.

Currently around 70 percent of the fund is invested in line with the reference portfolio.