Not-for-profit funds are more concerned about maintaining their member's confidence than they are about introducing a MySuper option, a survey by the Australian Institute of Superannuation Trustees (AIST) has found.

A survey of 40 industry fund chief executives found that only 12.5 per cent identified the introduction of a MySuper option as their biggest challenge, while 32,5 per cent said maintaining member confidence was their biggest challenge.

AIST chief executive Fiona Reynolds said the results reflected the concern of chief executives about the impact of reforms, market volatility and other uncertainties on their members.

"Given the raft of reforms facing the industry and the political and economic uncertainty, both here and overseas, it's not surprising that super funds are concerned about how this might impact on their members," Reynolds said.

The survey, which was released at AIST's Australian Super Investment conference in Hobart yesterday, also showed that 7.5 per cent of funds indicated that the exit of members to self-managed super funds was their biggest challenge.

The survey showed further that 45 per cent of chief executives supports an increase in the level of investment portfolio disclosure to super fund members, while 40 per cent said disclosure was adequate.

ASIC chairman Greg Medcraft called last month for a better disclosure of portfolio holdings to members to improve member confidence in the super system.

About 55 per cent of chief executives said describing risk on the basis of the likelihood of negative returns over a prescribed period - such as 10 years - did not provide sufficient disclosure of the severity of risks.

Despite the ongoing consolidation in the super fund sector, more than 50 per cent of chief executives did not believe that scale through mergers delivered better returns to members.